An aerosol generator comprising an airflow guiding element extending into a heating chamber

Abstract

An aerosol generating device (100) having an oral end for receiving an aerosol generating article is provided. The aerosol generating device comprises a heating chamber (108) for receiving an aerosol generating article at the oral end (102) of the device. The aerosol generating device comprises a heating element (110) provided around or in the vicinity of the heating chamber for heating the aerosol generating article received within the heating chamber. The aerosol generating device comprises an airflow guiding element (20) located within the heating chamber and extending in the longitudinal direction towards the oral end of the device. The airflow guiding element is configured to be inserted into the aerosol generating article when 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 comprising a rod of an aerosol generating substrate adapted to generate an inhalable aerosol upon heating. 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, the aerosol is generated by transferring heat from a heat source to a physically separated aerosol generating substrate or material, which may be in contact with the heat source, within the heat source, around the heat source, or downstream of the heat source. During use of the aerosol generating article, volatile compounds are released from the aerosol generating substrate by heat transfer from the heat source and entrained in the air drawn through the aerosol generating article. The released compounds condense as they cool to form an aerosol.

[0003] In many prior art documents, an aerosol generating device for consuming an aerosol generating article is disclosed. Such devices include, for example, an electrically heated aerosol generating device in which aerosol is generated by heat transfer from one or more electrical heater elements of the aerosol generating device to an aerosol generating substrate of a heatable aerosol generating article. For example, an electrically heated aerosol generating device has been proposed that includes an internal heater blade adapted to be inserted into the aerosol generating substrate. It is also well known to use an aerosol generating article in combination with an external heating system. For example, International Application No. 2020 / 115151 describes the provision of an external heating body disposed around the periphery of an aerosol generating article when the aerosol generating article is received within a cavity of the aerosol generating device. Alternatively, an inductive heat-generating aerosol generating article including an aerosol generating substrate and a susceptor disposed within the aerosol generating substrate has been proposed by International Application No. WO-A-2015 / 176898.

[0004] Generally, it can be difficult to provide efficient heating of the aerosol generating substrate across the entire length of the substrate rod. While the portion of the substrate closest to the heating element is necessarily heated most effectively, if heat transfer through the substrate is incomplete, it means that the portion of the substrate furthest from the heating element may not be heated effectively. Thus, the generation of aerosol 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 temperature high enough to generate aerosol during use. For example, as described above, when an external heating body is used to heat the rod of an aerosol generating substrate, the central portion of the rod of the aerosol generating substrate is less likely to generate as much aerosol as the outer portion of the rod, and in some cases, may not generate any aerosol at all. Therefore, overall, the generation of aerosol from the aerosol generating rod can be inefficient, and a portion of the aerosol generating substrate can potentially be wasted.

[0005] In addition, generally, the aerosol is not immediately generated by the aerosol generation substrate when the heating element is activated. This is because there is a preheating time after the activation of the heating element, during which the aerosol generation substrate is heated to the temperature required for aerosol generation. Therefore, there can be a relatively long duration between the activation of the heating element and the generation of a sensibly acceptable aerosol for inhalation by the user.

[0006] Therefore, it is desirable to provide an aerosol generating article having an aerosol generation substrate that is adapted to provide more efficient aerosolization of the aerosol generation substrate and reduces waste of substrate materials such as tobacco. It is also desirable to provide such an aerosol generating article that can achieve a relatively short preheating time, so that a sensibly acceptable aerosol can be delivered to the user immediately after the start of heating of the aerosol generation substrate. It would be desirable to provide such an aerosol generating article that can provide optimized delivery of the aerosol from the aerosol generation substrate. It would be particularly desirable to provide such an aerosol generating article in a relatively simple design that can be manufactured in a cost-effective manner and incorporated into existing product designs. It would be even more desirable to provide such an article that can be easily adapted to be heated by various types of heating devices including induction heating devices and resistance heating devices. Summary of the Invention

[0007] An aerosol generating device having a mouth-side end for receiving an aerosol generating article is provided. The aerosol generating device may comprise a heating chamber for receiving the aerosol generating article at the mouth-side end of the device. The aerosol generating device comprises a heating chamber for receiving and heating the aerosol generating article. The aerosol generating device may comprise an airflow guiding element located within the heating chamber and extending in the longitudinal direction towards the mouth-side end of the device. The airflow guiding element may comprise an elongated body. When the airflow guiding element receives an article within the heating chamber, it may be inserted into the aerosol generating article or received within the aerosol generating article. The width or outer diameter of the airflow guiding element may vary along its length. The first portion of the airflow guiding element may have a width or outer diameter corresponding to the maximum width or outer diameter of the airflow guiding element. The second portion of the airflow guiding element located upstream of the first portion may have a width or outer diameter smaller than the maximum width or outer diameter of the airflow guiding element.

[0008] An aerosol generating device having a mouth-side end for receiving an aerosol generating article is provided. The aerosol generating device may comprise a heating chamber for receiving the aerosol generating article at the mouth-side end of the device. The aerosol generating device may comprise a heating element provided around or in the vicinity of the heating chamber for heating the aerosol generating article received within the heating chamber. The aerosol generating device may comprise an airflow guiding element located within the heating chamber and extending in the longitudinal direction towards the mouth-side end of the device. When received within the heating chamber, the airflow guiding element may be configured to be inserted into the aerosol generating article. That is, when the article is received within the heating chamber, the airflow guiding element may be received within the aerosol generating article.

[0009] According to the present invention, there is provided an aerosol generating device having an oral end for receiving an aerosol generating article. The aerosol generating device comprises a heating chamber for receiving and heating the aerosol generating article. The aerosol generating device comprises an airflow guiding element located within the heating chamber and extending in the longitudinal direction towards the oral end of the device. The airflow guiding element may be inserted into the aerosol generating article or received within the aerosol generating article when an article is received within the heating chamber. The width or outer diameter of the airflow guiding element varies along its length. A first portion of the airflow guiding element has a width or outer diameter corresponding to the maximum width or outer diameter of the airflow guiding element. A second portion of the airflow guiding element located upstream of the first portion has a width or outer diameter smaller than the maximum width or outer diameter of the airflow guiding element.

[0010] There is also provided an aerosol generating system comprising an aerosol generating device according to the present disclosure and an aerosol generating article that generates an inhalable aerosol upon heating. The aerosol generating article may include an aerosol generating substrate. The aerosol generating substrate may be in the form of a 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. When the aerosol generating article is received within the heating chamber of the device, the airflow guiding element may extend longitudinally into or protrude into the substrate cavity. As a result, an airflow channel may be defined between the outer surface of the airflow guiding element and the inner surface of the aerosol generating substrate.

[0011] According to the present invention, there is also provided an aerosol generating system comprising an aerosol generating device according to the present disclosure and an aerosol generating article that generates an inhalable aerosol upon heating. The aerosol generating article includes an aerosol generating substrate. The aerosol generating substrate is in the form of a 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. When the aerosol generating article is received within the heating chamber of the device, the airflow guiding element extends longitudinally into the substrate cavity. An airflow channel is defined between the outer surface of the airflow guiding element and the inner surface of the aerosol generating substrate.

[0012] As used herein in the context of the present disclosure, the term "aerosol generating article" is used to describe an article that includes an aerosol generating substrate that generates an inhalable aerosol upon heating and delivers it to a user.

[0013] As used herein in the context of the present disclosure, the term "aerosol generating substrate" is used to describe a substrate that includes an aerosol generating material having the ability to release a volatile compound that can generate an aerosol upon heating.

[0014] As used herein in the context of the present disclosure, the term "aerosol" is used to describe a dispersion of solid particles, or droplets, or a combination of solid particles and droplets in a gas. The aerosol may be visible or invisible. The aerosol may include not only vapors of substances that are normally liquid or solid at room temperature, but also solid particles or liquid droplets, or a combination of solid particles and liquid droplets.

[0015] An aerosol generating article according to the present disclosure has a downstream end through which an aerosol exits the aerosol generating article for delivery to a user during use. The downstream end of the aerosol generating article may also be referred to as the proximal end or the mouth-side end of the aerosol generating article. During use, the user directly or indirectly inhales the downstream end of the aerosol generating article to inhale the aerosol generated by the aerosol generating article.

[0016] An aerosol generating article according to the present disclosure has an upstream end. The upstream end is opposite 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 parts of the 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 positions between the upstream end and the downstream end of the aerosol-generating article or device. The downstream end of the aerosol-generating device may correspond to the mouth-side end or the 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 that is on the opposite side of the downstream end.

[0018] As used herein in connection with the present disclosure, the term "longitudinal direction" is used to mean the direction between the upstream end of the aerosol-generating article or device and the downstream end on the opposite side thereof.

[0019] As used herein in connection with the present disclosure, the term "transverse direction" 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 the cross-section of the aerosol-generating article, the aerosol-generating article or its components, unless otherwise specified.

[0021] As used herein with reference to the present disclosure, the term "radial direction" describes a direction that extends in a plane perpendicular to the central longitudinal axis of the aerosol-generating article and is defined by a line passing through the point where the plane perpendicular to the central longitudinal axis intersects. 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 substrate element" generally mean an elongated element that defines a lumen, cavity or air flow passage along its longitudinal axis. In particular, the term "tubular" is used with respect to a tubular element that has a substantially cylindrical cross section and defines at least one air flow conduit that establishes unbroken fluid communication between the upstream end of the tubular element and the downstream end of the tubular element. However, of course, alternative shapes (e.g., alternative cross-sectional shapes) of the tubular element may be possible. The hollow tubular element can be an individual discrete element of the aerosol generating article having a defined length and thickness. The term "hollow tubular substrate" or "hollow tubular substrate 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" encompasses any material formed by the aggregation of tobacco material particles. The homogenized tobacco material may be manufactured by casting, extrusion, papermaking processes, or any suitable process known in the art.

[0024] As used herein with reference to the present disclosure, the term "tobacco particle" describes particles of any plant member of the genus Nicotiana. The term "tobacco particle" includes ground or powdered tobacco leaf lamina, ground or powdered tobacco leaf stems, tobacco dust, tobacco fines, and other particulate tobacco by-products formed during the processing, handling, and shipping of tobacco. Preferably, substantially all of the tobacco particles are derived from tobacco leaf lamina. In contrast, isolated nicotine and nicotine salts, while compounds derived from tobacco, are not considered tobacco particles for the purposes of the present disclosure.

[0025] Providing an elongated airflow guiding element extending into or protruding into the heating chamber of an aerosol generating device provides centering means to ensure that the aerosol generating article is inserted into the device. In particular, those having an open hollow upstream end and a hollow aerosol generating substrate provide centering means to ensure substantial alignment with the central longitudinal axis of the heating chamber. This can be particularly important for devices having a heater located around or near the periphery of the heating chamber to heat the received aerosol generating article from the outside. The airflow guiding element can assist in centering the aerosol generating article and its substrate with respect to the heater of the device such that the entire periphery of the aerosol generating substrate is substantially positioned at a uniform distance from the surrounding heater.

[0026] In the aerosol generating article and aerosol generating system of the present disclosure, by providing a substrate element in tubular form, advantageously, the amount of tobacco material in the aerosol generating substrate can be optimized, and as a result, the aerosol can be efficiently generated from the aerosol generating substrate upon heating. Further, due to the tubular form, in particular in an aerosol generating device provided with external heating means, the central portion of the homogenized tobacco material, which may not be heated as effectively towards the outer portion, is removed. Thus, overall, the amount of tobacco material can be significantly reduced compared to a conventional solid plug of homogenized tobacco material, and tobacco waste can be reduced. For example, the amount of tobacco material used in the hollow tubular substrate element of the aerosol generating article according to the present disclosure can be reduced by up to 40 percent compared to the amount of tobacco material used in the solid plug of the substrate of a conventional aerosol generating article, while it has been found that a similar delivery of the aerosol to the consumer can be maintained.

[0027] The amount of tobacco material provided within the substrate can be readily adapted by controlling parameters of the hollow tubular substrate element, such as the density and wall thickness of the peripheral wall of the hollow tubular substrate element. In this way, it is possible to adapt the hollow tubular substrate element such that it coincides with the heating zone of an associated aerosol generating device. Thus, the proportion of the aerosol generating substrate that can be heated to the temperature required for aerosol generation is maximized such that the generation of aerosol from the aerosol generating substrate is optimized.

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

[0029] When an aerosol-generating article comprising an open upstream end and a hollow tubular aerosol-generating substrate is received within an aerosol-generating device comprising an airflow guiding element extending in a longitudinal direction within and along a heating chamber, the article can receive the airflow guiding element of the device through the upstream end of the article such that the airflow guiding element extends longitudinally within 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 interior of the aerosol-generating substrate, such that air entering the substrate cavity is encouraged to flow close to the inner surface of the aerosol-generating substrate. The protrusion of the airflow guiding element into the cavity effectively provides an airflow path having a reduced cross-section relative to the cross-section of the cavity, such that air entering the cavity can be locally accelerated as it flows through such an airflow path in accordance with Bernoulli's principle. Such local airflow acceleration may enhance the extraction of aerosol-forming components from the heated aerosol-generating substrate, which is particularly important for a tubular substrate having an empty core. As a result, this airflow arrangement improves aerosol delivery from articles having a hollow tubular substrate, while shortening the time required for the substrate to generate a perceptually acceptable aerosol after first being heated, and reducing the potential waste of substrate material that did not contribute to aerosol generation and manufacturing costs.

[0030] Furthermore, providing an upstream portion of the airflow guiding element having a diameter smaller than a downstream portion of the airflow guiding element having a diameter corresponding to the maximum diameter of the airflow guiding element ensures that the air flowing around the airflow guiding element encounters a reduction in the cross-sectional area of the airflow channel defined between the outer surface of the airflow guiding element and the inner surface of the hollow aerosol generating substrate of the aerosol generating article received within the device cavity of the aerosol generating device, and as a result of the increase in the diameter of the airflow guiding element, further proceeds along the airflow guiding element and is not at the base (or upstream end or proximal end) of the airflow guiding element. This increase in diameter or width obstructs the airflow and pushes the air near the inner surface of the received hollow aerosol generating substrate, thereby promoting local turbulent airflow and local airflow acceleration to form between the airflow guiding element and the inner surface of the hollow aerosol generating substrate, particularly at the location where the diameter or width increases. This can improve aerosol generation as a result of enhanced mixing of the air with the aerosol-forming components released from the aerosol generating substrate upon heating.

[0031] As described above, the aerosol generating article according to the present disclosure comprises a hollow tubular substrate element. The hollow tubular substrate element is preferably formed of a homogenized tobacco material. The hollow tubular substrate element is preferably formed of one or more layers of homogenized tobacco material such as cast leaf.

[0032] The hollow tubular substrate element preferably includes overlapping layers of two or more homogenized tobacco materials, and more preferably is formed from three or more overlapping layers of homogenized tobacco materials.

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

[0034] The plurality of overlapping layers of homogenized tobacco material preferably directly overlap each other such that adjacent layers are in direct contact with each other without an intermediate layer.

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

[0036] The layers of homogenized tobacco material are preferably in the form of sheets. As used herein with respect to the present disclosure, the term "sheet" describes a thin, layer-like element having a width and length that are substantially greater than its thickness.

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

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

[0039] For example, the hollow tubular substrate element may have a length of from about 5 millimeters to about 30 millimeters, or from about 7 millimeters to about 25 millimeters, or from about 10 millimeters to about 20 millimeters.

[0040] The hollow tubular substrate element preferably has a length of about 12 millimeters.

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

[0042] Preferably, the ratio of the length of the hollow tubular substrate element to the total length of the aerosol generating article can be 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 can be 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 can be 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 can be at most 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 can be at most 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 can be at most about 0.5.

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

[0045] Preferably, the hollow tubular substrate element has an outer diameter that is less than the outer diameter of the aerosol generating article.

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

[0047] Preferably, the hollow tubular substrate element has an outer diameter of at most about 9 millimeters, or at most about 8 millimeters, or at most about 7.5 millimeters.

[0048] For example, the hollow tubular substrate element may have an outer diameter from about 5 millimeters to about 9 millimeters, or from about 5.5 millimeters to 8 millimeters, or from about 6 millimeters to 7.5 millimeters.

[0049] The outer diameter of the hollow tubular substrate element is preferably substantially constant along the length of the hollow tubular substrate. Alternatively, different portions of the hollow tubular substrate 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 in the transverse direction of the aerosol-generating article or a component thereof at a position along the length of the aerosol-generating article or the component. When a range or value of the outer diameter of the aerosol-generating article or a component thereof is described herein, the outer diameter of the aerosol-generating article or the component thereof along the entire length of the aerosol-generating article or the component may be within the same range or may have the same value. In other words, when a range or value of the outer diameter of the aerosol-generating article or a component thereof is described herein, the outer diameter of the aerosol-generating article or the component thereof at all positions along the length of the aerosol-generating article or the component may be within the same range or may have the same value.

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

[0052] The hollow tubular substrate element has a peripheral wall defining a cavity or substrate cavity in the longitudinal axis direction. The wall thickness of the hollow tubular substrate element may be selected based on the desired amount of tobacco material within the hollow tubular substrate. The wall thickness of the hollow tubular substrate element may also be selected such that the hollow tubular substrate element has sufficient rigidity to be self-supporting. The wall thickness of the hollow tubular substrate may also be selected such that the cavity in the longitudinal axis direction has a cross-sectional area that provides a desired draw resistance (RTD) to the hollow tubular substrate element.

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

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

[0055] For example, the hollow tubular substrate element may have a wall thickness that is from about 4 percent to about 40 percent of the outer diameter of the hollow tubular substrate element, or from about 5 percent to about 30 percent of the outer diameter of the hollow tubular substrate element, or from about 6 percent to about 20 percent of the outer diameter of the hollow tubular substrate element.

[0056] The hollow tubular substrate element preferably has a wall thickness of about 7 percent of the outer diameter of the hollow tubular substrate element.

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

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

[0059] For example, the hollow tubular substrate element may have a wall thickness from about 0.3 millimeter to about 3 millimeters, or from about 0.35 millimeter to about 2 millimeters, or from about 0.4 millimeter to about 1 millimeter.

[0060] The hollow tubular substrate element may have a wall thickness from about 0.5 millimeter to about 2 millimeters. The hollow tubular substrate element may have a wall thickness from about 1 millimeter to about 2 millimeters.

[0061] The hollow tubular substrate element may have a wall thickness of about 0.5 millimeters. The hollow tubular substrate element may have a wall thickness of about 1 millimeter.

[0062] As described above, the longitudinal cavity provides an unrestricted flow channel through the hollow tubular substrate element. This means that the hollow tubular substrate element provides a negligible level of draw resistance (RTD). The term "negligible level of RTD" is used to represent an RTD of less than 1 mmH2O per 10 millimeters of the length of the hollow tubular substrate element, preferably less than 0.4 mmH2O per 10 millimeters of the length of the hollow tubular substrate element, and more preferably less than 0.1 mmH2O per 10 millimeters of the length of the hollow tubular substrate element.

[0063] Therefore, the longitudinal cavity should not include any components that would impede the flow of air. The internal longitudinal cavity is preferably substantially empty. More preferably, the longitudinal cavity is empty.

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

[0065] The longitudinal cavity extends between both ends of the hollow tubular substrate element and is preferably open at both the upstream and downstream ends. The open upstream end may provide the main air intake for the consumer to draw air through the aerosol-generating article when smoking the article. The longitudinal cavity thus provides the main passage for the flow of air and aerosol through the article.

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

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

[0068] For example, the aerosol generating substrate can have a length of from about 10 millimeters to about 40 millimeters, or from about 12 millimeters to about 37 millimeters, or from about 15 millimeters to about 35 millimeters.

[0069] The diameter of the cavity in the major axis direction corresponds to the inner diameter of the hollow tubular substrate element.

[0070] The cavity in the major axis direction may have a diameter of at least about 1 millimeter, at least about 2 millimeters, or at least about 3 millimeters.

[0071] The cavity in the major axis direction may have a diameter of up to about 8 millimeters, or up to about 7 millimeters, or up to about 6.5 millimeters.

[0072] For example, the cavity in the major axis direction may have a diameter of from about 1 millimeter to about 8 millimeters, or from about 2 millimeters to about 7 millimeters, or from about 3 millimeters to about 6.5 millimeters.

[0073] The cavity in the major axis direction may have a diameter of about 6 millimeters.

[0074] The diameter of the cavity in the major axis direction may be selected such that the volume of the cavity is large enough to provide a desired level of air flow while maintaining a sufficient wall thickness. This is necessary for specifications such that a sufficient amount of tobacco material is provided within the hollow tubular substrate element and the hollow tubular substrate element has sufficient rigidity to be self-supporting.

[0075] The cavity in the major axis direction preferably has a substantially constant cross-sectional shape and size along the length of the hollow tubular substrate. However, one or both of the cross-sectional shape and size of the cavity in the major axis direction may vary along the length of the hollow tubular substrate element.

[0076] The cavity in the long axis direction preferably has a substantially circular cross-section. Alternatively, the cavity in the long axis direction may have a substantially elliptical cross-section.

[0077] The cavity in the long axis direction may have a constant diameter along the length of the hollow tubular substrate element. However, the diameter of the cavity in the long axis direction may vary along the length of the hollow tubular substrate element.

[0078] The central longitudinal axis of the hollow tubular substrate element is preferably aligned with the central longitudinal axes of other elements of the aerosol generating article, such as other components of the aerosol generating substrate and components of the downstream section. For example, the central longitudinal axis of the hollow tubular substrate element is preferably aligned with the central longitudinal axes of both the upstream and downstream elements. Preferably, the central longitudinal axis of the hollow tubular substrate element is substantially aligned with the central longitudinal axis of the aerosol generating article.

[0079] The hollow tubular substrate element comprises one or more susceptor elements positioned in contact with the peripheral wall for the inductive heating of the homogenized tobacco material during use.

[0080] As used herein, the term "susceptor element" refers to an element that includes a material having the ability to convert electromagnetic energy into heat. When the susceptor element is positioned within an alternating electromagnetic field, the susceptor is heated. The heating of the susceptor element can be the result of at least one of the hysteresis losses and eddy currents induced within the susceptor, depending on the electrical and magnetic properties of the susceptor material.

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

[0082] The susceptor element can include any suitable material. The susceptor element can be formed from any material that can be inductively heated to a temperature sufficient to release volatile compounds from the aerosol-generating substrate. Suitable materials for an elongate susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium, and composites of metallic materials. Some susceptor elements include metal or carbon. Advantageously, the susceptor element can include or consist of a ferromagnetic material such as ferromagnetic iron, ferromagnetic steel or stainless steel, ferromagnetic particles, and ferrite. A suitable susceptor element is or can include aluminum. The susceptor element preferably includes a ferromagnetic material or a paramagnetic material in an amount of more than about 5 percent, preferably more than about 20 percent, more preferably more than about 50 percent or more than about 90 percent. Some elongate susceptor elements can be heated to a temperature in excess of about 250 degrees Celsius.

[0083] The aerosol-generating article according to the present disclosure may further include an upstream section located upstream of the rod of the aerosol-generating substrate. The upstream section is preferably located immediately upstream of the rod of the aerosol-generating substrate. The upstream section preferably extends between the upstream end of the aerosol-generating article and the rod of the aerosol-generating substrate. The upstream section may include one or more upstream elements located upstream of the rod of the aerosol-generating substrate. Such one or more upstream elements are described in the present disclosure.

[0084] The aerosol-generating article of the present disclosure preferably includes 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 the upstream element serves to prevent any loss of the substrate, which can be advantageous, for example, when the substrate contains particulate plant material.

[0086] When the aerosol-generating substrate comprises shredded tobacco such as cigarette cut filler, the upstream section or an element thereof may additionally serve to prevent loss of loose particles of tobacco from the upstream end of the article. This can be particularly important, for example, when the density of the shredded tobacco is relatively low.

[0087] The upstream section or an upstream element thereof may also provide some protection to the aerosol-generating substrate during storage, to at least some extent cover the upstream end of the aerosol-generating substrate which might otherwise be exposed.

[0088] In the case of an aerosol-generating article intended to be inserted into a cavity in an aerosol-generating device such that the aerosol-generating substrate can be externally heated within the cavity, the upstream section or an upstream element thereof may advantageously facilitate the insertion of the upstream end of the article into the cavity. Inclusion of an upstream element may additionally protect the end of the rod of the aerosol-generating substrate during insertion of the article into the cavity, thereby minimizing the risk of damage to the substrate.

[0089] The upstream section or an upstream element thereof may also provide an improved appearance to the upstream end of the aerosol-generating article. Further, if desired, the upstream section, or an upstream element thereof, may be used to provide information about the aerosol-generating article such as the brand, flavor, content, or details of the aerosol-generating device in which the aerosol-generating article is intended to be used.

[0090] The upstream element may be a porous plug element. The upstream element may be made of a porous material or may comprise a plurality of openings. This can be achieved, for example, by laser perforation. The plurality of openings are preferably uniformly distributed across the cross-section of the upstream element. The porosity or permeability of the upstream element may advantageously be designed to provide an aerosol-generating article having a particular overall draw resistance (RTD) that does not substantially affect 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 through suitable ventilation means provided within the wrapper and into the rod of the aerosol generating substrate.

[0092] The upstream element may be formed of a solid cylindrical plug element having a filled cross-section. Such a plug element may be referred to as a "plane" element. The solid plug element may be porous as described above, but does not have a tubular form and thus does not provide a flow channel in the long axis direction. The solid plug element preferably has a substantially uniform cross-section.

[0093] The upstream element may be formed from a hollow tubular segment that defines a longitudinal cavity providing an unrestricted flow channel. The upstream element, as described above, can provide protection against the aerosol generating substrate while having a minimal effect on the overall draw resistance (RTD) and filtration characteristics of the article.

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

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

[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 be made of the same material as that used for one of the other components of the aerosol-generating article, such as, for example, 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, cardboard, zeolites, or an aerosol-generating substrate. The upstream element may include a plug of cellulose acetate. The upstream element may comprise a hollow acetate tube or a cardboard tube.

[0097] Preferably, the upstream section or its upstream element has an outer diameter that is substantially equal to the outer diameter of the aerosol-generating article. Preferably, the outer diameter of the upstream section or its upstream element is from 5 millimeters to 8 millimeters, more preferably from 5.25 millimeters to 7.5 millimeters, and even more preferably from 5.5 millimeters to 7 millimeters.

[0098] Preferably, the upstream section or the upstream element has a length of from about 2 millimeters to about 10 millimeters, more preferably from about 3 millimeters to about 8 millimeters, and even more preferably from about 2 millimeters to about 6 millimeters. In a particularly preferred embodiment, the upstream section or the upstream element has a length of 5 millimeters. The length of the upstream section or the upstream element can advantageously vary to provide the desired overall length of the aerosol-generating article. For example, if it is desirable to reduce the length of one of the other components of the aerosol-generating article, the length of the upstream section or the upstream element may be increased to maintain the same overall length of the article.

[0099] In addition, in the case of an article intended to be externally heated, the length of the upstream section or its upstream element can be used to control the position of the aerosol-generating article within the cavity of the aerosol-generating device. This advantageously ensures that the position of the aerosol-generating substrate within the cavity can be optimized for heating and that the position of any ventilation can also be optimized.

[0100] The upstream section is preferably surrounded by a wrapper such as a plug wrap. The wrapper surrounding the upstream section is preferably a hard plug wrap, for example, a plug wrap having a basis weight of at least 80 grams per square meter (gsm), or at least 100 gsm, or at least 110 gsm. Thereby, structural rigidity is provided to the upstream section.

[0101] The upstream section is preferably connected, by the outer wrapper described herein, to the rod of the aerosol-generating substrate and, optionally, to at least a portion of the downstream section.

[0102] Preferably, the aerosol-generating article according to the present disclosure described herein is adapted for use in an electrically-operated aerosol-generating system in which the aerosol-generating substrate of the heated aerosol-generating article is heated by an electrical heat source. As described herein, an electrically-operated aerosol-generating system comprising an induction heating device also comprises an aerosol-generating article having an aerosol-generating substrate and a susceptor in thermal proximity to the aerosol-generating substrate. The susceptor may be in direct contact with the aerosol-generating substrate, and heat may be transferred from the susceptor to the aerosol-generating substrate mainly by conduction. Examples of electrically-operated aerosol-generating systems having an aerosol-generating article having an induction heating device and a susceptor are described in WO A1-95 / 27411 and WO A1-2015 / 177255.

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

[0104] In other words, an aerosol generating device may be provided that includes a heating chamber for receiving an aerosol generating article and a heating element provided around or in the vicinity of the heating chamber.

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

[0106] The expression "received therein" may refer to the fact that a component or element is received, either completely or partially, within another component or element. For example, the expression "the aerosol-generating article is received within the device cavity" refers to the aerosol-generating article being received, either completely or partially, within the device cavity of the aerosol-generating article. When the aerosol-generating article is received within the device cavity, the aerosol-generating article may abut against the distal end of the device cavity. When the aerosol-generating article is received within the device cavity, the aerosol-generating article may be substantially proximate to the distal end of the device cavity. The distal end of the device cavity may be defined by an end wall.

[0107] When received within the device or the device cavity (or the heating chamber), the aerosol-generating article may be configured to project or extend beyond the mouth-side end of the aerosol-generating device. The length of the aerosol-generating article may be longer than the length of the device cavity (or the heating chamber). This facilitates the insertion and removal of the article from the device, and allows the mouth-side end portion of the article to extend beyond the device from which the user can draw the aerosol.

[0108] The length of the device cavity may be from about 15 millimeters to about 80 millimeters. Preferably, the length of the device cavity is from about 20 millimeters to about 70 millimeters. More preferably, the length of the device cavity is from about 25 millimeters to about 60 millimeters. More preferably, the length of the device is from about 25 millimeters to about 50 millimeters.

[0109] The length of the device cavity may be from about 25 millimeters to about 29 millimeters. Preferably, the length of the device cavity is from about 25 millimeters to about 29 millimeters. More preferably, the length of the device cavity is from about 26 millimeters to about 29 millimeters. Even more preferably, the length of the device cavity is about 27 millimeters or about 28 millimeters.

[0110] The diameter of the device cavity may be from about 4 millimeters to about 10 millimeters. The diameter of the device cavity may be from about 5 millimeters to about 9 millimeters. The diameter of the device cavity may be from about 6 millimeters to about 8 millimeters. The diameter of the device cavity may be from about 6 millimeters to about 7.5 millimeters.

[0111] The diameter of the device cavity may be substantially the same as, or larger than, the diameter of the aerosol-generating article. The diameter of the device cavity may be the same as the diameter of the aerosol-generating article in order to establish a tight fit with the aerosol-generating article.

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

[0113] Such an airtight fit may establish an airtight fit or configuration between the device cavity and the aerosol-generating article received therein. In such an airtight configuration, there will be substantially no gap or empty space between the peripheral wall defining the device cavity and the aerosol-generating article through which air can pass and flow. 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 comprise an air intake channel extending between a channel inlet and a channel outlet. The air intake channel may be configured to establish a fluid communication between the interior of the device cavity and the exterior of the aerosol generating device. The air intake channel of the aerosol generating device may be defined within the housing of the aerosol generating device to enable fluid communication between the interior of the device cavity and the exterior of the aerosol generating device. When an aerosol generating article is received within the device cavity, the air intake channel may be configured to provide an airflow into the article to deliver the generated aerosol to a user who aspirates from the mouth-side end of the article.

[0115] The air intake channel of the aerosol generating device may be defined within the peripheral wall of the housing of the aerosol generating device, or by the peripheral wall. In other words, the air intake channel of the aerosol generating device may be defined within the thickness of the peripheral wall, or by the inner surface of the peripheral wall, or by a combination of both. The air intake channel may be partially defined by the inner surface of the peripheral wall and may be partially defined within the thickness of the peripheral wall. The inner surface of the peripheral wall defines the periphery of the device cavity.

[0116] The air intake channel of the aerosol generating device may extend from an inlet located at the mouth-side end or proximal end of the aerosol generating device to an outlet located away from the mouth-side end of the device. The air intake channel may extend along a direction parallel to the longitudinal axis of the aerosol generating device.

[0117] The heating chamber or device cavity may be sized such that a longitudinal gap is provided between the aerosol-generating article received therein and the peripheral wall defining the device cavity. Such a longitudinal gap may partially or completely surround the aerosol-generating article received within the device. Such a longitudinal gap or space may define an air intake channel extending from the open mouth side end of the device cavity to the closed distal end of the device cavity. Further, the device housing may be configured such that air can enter the upstream end of the article when the upstream end of the article abuts the distal end of the device cavity. The device housing and cavity may preferably establish fluid communication between the air intake channel of the device and the upstream end of the received aerosol-generating article at the distal end of the device cavity. As a result, when the inserted aerosol-generating article is puffed, air enters the aerosol-generating device through the air intake channel, flows towards the distal end of the device cavity, and can enter the upstream end of the received article.

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

[0119] The heating element of such an aerosol-generating device may be in any suitable form for conducting heat. Heating of the aerosol-generating substrate may be achieved from the inside, from the outside, or both. The heating element may be a heater blade or pin adapted to be inserted into the substrate such that the aerosol-generating substrate is heated from the inside. Preferably, the heating element may partially or completely surround the substrate and circumferentially heat the substrate from the outside.

[0120] Preferably, the heater may externally heat the aerosol-generating article when received within the aerosol-generating device. Such an external heater may surround or enclose the aerosol-generating article when inserted or received within the aerosol-generating device. The length of the heater preferably substantially corresponds to the length of the aerosol-generating substrate of the aerosol-generating article configured to be received by the aerosol-generating device.

[0121] The heater can be arranged to heat the outer surface of the aerosol generation substrate. The heater can be arranged to be inserted into the aerosol generation substrate when the aerosol generation substrate is received within the cavity. The heater may be positioned within the device cavity or the heating chamber.

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

[0123] The heater may include an induction heating arrangement. The induction heating arrangement includes an induction source and a susceptor, which may be provided external to or within the aerosol generation substrate. The induction source may include an inductor coil and a power source configured to provide a high-frequency oscillating current to the inductor coil. As used herein, a high-frequency oscillating current means an oscillating current having a frequency of about 500 kHz to about 30 MHz. Advantageously, the heater may comprise a DC / AC inverter for converting a DC current supplied by a DC power source into an alternating current. The inductor coil can be arranged to generate a high-frequency oscillating electromagnetic field when receiving a high-frequency oscillating current from the power source. The inductor coil can be arranged to generate a high-frequency oscillating electromagnetic field within the device cavity. The inductor coil may substantially surround the device cavity. The inductor coil may 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 that includes a material having the ability to convert electromagnetic energy into heat. When the susceptor element is located within an alternating electromagnetic field, the susceptor is heated. The heating of the susceptor element can be the result of at least one of the hysteresis losses and eddy currents induced within the susceptor, depending on the electrical and magnetic properties of the susceptor material.

[0125] The susceptor element can be arranged such that when the aerosol generating article is received within the cavity of the aerosol generating device, the oscillating electromagnetic field generated by the inductor coil induces a current within the susceptor element and heats the susceptor element. The aerosol generating device preferably has the ability to generate a varying electromagnetic field having a magnetic field strength (strength of the H field) of 1 to 5 kiloamperes per meter (kA / m), preferably 2 to 3 kA / m, for example about 2.5 kA / m. The electrically operating aerosol generating device preferably has the ability to generate a varying electromagnetic field having a frequency of 1 to 30 MHz, for example, 1 to 10 MHz, for example, 5 to 7 MHz.

[0126] The susceptor element may be located in contact with the aerosol generating substrate. The susceptor element may be located within the aerosol generating device. The susceptor element may be arranged around the periphery of the device cavity. The aerosol generating device may include only one susceptor element. The aerosol generating device may comprise a plurality of susceptor elements. The susceptor element is preferably arranged to heat the exterior of the aerosol generating substrate. The susceptor element may surround the aerosol generating article when received within the heating chamber.

[0127] The susceptor element can comprise any suitable material. The susceptor element can be formed from any material that can be inductively heated to a temperature sufficient to release volatile compounds from the aerosol generating substrate. Suitable materials for an elongate susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium, and composites of metallic materials. Some susceptor elements contain metal or carbon. Advantageously, the susceptor element can comprise or consist of a ferromagnetic alloy such as, for example, ferromagnetic iron, ferromagnetic steel or stainless steel, ferromagnetic particles, and ferromagnetic materials such as ferrite. A suitable susceptor element is or can include aluminum. The susceptor element preferably contains more than about 5 percent of a ferromagnetic or paramagnetic material, more preferably more than 20 percent of a ferromagnetic or paramagnetic material, and even more preferably more than 50 percent or more than 90 percent of a ferromagnetic or paramagnetic material. Some elongate susceptor elements can be heated to a temperature exceeding 250 degrees Celsius.

[0128] The susceptor element can comprise a non-metallic core having a metal layer arranged thereon. For example, the susceptor element can include metal tracks formed on the outer surface of a ceramic core or substrate.

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

[0130] In use, the heater can be controlled to operate within a defined operating temperature range below the maximum operating temperature. The operating temperature range within the heating chamber (or device cavity) is preferably from about 150 degrees Celsius to about 300 degrees Celsius. The operating temperature range of the heater can be from about 150 degrees Celsius to 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. Specifically, as described in the present disclosure, when using an aerosol generating article having a relatively low RTD (e.g., having an RTD in the downstream section of less than 15 millimeters H2O) and using an aerosol generating device with an external heater having an operating temperature range of about 180 degrees Celsius to about 200 degrees Celsius, it has been found that optimal and consistent aerosol delivery can be achieved.

[0132] As described above, the hollow tubular substrate element of the aerosol generating article according to the present disclosure can advantageously be adapted such that its length substantially matches the longitudinal dimension of the heating element of the aerosol generation system intended to be used to heat the aerosol generating article. Thereby, the hollow tubular substrate element may be reliably heated substantially along its entire length, and as a result, the generation of aerosol from the aerosol generating substrate can be maximized.

[0133] The aerosol generating device may comprise a power source. The power source may be a DC power source. In some embodiments, the power source is a battery. The power source may be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery (e.g., a lithium cobalt, lithium iron phosphate, or lithium polymer battery). However, in some embodiments, the power source may be another form of charge storage device such as a capacitor. The power source may be required to be rechargeable and may have a capacity that allows for the accumulation of sufficient energy for one or more user operations, such as one or more experiences of aerosol generation. For example, the power source may have a capacity sufficient to enable continuous heating of the aerosol generating substrate for about six minutes, or a multiple of six minutes, corresponding to the typical time taken to smoke a conventional cigarette. In another example, the power source may have a capacity sufficient to enable a predetermined number of smoking sessions or discontinuous activation of the heater.

[0134] As described above, the aerosol generating device comprises a device cavity or an airflow guiding element extending along the heating chamber. The airflow guiding element preferably extends along the central longitudinal axis direction 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 the open upstream end of the aerosol generating substrate of the aerosol generating article. Such an open upstream end may be defined by the upstream end of the upstream section of the aerosol generating article. For example, a hollow tubular element or a hollow tubular aerosol generating substrate of the upstream section may define an open upstream end of the article. Further, the hollow tubular substrate and, if present, the hollow tubular upstream element define a longitudinally extending cavity arranged to receive the airflow guiding element after insertion of the aerosol generating article 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 guiding element preferably extends longitudinally within the longitudinally extending substrate cavity. A primary airflow path or channel may be defined between the outer surface of the airflow guiding element and the inner surface of the aerosol generating substrate. Thus, the width or diameter of a portion of the airflow guiding element may be smaller than the diameter of the substrate cavity.

[0137] The airflow guiding element may extend longitudinally into the heating chamber from the device housing. The airflow guiding element may extend longitudinally from a portion of the device housing that defines the distal end of the heating chamber. The airflow guiding element preferably extends longitudinally towards the mouth-side end of the heating chamber. The airflow guiding element preferably extends longitudinally substantially parallel to the central axis of the heating chamber. The airflow guiding element preferably extends longitudinally substantially aligned with the central axis of the heating chamber.

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

[0139] The aerosol generating device may comprise a base support element from which an airflow guiding element may extend. The base support element may be connected to the 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 maximum 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 segment of the upstream section.

[0141] The base support element may have a disc shape or a plate shape, and is preferably cylindrical. The base support element is preferably porous or comprises at least one opening. Thereby, fluid communication is established between the outside of the aerosol generating article and the inside of the aerosol generating substrate through the base support element. The periphery of the base support element may be chamfered. This may facilitate the engagement between the base support element and the hollow upstream end of the aerosol generating article after insertion into the device cavity. The chamfered peripheral portion of the base support element may function as a centering guide for the article inserted into the aerosol generating device, ensuring that the inserted article is centered around the central longitudinal axis of the device cavity.

[0142] The airflow guiding element preferably comprises an elongated body extending in the longitudinal direction within the heating chamber. The airflow guiding element preferably comprises an elongated body extending from the upstream proximal end of the airflow guiding element to the downstream distal end of the airflow guiding element. The airflow guiding element preferably comprises an elongated body extending from the fixed end of the airflow guiding element to the free end of the airflow guiding element. The downstream end or distal end of the airflow guiding 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 guiding element.

[0143] The upstream end of the airflow guiding element may be connected to the base support element. The central longitudinal axis of the airflow guiding element may be aligned with the central longitudinal axis of the base support element. The airflow guiding element preferably comprises an elongated body extending from the fixed end of the airflow guiding element to the free end of the airflow guiding element. The end of the airflow guiding element connected to the base support element may define the fixed end of the airflow guiding element, while the opposite end may be the free end of the airflow guiding 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 at most about 5 mm. The length of the base support element may be at most about 4 mm. The length of the base support element may be at most about 3 mm.

[0146] The elongated body of the airflow guiding element may be rod-shaped or conical-shaped. The elongated body of the airflow guiding element preferably comprises a hollow body or a tube defining an empty cavity in the longitudinal axis direction. The elongated body of the airflow guiding element preferably comprises a hollow cylindrical tube defining an empty cavity in the longitudinal axis direction.

[0147] The downstream end of the hollow body may be closed so that air does not flow into the base cavity through the interior of the hollow body.

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

[0149] The downstream end of the hollow body may be porous so that fluid communication is established between the interior of the hollow body and the base cavity and a secondary airflow path into the base cavity is defined, or one or more perforations, openings, inlets, or outlets may be provided.

[0150] The downstream end of the hollow body may be open such that fluid communication is established between the interior of the hollow body and the base cavity, and a secondary airflow path within the airflow guiding element is defined. The secondary airflow path may direct air directly to the downstream section of the article if the airflow guiding element extends over the entire length of the base cavity. The secondary airflow path may direct air into the base cavity of the article if the airflow guiding element extends along less than 100 percent of the length of the base cavity.

[0151] The upstream end of the hollow body may also be open. The base support element is preferably porous or preferably includes at least one opening such that fluid communication is established between the exterior of the aerosol generating article and the interior of the aerosol generating base through the base support element. The base support element may include a central opening aligned with the open upstream end of the airflow guiding element. This allows air to flow through the base support element into the base cavity via a central secondary airflow path defined within the airflow guiding element. The primary airflow path or channel may be defined between the inner surface of the aerosol generating base and the outer surface of the airflow guiding element. In other words, the primary airflow path or channel may surround the airflow guiding element.

[0152] When the airflow guiding element includes a hollow body, perforations or holes may be provided that extend through the peripheral wall of the hollow body defining an empty cavity in the longitudinal axis direction. The peripheral wall of the hollow body may be porous. One or more such peripheral perforations may follow a specific path along or around the hollow body of the airflow guiding element. One or more such peripheral perforations may follow a linear, helical, curved, or wavy path along or around the hollow body of the airflow guiding element. This advantageously enables the establishment of fluid communication between the interior of the hollow body and the base cavity such that one or more secondary airflow paths into the base cavity are defined. Air may flow through the base support element into the hollow body or tube of the airflow guiding element and out through the peripheral wall of the hollow body into the base cavity. Air moving through the hollow body may also exit into the base cavity via an opening at the downstream end of the hollow body. Such secondary airflow may provide a dilution and cooling function to the primary airflow moving downstream between the airflow guiding element and the inner surface of the aerosol generating element.

[0153] The width or diameter of the airflow guiding element may be uniform along its length. The width or diameter of the airflow guiding element may vary along its length. The inner diameter of the airflow guiding element may be at least about 0.5 mm. The inner diameter of the airflow guiding element may be at least about 1 mm. The inner diameter of the airflow guiding element may be at least about 1.5 mm. The inner diameter of the airflow guiding element may be at least about 2 mm. The inner diameter of the airflow guiding element may be at most about 5 mm. The inner diameter of the airflow guiding element may be at most about 4 mm. The size of the hollow cavity defined within the airflow guiding element defines the size of the secondary airflow channel or path and the amount of dilution or cooling air arranged to enter the base cavity during use.

[0154] The airflow guiding element may be textured. The airflow guiding element may have a non-uniform outer surface or a raised outer surface. The airflow guiding element may include raised elements on its outer surface. The airflow guiding element may include one or more grooves, depressions, protrusions, projections, ridges, or bulges provided on its outer surface. By having a textured or non-uniform outer surface, the airflow guiding element has the ability to disrupt the air flowing around it so as to form local turbulence, which can enhance the mixing of air with the aerosol-forming components released.

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

[0156] The airflow guiding element may include a core elongated portion by the aforementioned elongated body and at least one extension portion located along the core portion. The at least one extension portion may include a protrusion, projection, or bulge provided on the outer surface of the core portion. The at least one extension portion may be formed on the outer surface of the core portion. The at least one extension portion may define a raised surface on the airflow guiding element, preferably on its core portion. The at least one extension portion may extend outward from the core portion (i.e., away from the central axis of the core portion). The at least one extension portion may extend radially from the core portion. The at least one extension portion may extend along the major axis direction along the core portion. The at least one extension portion may extend completely or partially circumferentially around the core portion.

[0157] The airflow guiding element may include at least two extension portions located along the core portion. Each extension portion may be located at its respective major axis direction or axial position along the core portion. The airflow guiding element may include three extension portions located along the core portion.

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

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

[0160] The length of each or the extension portions of the airflow guiding element may be at most about 75 percent of the total length of the airflow guiding element. The length of each or the extension portions of the airflow guiding element may be at most about 60 percent of the total length of the airflow guiding element. The length of each or the extension portions of the airflow guiding element may be at most about 50 percent of the total length of the airflow guiding element. The length of each or the extension portions of the airflow guiding element may be at most about 40 percent of the total length of the airflow guiding element. The length of each or the extension portions of the airflow guiding element may be at most about 35 percent of the total length of the airflow guiding element.

[0161] When a plurality of extension portions are provided, each extension portion may have a different length. For example, the airflow guiding element may include three extension portions disposed continuously along the core portion, the first extension portion may extend along approximately 15 percent of the total length of the airflow guiding element, and the other two extension portions may extend along approximately 35 percent of the total length of the airflow guiding element.

[0162] Advantageously, the amount of turbulence and eddy currents created in the air flowing around the airflow guiding element can be adjusted according to the size of the extension portion with respect to the airflow guiding element, the position of one or each extension portion along the airflow guiding element, and the distance between successive or adjacent extension portions.

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

[0164] Successive or adjacent extension portions may be spaced apart from each other so as to define a gap therebetween. The extension portions may be evenly spaced apart from each other. Providing a gap between successive or adjacent extension portions defines a section of the primary airflow channel with an increased cross-sectional area, which allows for a local deceleration of the air after flowing over the upstream extension portion or after flowing over the downstream extension portion, mainly when the cross-section of the extension portion is uniform along its length, such as cylindrical or ring-shaped. The outer surface of the core portion may be exposed by such gaps.

[0165] The base support element and the airflow guiding element may be manufactured separately before the assembly of the aerosol generating device and then connected to each other. The base support element and the airflow guiding element may be integrally formed with each other, for example, by extrusion or by injection molding. Similarly, the core part of the airflow guiding element and any extension part may be manufactured separately before the assembly of the aerosol generating device and then connected to each other. The core part of the airflow guiding element and any extension part may be integrally formed with each other, for example, by extrusion or by injection molding. The extension part may be manufactured separately from the core part and then assembled onto the core part. For example, the extension part may be a ring-shaped or cylindrical element that is attached onto the core part and connected to the core part. For example, such a ring-shaped or cylindrical element may slide onto the core part and engage with the core part by adhesion or interference fit. An airflow guiding element structure that is substantially structurally resistant to deformation is preferred for use in an aerosol generating device for its intended repeated use by insertion and removal of the aerosol generating article.

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

[0167] The airflow guiding element, the base support element, or both may include 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 guiding element may comprise an outer layer or coating provided at least partially on an external surface, preferably the external surface of the airflow guiding element body. The outer layer or coating may include one or more of an aerosol former, a flavorant, and a further aerosol generating substrate. Such aerosol formers, flavorants, and further aerosol generating substrates of the outer layer or coating may each be in accordance with the aerosol formers, flavorants, and aerosol generating substrates described in the present disclosure.

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

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

[0171] The length of the airflow guiding element may be at most about 30 mm. The length of the airflow guiding element may be at most about 25 mm. The length of the airflow guiding element may be at most about 20 mm. The length of the airflow guiding element may be at most about 15 mm. The length of the airflow guiding element may be at most about 12 mm. The length of the airflow guiding element may be at most about 10 mm.

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

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

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

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

[0176] The length of the airflow guiding element defines the length of a restricted airflow path or channel defined between the outer surface of the airflow guiding element and the inner surface of the aerosol generating substrate. It can be realized that a balance can be achieved between providing a relatively long airflow guiding element so as to define a relatively long restricted airflow path and the manufacturing cost of providing such a long airflow guiding element. Ideally, the length of the airflow guiding element may be at least about 50 percent of the length of the aerosol generating substrate or the substrate cavity, and preferably at least about 60 percent.

[0177] Preferably, the central axis or the longitudinal axis direction of the airflow guiding element is aligned with the center or the longitudinal axis direction of the aerosol generating substrate. The airflow guiding element is preferably axially symmetric. This may ensure that the restricted airflow channel defined around the airflow guiding element and between the airflow guiding element and the inner surface of the aerosol generating substrate is axially symmetric.

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

[0179] When the outer diameter or width of the airflow guiding element changes, a portion of the airflow guiding element having an outer diameter or width corresponding to the maximum width or outer diameter of the airflow guiding element is preferably located 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 reduction in the cross-sectional area of the airflow channel defined between the outer surface of the airflow guiding element and the inner surface of the aerosol generating substrate received within the device cavity of the aerosol generating device, and as a result of the increase in the diameter of the airflow guiding element, it further progresses along the airflow guiding element and is not present at the base (or upstream end or proximal end) of the airflow guiding element. This increase in diameter or width obstructs the airflow, pushes the air closer to the inner surface of the aerosol generating substrate, thereby promoting local turbulent airflow and local airflow acceleration so as to form between the airflow guiding element and the inner surface of the aerosol generating substrate, particularly at the location where the diameter or width increases. This can improve aerosol generation as a result of enhanced mixing of the air with the aerosol-forming components released from the heated aerosol generating substrate.

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

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

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

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

[0184] The maximum outer diameter or width of the airflow guiding element may be at least about 25 percent of the inner diameter of the aerosol generating substrate, or the diameter of the substrate cavity. The maximum outer diameter or width of the airflow guiding element may be at least about 40 percent of the inner diameter of the aerosol generating substrate, or the diameter of the substrate cavity. The maximum outer diameter or width of the airflow guiding element may be at least about 50 percent of the inner diameter of the aerosol generating substrate, or the diameter of the substrate cavity. The maximum outer diameter or width of the airflow guiding element may be at least about 60 percent of the inner diameter of the aerosol generating substrate, or the diameter of the substrate cavity. The maximum outer diameter or width of the airflow guiding element may be at least about 75 percent of the inner diameter of the aerosol generating substrate, or the diameter of the substrate cavity.

[0185] A portion of the airflow guiding element having a diameter corresponding to the maximum outer diameter or width of the airflow guiding element is preferably located away from (or downstream of) the base or upstream end of the airflow guiding element. A portion of the airflow guiding element having a diameter corresponding to the maximum outer diameter or width of the airflow guiding element is preferably located away from (or downstream of) the base or upstream end of the airflow guiding element and at least about 10 percent of the length of the airflow guiding element. A portion of the airflow guiding element having a diameter corresponding to the maximum outer diameter or width of the airflow guiding element is preferably located away from (or downstream of) the base or upstream end of the airflow guiding element and at least about 20 percent of the length of the airflow guiding element. A portion of the airflow guiding element having a diameter corresponding to the maximum outer diameter or width of the airflow guiding element is preferably located away from (or downstream of) the base or upstream end of the airflow guiding element and at least about 25 percent of the length of the airflow guiding element. A portion of the airflow guiding element having a diameter corresponding to the maximum outer diameter or width of the airflow guiding element is preferably located away from (or downstream of) the base or upstream end of the airflow guiding element and at least about 50 percent of the length of the airflow guiding element.

[0186] The diameter of the portion of the airflow guiding element upstream of the portion of the airflow guiding element having a diameter corresponding to the maximum outer diameter or width of the airflow guiding element is preferably less than (or not exceeding) the maximum outer diameter or width of the airflow guiding element.

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

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

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

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

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

[0192] The minimum outer diameter or width of the airflow guiding element may be at least about 10 percent of the inner diameter of the aerosol generating substrate or the diameter of the substrate cavity. The minimum outer diameter or width of the airflow guiding element may be at least about 20 percent of the inner diameter of the aerosol generating substrate or the diameter of the substrate cavity. The minimum outer diameter or width of the airflow guiding element may be at least about 25 percent of the inner diameter of the aerosol generating substrate or the diameter of the substrate cavity. The minimum outer diameter or width of the airflow guiding element may be at least about 40 percent of the inner diameter of the aerosol generating substrate or the diameter of the substrate cavity. The minimum outer diameter or width of the airflow guiding element may be at least about 50 percent of the inner diameter of the aerosol generating substrate or the diameter of the substrate cavity. The minimum outer diameter or width of the airflow guiding element may be at least about 60 percent of the inner diameter of the aerosol generating substrate or the diameter of the substrate cavity.

[0193] The maximum outer diameter or width of the airflow guiding element may be about 100 percent of the inner diameter of the aerosol generating substrate or the diameter of the substrate cavity. Thus, a portion of the airflow guiding element may contact the aerosol generating substrate. A portion of the extension or protrusion of the airflow guiding element may contact the aerosol generating substrate. Sizing the airflow guiding element to contact the aerosol generating substrate may facilitate positioning the airflow guiding element at the center of the substrate cavity and may assist in holding the airflow guiding element within the substrate cavity.

[0194] The airflow guiding element may extend along the central axis of the device cavity. The airflow guiding element may extend along the central axis of the substrate cavity. A gap or space in the longitudinal direction may be defined between the outer surface of the airflow guiding element and the peripheral wall of the device that defines the heating chamber.

[0195] When an article is received with the heating chamber, a longitudinal gap or space may be defined between the outer surface of the airflow guiding element and the inner circumferential surface of the aerosol generating substrate. The outer surface of the airflow guiding element or a portion thereof may be spaced from the inner surface of the substrate cavity such that an airflow channel is defined between the outer surface of the airflow guiding element and the inner surface of the aerosol generating substrate. Such a defined airflow channel is preferably referred to as a primary airflow channel or a restricted airflow channel.

[0196] The airflow channel is preferably of annular shape. In other words, the gap or space between the airflow guiding 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 guiding element and the inner surface of the aerosol generating substrate may define the height or thickness of the primary airflow channel or the restricted airflow channel. Depending on the local diameter or width of the airflow guiding element at a particular longitudinal and circumferential position along its elongated body, the height or thickness of the airflow channel may vary in the longitudinal direction or the circumferential direction or both.

[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 may be at least about 0 mm. In other words, a portion of the airflow guiding element may contact the aerosol generating substrate such that there is no distance or gap between such a portion of the airflow guiding element and the aerosol generating substrate. The minimum thickness of the airflow channel may be at least about 0.25 mm. The minimum thickness of the airflow channel may be at least about 0.5 mm. The minimum thickness of the airflow channel may be at least about 1.5 mm. As described herein, when an aerosol generating article is received within the heating chamber of the device, the airflow guiding element extends axially within the substrate cavity. In other words, the airflow guiding element is received within the aerosol generating substrate of the aerosol generating article. The airflow guiding element may not contact the inner surface of the aerosol generating substrate. Along its entire length, the airflow guiding element may not contact the inner surface of the aerosol generating substrate. In other words, no portion of the outer surface of the airflow guiding element contacts the inner surface of the aerosol generating substrate. This allows for a thicker and less obstructed definition of the airflow channel, thereby allowing more airflow to move between the inner surface of the aerosol generating substrate and the airflow guiding element.

[0200] The maximum thickness of the airflow channel may be up to about 6 mm. The maximum thickness of the airflow channel may be up to about 5 mm. The maximum thickness of the airflow channel may be up to about 3 mm. The maximum thickness of the airflow channel may 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 guiding 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 and maximum thicknesses of the airflow channel are effectively equal.

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

[0204] In the aerosol generating article of the present disclosure, an aerosol generating substrate including 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. The downstream section of the aerosol generating article preferably extends between the aerosol generating substrate and the downstream end of the aerosol generating article. The downstream section may comprise one or more elements, each of which is described in more detail within the present disclosure.

[0205] The downstream section preferably comprises at least one hollow tubular element. The hollow tubular element may be adjacent to the downstream end of the rod of the aerosol generating substrate. The hollow tubular element may be installed immediately downstream of the aerosol generating substrate. In other words, the hollow tubular element may abut against the downstream end of the aerosol generating substrate. By this arrangement, the airflow from the longitudinal axis airflow channel of the hollow tubular substrate element into the downstream section and the flow of aerosol through the aerosol generating article may be optimized.

[0206] The downstream section of the aerosol generating article preferably 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 a hollow tubular downstream element.

[0208] In the context of the present disclosure, the hollow tubular element of the downstream section provides an unrestricted flow channel through the airflow path. This means that the hollow tubular element provides a negligible level of draw resistance (RTD) as defined above. Thus, the airflow path should not include any components that would impede the longitudinal airflow. Preferably, the airflow path is substantially empty.

[0209] The hollow tubular element of the downstream section provides an empty cavity downstream of the aerosol generating substrate, whereby the cooling and nucleation of the aerosol particles generated by the aerosol generating substrate may be improved. Thus, the hollow tubular element of the downstream section may function as an aerosol cooling element.

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

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

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

[0213] A relatively long hollow tubular element provides and defines a relatively long internal cavity within the downstream section of the aerosol generating article. By providing a relatively long cavity, the above-described advantages of nucleation may be maximized, thereby improving aerosol formation and cooling.

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

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

[0216] For example, the ratio of the length of the hollow tubular substrate element to the length of the hollow tubular element of the downstream section may be from about 0.2 to about 1.25, or from about 0.25 to about 1, or from about 0.3 to about 0.75.

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

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

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

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

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

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

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

[0224] The wall thickness of the hollow tubular element in the downstream section may be about 2 millimeters or less, preferably about 1.5 millimeters or less, and even more preferably about 1.25 mm or less. The wall thickness of the hollow tubular element in the downstream section may be about 1 millimeter or less. The wall thickness of the hollow tubular element in the downstream section may be about 500 micrometers or less.

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

[0226] By keeping the wall thickness of the hollow tubular segment of the downstream section relatively small, the overall internal volume of the hollow tubular element (which is made available for the aerosol to initiate the nucleation process as soon as the aerosol component leaves the aerosol generating substrate) and the cross-sectional surface area of the cavity of the hollow tubular element are effectively maximized, while at the same time ensuring that the hollow tubular element has the structural strength necessary not only to prevent the disintegration of the aerosol generating article but also to provide some support to the rod of the aerosol generating substrate, and that the RTD of the hollow tubular element is minimized. A larger value of the cross-sectional surface area of the cavity of the hollow tubular element is understood to be associated with a reduced velocity of the aerosol flow along the aerosol generating article, which is also expected to be advantageous for aerosol nucleation. Furthermore, by utilizing a hollow tubular element with a relatively small thickness, it may be possible to substantially prevent the diffusion of the ventilation air before it comes into contact with and mixes with the aerosol flow, which is also understood to be more advantageous for the nucleation phenomenon. In fact, by providing a more controllably localized cooling of the flow of the volatile species, it may be possible to enhance the cooling effect on the formation of new aerosol particles.

[0227] The hollow tubular element of the downstream section preferably has an outer diameter substantially 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 larger 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 of 5 millimeters to 10 millimeters, such as 5.5 millimeters to 9 millimeters, or 6 millimeters to 8 millimeters.

[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 millimeters. For example, the hollow tubular element may have an inner diameter of at least about 2.5 millimeters, at least about 3 millimeters, or at least about 3.5 millimeters. By installing a hollow tubular element having an inner diameter as presented above, advantageously, sufficient rigidity and strength can be provided to the hollow tubular element.

[0231] The hollow tubular element of the downstream section may have an inner diameter of about 10 millimeters or less. For example, the hollow tubular element may have an inner diameter of about 9 millimeters or less, about 8 millimeters or less, or about 7.5 millimeters or less. By providing a hollow tubular element having an inner diameter as described above, the pulling resistance of the hollow tubular segment can be advantageously reduced.

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

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

[0234] Particularly preferably, the inner diameter of the hollow tubular base 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 substrate element of the aerosol generating substrate is preferably alignable with the central longitudinal axis of the hollow tubular element of the downstream section. For example, the inner diameter of the hollow tubular substrate element is substantially equal to the inner diameter of the hollow tubular element of the downstream section, and the central longitudinal axis of the hollow tubular substrate element may be aligned with the central longitudinal axis of the hollow tubular element of the downstream section such that the cavities of the hollow tubular substrate element and the hollow tubular element of the downstream section can 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 layer of paper. The paper can be very stiff paper. The paper can be crimped paper such as heat-resistant crimped paper or crimped sulfate paper.

[0237] Preferably, the hollow tubular element may comprise cardboard. The hollow tubular element can be a cardboard tube. The hollow tubular element can be formed from cardboard. Advantageously, cardboard provides a balance between being deformable to facilitate the insertion of articles into the aerosol generating device and being sufficiently rigid to provide proper engagement of the aerosol generating 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 from spirally wound paper. The hollow tubular element can be formed from a plurality of layers of paper. The paper can have a basis weight of 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 comprise a polymeric material. For example, the hollow tubular element may comprise a polymeric film. The polymeric film may comprise a cellulose film. The hollow tubular segment may comprise low density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. The hollow tubular element may comprise cellulose acetate tow.

[0240] When the hollow tubular element comprises cellulose acetate tow, the cellulose acetate tow may have from about 2 to about 4 denier per filament and from about 25 to about 40 total denier.

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

[0242] Preferably, the aerosol generating article according to the present disclosure may comprise a ventilation zone at a position along the downstream section. More particularly, when the downstream section comprises a hollow tubular element, the ventilation zone may be provided at a position along the hollow tubular element.

[0243] Thus, a vented cavity is provided downstream of the rod of the aerosol generating substrate. Thereby, particularly efficient cooling of the aerosol may be provided and improvement of nucleation of aerosol particles may be promoted.

[0244] The ventilation zone may typically comprise a plurality of perforations through the peripheral wall of the hollow tubular element. The plurality of perforations of the ventilation zone may pass through a wrapper surrounding the hollow tubular element. The ventilation zone preferably comprises at least one circumferential row of perforations. The ventilation zone may comprise two peripheral rows of perforations. For example, the perforations may be formed online during the manufacture of the aerosol generating article. Preferably, each circumferential row of perforations comprises from 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. The mouthpiece element is preferably located downstream of the hollow tubular element of the downstream section as 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 the aerosol-generating article according to the present disclosure may provide an attractive appearance and feel for the consumer.

[0247] The mouthpiece element may be a mouthpiece filter element. The mouthpiece element may comprise at least one mouthpiece filter segment formed of a fibrous filter material. Parameters or characteristics described with respect to the entire mouthpiece element may equally apply to the mouthpiece filter segments of the mouthpiece element.

[0248] The fibrous filter material may be for filtering the aerosol generated from the aerosol-generating substrate. Suitable fibrous filter materials will be known to those skilled in the art. 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 composed of a single mouthpiece filter segment. The mouthpiece element may include two or more mouthpiece filter segments that are axially aligned in an abutting relationship with their ends abutting each other.

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

[0251] The mouthpiece element may optionally contain a flavorant provided in any suitable form. For example, the mouthpiece element may include one or more capsules, flavorant beads or granules, or one or more flavor-loaded threads or filaments.

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

[0253] Preferably, the mouthpiece element is surrounded by a plug wrap. Preferably, the mouthpiece element is not ventilated so that air does not enter the aerosol-generating article along the mouthpiece element.

[0254] The mouthpiece element preferably has an outer diameter substantially equal to the outer diameter of the aerosol-generating article. The diameter of the mouthpiece element (or the mouthpiece filter segment) may be substantially the same as the outer diameter of the hollow tubular element. As described in the present disclosure, the outer diameter of the hollow tubular element may be about 7.2 mm plus or minus 10 percent.

[0255] The diameter of the mouthpiece element may be from about 5 mm to about 10 mm. The diameter of the mouthpiece element may be from about 5.5 mm to about 9 mm. The diameter of the mouthpiece element may be from about 6 mm to about 8 mm. The diameter of the mouthpiece element may be about 7.2 mm ± 10 percent. The diameter of the mouthpiece element may be about 7.25 mm ± 10 percent.

[0256] Unless otherwise specified, the draw resistance (RTD) of a component or an aerosol-generating article is measured in accordance with ISO 6565-2015. RTD refers to the pressure required to pass air through the entire length of the component. The terms "pressure drop" or "draw resistance" of a component or article may also refer to "resistance to draw".

[0257] The draw resistance (RTD) of the downstream section can be at least about 0 mmH2O. The RTD of the downstream section can be at least about 3 mmH2O. The RTD of the downstream section can be at least about 6 mmH2O.

[0258] The RTD of the downstream section can be about 12 mmH2O or less. The RTD of the downstream section can be about 11 mmH2O or less. The RTD of the downstream section can be about 10 mmH2O or less.

[0259] The draw resistance of the downstream section can be about 0 mmH2O or more and less than about 12 mmH2O. Preferably, the draw resistance of the downstream section can be about 3 mmH2O or more and less than about 12 mmH2O. The draw resistance of the downstream section can be about 0 mmH2O or more and less than about 11 mmH2O. Even more preferably, the draw resistance of the downstream section can be about 3 mmH2O or more and less than about 11 mmH2O. Even more preferably, the draw resistance of the downstream section can be about 6 mmH2O or more and less than about 10 mmH2O. Preferably, the draw resistance of the downstream section can be about 8 mmH2O.

[0260] The draw resistance (RTD) characteristics of the downstream section may be wholly or partly due 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 fully define the RTD of the downstream section.

[0261] The draw resistance (RTD) of the mouthpiece element may be at least about 0 mmH2O. The RTD of the mouthpiece element can be at least about 3 mmH2O. The RTD of the mouthpiece element may be at least about 6 mmH2O.

[0262] The RTD of the mouthpiece element can be about 12 mmH2O or less. The RTD of the mouthpiece element can be about 11 mmH2O or less. The RTD of the mouthpiece element can be about 10 mmH2O or less.

[0263] The draw resistance of the mouthpiece element can be from about 0 mmH2O or more and less than about 12 mmH2O. Preferably, the draw resistance of the mouthpiece element can be from about 3 mmH2O or more and less than about 12 mmH2O. The draw resistance of the mouthpiece element can be from about 0 mmH2O or more and less than about 11 mmH2O. Even more preferably, the draw resistance of the mouthpiece element can be from about 3 mmH2O or more and less than about 11 mmH2O. Even more preferably, the draw resistance of the mouthpiece element can be from about 6 mmH2O or more and less than about 10 mmH2O. Preferably, the draw resistance of the mouthpiece element can be about 8 mmH2O.

[0264] As described above, the mouthpiece element or the mouthpiece filter segment can be formed of a fibrous material. The mouthpiece element can be formed of a porous material. The mouthpiece element can be formed of a biodegradable material. The mouthpiece element can be formed of a cellulose material such as cellulose acetate. For example, the mouthpiece element can be formed from a bundle of cellulose acetate fibers having from about 10 to about 15 denier / filament. For example, the mouthpiece element is formed from a relatively low density cellulose acetate tow, such as a cellulose acetate tow containing fibers of about 12 denier per filament.

[0265] The mouthpiece element can be formed of a polylactic acid-based material. The mouthpiece element can be formed of a biodegradable plastic material, preferably a starch-based biodegradable plastic material. The mouthpiece element can be produced by injection molding or extrusion molding. The biodegradable plastic-based material is advantageous because it can provide a simple and inexpensive structure for the mouthpiece element to have a specific and complex cross-sectional profile with a plurality of relatively large air flow channels extending through the material of the mouthpiece element to provide appropriate RTD characteristics.

[0266] The mouthpiece element can be formed from a sheet of a suitable material that is curled, pleated, assembled, woven, or folded into an element that defines a plurality of channels extending in the longitudinal direction. Such a sheet of suitable material can be formed of paper, cardboard, a polymer such as polylactic acid, or any other cellulosic, paper-based material or biodegradable plastic-based material. The cross-sectional profile of such a mouthpiece element may exhibit randomly oriented channels.

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

[0268] The length of the mouthpiece element can be at least about 1.5 mm. The length of the mouthpiece element can be at least about 2 mm. The length of the mouthpiece element can be about 7 mm or less. The length of the mouthpiece element can be about 4 mm or less. For example, the length of the mouthpiece element can be from about 1.5 mm to about 7 mm. The length of the mouthpiece element can be from about 2 mm to about 4 mm.

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

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

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

[0272] The ratio of the length of the mouthpiece element to the total length of the aerosol generating article can be about 0.20 or less. Preferably, the ratio of the length of the mouthpiece element to the total length of the aerosol generating article can be about 0.15 or less. More preferably, the ratio of the length of the mouthpiece element to the total length of the aerosol generating article can be about 0.1 or less.

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

[0274] For example, the ratio of the length of the mouthpiece element to the total length of the aerosol generating article is about 0.01 to about 0.2, preferably about 0.02 to about 0.15, and more preferably about 0.05 to about 0.1.

[0275] When the downstream section comprises 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 can be at least about 1.5. In other words, the length of the hollow tubular element can be at least about 150% of the length of the mouthpiece. The ratio of the length of the hollow tubular element to the length of the mouthpiece element can be at least about 5. The ratio of the length of the hollow tubular element to the length of the mouthpiece element can be at least about 7.5.

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

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

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

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

[0280] For example, the downstream section can have a total length from about 20 millimeters to about 50 millimeters, more preferably from about 25 millimeters to about 45 millimeters, and even more preferably from about 30 millimeters to about 40 millimeters.

[0281] The ratio of the length of the downstream section to the total length of the aerosol-generating article can be about 0.80 or less. Preferably, the ratio of the length of the downstream section to the total length of the aerosol-generating article can be about 0.75 or less. More preferably, the ratio of the length of the downstream section to the total length of the aerosol-generating article can be about 0.70 or less. Even more preferably, the ratio of the length of the downstream section to the total length of the aerosol-generating article can be about 0.65 or less.

[0282] The ratio of the length of the downstream section to the total length of the aerosol-generating article can be at least about 0.30. Preferably, the ratio of the length of the downstream section to the total length of the aerosol-generating article can be at least about 0.40. More preferably, the ratio of the length of the downstream section to the total length of the aerosol-generating article can be at least about 0.50. Even more preferably, the ratio of the length of the downstream section to the total length of the aerosol-generating article can 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 millimeters. More preferably, the total length of the aerosol-generating article according to the present invention is at least about 40 millimeters. Even more preferably, the total length of the aerosol-generating article according to the present invention is at least about 45 millimeters. Even more preferably, the total length of the aerosol-generating article according to the present invention is at least about 50 millimeters.

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

[0285] For example, the overall length of the aerosol-generating article may be from about 35 millimeters to about 110 millimeters, or from about 40 millimeters to about 100 millimeters, or from about 45 millimeters to about 75 millimeters, or from about 50 millimeters to about 70 millimeters.

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

[0287] The aerosol-generating article preferably has an outer diameter of about 10 millimeters or less. More preferably, the aerosol-generating article has an outer diameter of about 9 millimeters or less. Even more preferably, the aerosol-generating article has an outer diameter of about 8 millimeters or less.

[0288] For example, the aerosol-generating article can have an outer diameter from about 5 millimeters to about 10 millimeters, or from about 5.5 millimeters to about 9 millimeters, or from about 6 millimeters to about 8 millimeters.

[0289] The outer diameter of the aerosol-generating article can be substantially constant over the overall length of the article. Alternatively, different portions of the aerosol-generating article can have different outer diameters.

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

[0291] The aerosol-generating substrate and the downstream section are preferably combined together with a wrapper such as a tipping wrapper.

[0292] The components of the aerosol-generating article according to the present disclosure are preferably made from biodegradable materials.

[0293] The following provides a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more of the features of another example, or embodiment, or aspect described herein.

[0294] Example 1. An aerosol generating device having an oral end for receiving an aerosol generating article, the aerosol generating device comprising an aerosol generating device comprising a heating chamber for receiving an aerosol generating article at the oral end of the device.

[0295] Example 2. The aerosol generating device according to Example 1, further comprising an airflow guiding element located within the heating chamber and extending in the longitudinal direction towards the oral end of the device, the airflow guiding element being configured to be inserted into the aerosol generating article when received within the heating chamber.

[0296] Example 3. The aerosol generating device according to Example 1 or Example 2, further comprising a heating element provided at or near the periphery of the heating chamber for heating the aerosol generating article received within the heating chamber.

[0297] Example 4. The aerosol generating device according to Example 2, wherein the airflow guiding element is a heating element for heating the aerosol generating article received within the heating chamber.

[0298] Example 5. The aerosol generating device according to Example 2, wherein the airflow guiding element is not a heating element.

[0299] Example 6. The aerosol generating device according to Example 2, wherein the airflow guiding element is or comprises a susceptor element configured to generate heat when placed in an oscillating electromagnetic field.

[0300] Example 7. An aerosol generator according to any one of Examples 1 to 6, wherein the width or outer diameter of the airflow guiding element varies along its length, the first part of the airflow guiding element has a width or outer diameter corresponding to the maximum width or outer diameter of the airflow guiding element, and the second part of the airflow guiding element located upstream of the first part has a width or outer diameter smaller than the maximum width or outer diameter of the airflow guiding element.

[0301] Example 8. An aerosol generator according to any one of Examples 2 to 7, wherein the width or diameter of the airflow guiding element varies along its length.

[0302] Example 9. An aerosol generator according to any one of Examples 2 to 8, wherein the airflow guiding element extends along at least 25 percent of the length of the heating chamber.

[0303] Example 10. An aerosol generator according to any one of Examples 2 to 9, wherein the airflow guiding element extends along at least 50 percent of the length of the heating chamber.

[0304] Example 11. An aerosol generator according to any one of Examples 2 to 10, wherein the airflow guiding element extends along at least 60 percent of the length of the heating chamber.

[0305] Example 12. An aerosol generator according to any one of Examples 2 to 11, wherein the airflow guiding element includes a central core portion and an extension portion located along the core portion, and the extension portion extends outward from the core portion.

[0306] Example 13. An aerosol generator according to Example 12, wherein the extension portion is substantially shaped in the form of a hemisphere, a sphere, a cylinder, a cone, or a ring.

[0307] Example 14. An aerosol generator according to Example 12 or Example 13, wherein the core portion is substantially shaped in the form of a rod, a tube, or a cone.

[0308] Example 15. The aerosol generator according to any one of Examples 12 to 14, wherein the airflow guiding element includes at least two extension portions located along the core portion.

[0309] Example 16. The aerosol generator according to any one of Examples 12 to 14, wherein the airflow guiding element includes at least two extension portions each located at a different position along the core portion.

[0310] Example 17. The aerosol generator according to any one of Examples 2 to 16, wherein the airflow guiding element includes a hollow tube.

[0311] Example 18. The aerosol generator according to any one of Examples 2 to 17, further comprising a base support element, wherein the airflow guiding element extends from the base support element.

[0312] Example 19. The aerosol generator according to Example 18, wherein the base support element is located at the upstream end of the heating chamber.

[0313] Example 20. The aerosol article according to Example 18 or Example 19, wherein the base support element is porous or includes at least one opening so that fluid communication is established through the base support element.

[0314] Example 21. The aerosol article according to any one of Examples 2 to 20, wherein the airflow guiding element includes an airflow inlet at a first position and an airflow outlet at a second position downstream of the first position such that an airflow path is defined within and along the airflow guiding element.

[0315] Example 22. The aerosol article according to any one of Examples 2 to 21, wherein the maximum width or diameter of a portion of the airflow guiding element extending into the heating chamber is at least about 25 percent of the diameter of the heating chamber.

[0316] Example 23. An aerosol-generating article according to any one of Examples 2 to 22, wherein a maximum width or diameter of a portion of the airflow guiding element extending into the heating chamber is at least about 50 percent of the diameter of the heating chamber.

[0317] Example 24. An aerosol-generating article according to any one of Examples 2 to 23, wherein a maximum width or diameter of a portion of the airflow guiding element extending into the heating chamber is at least about 75 percent of the diameter of the heating chamber.

[0318] Example 25. An aerosol-generating article according to any one of Examples 2 to 24, wherein an outer surface of the airflow guiding element is textured or non-uniform.

[0319] Example 26. An aerosol-generating system comprising an aerosol-generating device according to any one of Examples 1 to 25 and an aerosol-generating article configured to be inserted into the heating chamber of the aerosol-generating device.

[0320] Example 27. An aerosol-generating system comprising an aerosol-generating device according to any one of Examples 2 to 25 and an aerosol-generating article configured to be received within the heating chamber, wherein the aerosol-generating article comprises an aerosol-generating substrate, the aerosol-generating substrate being in the form of a 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, and when the aerosol-generating article is received within the heating chamber of the device, the airflow guiding element extends longitudinally within the substrate cavity.

[0321] Example 28. An aerosol-generating system according to Example 27, wherein a width or diameter of the airflow guiding element is smaller than a diameter of the substrate cavity.

[0322] Example 29. The aerosol generating article further includes an upstream section located upstream of the aerosol generating substrate, and the upstream section includes an upstream element adjacent to the upstream end of the aerosol generating substrate. The aerosol generating system according to Example 27 or Example 28.

[0323] Example 30. The aerosol generating system according to any one of Examples 27 to 29, wherein a part of the airflow guiding element contacts a part of the aerosol generating substrate.

[0324] Example 31. The aerosol generating system according to any one of Examples 27 to 30, wherein a part of the airflow guiding element has a width or diameter substantially corresponding to the diameter of the substrate cavity.

[0325] Example 32. The aerosol generating system according to any one of Examples 27 to 31, wherein the outer major axis direction surface of the airflow guiding element and the inner major axis direction surface of the aerosol generating substrate define an airflow channel.

[0326] Example 33. The upstream element includes a solid plug segment. The aerosol generating system according to Example 29.

[0327] Example 34. The upstream element includes a hollow tubular segment. The aerosol generating system according to Example 29.

[0328] Example 35. The aerosol generating system further includes a downstream section located downstream of the aerosol generating substrate, and the downstream section includes one or more of a mouthpiece element and a hollow tubular element. The aerosol generating system according to any one of Examples 27 to 34.

[0329] Example 36. The aerosol generating article according to Example 27, wherein the mouthpiece element includes at least one mouthpiece filter segment formed from a fibrous filter material.

[0330] Example 37. The aerosol generation substrate has a length of 5 millimeters to 30 millimeters, and the aerosol generation system according to any one of Examples 27 to 36.

[0331] Example 38. The aerosol generation substrate has a length of 5 millimeters to 16 millimeters, and the aerosol generation system according to any one of Examples 27 to 36.

[0332] Example 39. The wall thickness of the aerosol generation substrate is 5 percent to 40 percent of the outer diameter of the aerosol generation substrate, and the aerosol generation system according to any one of Examples 27 to 38.

[0333] Example 40. The wall thickness of the aerosol generation substrate is at least 200 micrometers, and the aerosol generation system according to any one of Examples 27 to 39.

[0334] Example 41. The aerosol generation substrate contains a homogenized tobacco material, and the aerosol generation system according to any one of Examples 27 to 40.

[0335] Example 42. The aerosol generation substrate is formed from a plurality of overlapping sheets of homogenized tobacco material, and the aerosol generation system according to any one of Examples 27 to 41.

[0336] Example 43. The aerosol generation substrate contains one or more aerosol forming substances, and the content of the aerosol forming substances in the aerosol generation substrate is 10 weight percent to 20 weight percent on a dry weight basis, and the aerosol generation system according to any one of Examples 27 to 42.

[0337] Example 44. A part of the airflow guiding element is coated with one or more of a further aerosol generation substrate, a flavorant, and an aerosol forming substance, and the aerosol generation system according to any one of Examples 27 to 43.

[0338] Example 45. An aerosol generation system according to Example 43 or Example 44, wherein the aerosol former comprises one or more of glycerin and propylene glycol.

[0339] Example 46. An aerosol generation system according to any one of Examples 27 to 45, wherein the airflow guiding element extends along at least 25 percent of the length of the substrate cavity.

[0340] Example 47. An aerosol generation system according to any one of Examples 27 to 45, wherein the airflow guiding element extends along at least 50 percent of the length of the substrate cavity.

[0341] Example 48. An aerosol generation system according to any one of Examples 27 to 45, wherein the airflow guiding element extends along at least 60 percent of the length of the substrate cavity.

[0342] Example 49. An aerosol generation system according to any one of Examples 27 to 48, wherein the maximum width or diameter of a portion of the airflow guiding element extending into the substrate cavity is at least about 25 percent of the diameter of the substrate cavity.

[0343] Example 50. An aerosol generation system according to any one of Examples 27 to 48, wherein the maximum width or diameter of a portion of the airflow guiding element extending into the substrate cavity is at least about 50 percent of the diameter of the substrate cavity.

[0344] Example 51. An aerosol generation system according to any one of Examples 27 to 48, wherein the maximum width or diameter of a portion of the airflow guiding element extending into the substrate cavity is at least about 75 percent of the diameter of the substrate cavity.

[0345] Although only by way of illustration, the present invention will be further described with reference to the accompanying drawings.

Brief Description of the Drawings

[0346]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

[0347] FIG. 1 shows the mouth-side end portion of an aerosol generating device 100 configured to receive and heat a corresponding aerosol generating article. In particular, FIG. 1 shows the downstream mouth-side end portion of the aerosol generating device 100 in which a device cavity (or heating chamber) 108 of the device is defined and into which an aerosol generating article can be received. A compatible aerosol generating article may comprise a hollow open distal end and a hollow aerosol generating element.

[0348] The aerosol generating device 100 comprises a housing (or body) 104 extending between a mouth-side 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-side end 102. The mouth-side end of the device cavity 108 is located at the mouth-side end 102 of the aerosol generating device 100. The aerosol generating article is configured to be received through the mouth-side end of the device cavity 108 and held within the device cavity 108.

[0349] 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 the supply of such power 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 heat the aerosol generating substrate 12 of the aerosol generating article from the outside during use.

[0350] The aerosol generating device 100 further comprises an airflow guiding element 20 extending from the closed distal end 103 along the device cavity 108. The airflow guiding element 20 extends along the central longitudinal axis direction of the device cavity 108. The airflow guiding element 20 has a fixed upstream end and a free downstream end.

[0351] The airflow guiding element 20 comprises an irregular outer surface such that the outer diameter of the airflow guiding element 20 varies along its length.

[0352] The airflow guiding 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 guiding element 202 includes three extension portions 23, 27. The first extension portion 27 is located at the fixed end upstream of the airflow guiding element 20 and is hemispherical in shape. The upstream end of the first extension portion 27 is flat and is connected to the distal end 104 of the device cavity 108. As shown in FIG. 1, downstream of the first extension portion 231 are two successively arranged spherical extension portions 23. One of the extension portions 23 is positioned at the free end downstream of the airflow guiding element 20, and the other is positioned immediately upstream thereof, between the extension portion 27 and the other extension portion 23.

[0353] The airflow guiding element 20 is made of cardboard or includes cardboard.

[0354] The length of the airflow guiding element 20 is about 8 mm. The maximum outer diameter or width of the airflow guiding element 20 is about 3 mm. The minimum outer diameter or width of the airflow guiding element 20 is about 1 mm. The diameter of the device cavity 108 can be about 7.25 mm to about 7.3 mm. The length of the device cavity 108 is at least about 15 mm.

[0355] FIG. 2 shows an aerosol generating device 200 that is different from the aerosol generating device 100 shown in FIG. 1 in that the airflow guiding element 201 has a different structure and the device 200 includes a base support element 25 and a longer device cavity 208. The airflow guiding element 201 has an irregular outer surface such that the outer diameter of the airflow guiding element 201 varies along its length. The airflow guiding element 20 includes a core elongated portion 21 and a plurality of extension portions 23 extending radially outward from the core elongated portion 21. The airflow guiding element 20 includes three extension portions 23. The first extension portion 201 is positioned at the free end downstream of the airflow guiding element 201, the second extension portion 23 is positioned immediately upstream of the first extension portion 23, and the third extension portion 201 is positioned at the fixed end upstream of the airflow guiding element 201. The extension portions 23 are spherical in shape. The airflow guiding element 201 is made of cardboard or includes cardboard.

[0356] The aerosol generating device 200 comprises a base support element 25 connected to the closed end of the distal end of the device cavity 103. The airflow guiding element 201 is connected 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 through it 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 projects about 3 mm from the closed end 103 of the device cavity 208.

[0357] The peripheral portion 26 of the base support element 25 is chamfered to facilitate engagement with the hollow upstream end of the aerosol generating article after insertion into the device cavity 208. The chamfered peripheral portion 26 of the base support element 25 functions as a centering guide for the article inserted into the aerosol generating device 200, ensuring that the inserted article is centered about 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.

[0358] The length of the airflow guiding element 201 is about 10 mm. The maximum outer diameter or width of the airflow guiding element 201 is about 3 mm. The minimum outer diameter or width of the airflow guiding element 201 is about 1 mm. The diameter of the device cavity 208 can be from about 7.25 mm to about 7.3 mm. The length of the device cavity 208 is at least about 20 mm.

[0359] FIG. 3 shows an aerosol generating device 300 that is different from the aerosol generating device 100 shown in FIG. 1 in that the airflow guiding element 202 has a different structure. The airflow guiding 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 guiding element 202 is about 10 mm. The outer diameter of the airflow guiding element 202 is about 3 mm. The airflow guiding element 202 is made of cardboard or includes cardboard.

[0360] FIG. 4 shows an aerosol generator 400 that is different from the aerosol generator 100 shown in FIG. 1 in that the airflow guiding element 203 has a different structure. The airflow guiding element 203 has an irregular outer surface such that the outer diameter of the airflow guiding element 203 varies along its length. The airflow guiding element 203 includes a core portion 213 and a plurality of extension portions 233 extending radially outward from the core portion 213. The airflow guiding 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 each separated from the upstream and downstream ends of the airflow guiding element 203 by a gap.

[0361] The airflow guiding element 203 is made of cardboard or includes cardboard.

[0362] The length of the airflow guiding element 203 is about 8 mm. The maximum outer diameter or width of the airflow guiding element 203 is about 3 mm. The minimum outer diameter or width of the airflow guiding element 203 is about 1 mm.

[0363] The aerosol article 1 shown in FIG. 5 includes a rod of the aerosol generating substrate 12 and a downstream section 14 provided downstream of the rod of the aerosol generating substrate 12. The aerosol article 1 extends from an upstream or distal end 16 that coincides with the upstream end of the aerosol generating substrate 12 to a downstream or mouth-side end 18 that coincides 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 in the present disclosure.

[0364] The aerosol article 1 has an outer diameter of about 7.25 mm.

[0365] The aerosol-generating substrate 12 comprises a hollow tubular substrate element 40 formed of a homogenized tobacco material. The hollow tubular substrate element 40 has a peripheral wall 42 that defines a longitudinal cavity 44 providing an unrestricted flow channel 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.

[0366] Each of the components of the aerosol-generating article shown in and described in this disclosure may be surrounded by a corresponding wrapper or may be joined together by one or more wrappers not shown in the figures.

[0367] Figure 6 shows an aerosol-generating article 2 different from the aerosol-generating article 1 in that it also comprises an upstream section 30 provided upstream of the aerosol-generating substrate 12. The upstream section 30 comprises an upstream element 34 in the form of a hollow tubular element defining an empty longitudinal cavity extending along its entire length. The downstream end of the upstream element 34 abuts against 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 inner diameter of the upstream element 34 correspond to the outer diameter and inner diameter of the aerosol-generating element 12 located immediately downstream.

[0368] Figure 7 shows an exemplary aerosol-generating system 10 comprising the aerosol-generating device 100 of FIG. 1 and an aerosol-generating article 1 received within the device cavity (or heating chamber) 108 of the aerosol-generating device 100. After insertion of the aerosol-generating article 1 into the device cavity 108, the airflow guiding element 20 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 guiding element 20. The aerosol-generating device 100 is configured such that during use, air enters the device cavity 108 and enters the aerosol-generating article through its upstream end when drawn out over its downstream end.

[0369] The annular air flow channel 22 is defined between the inner surface of the hollow aerosol generating substrate 12 and the outer surface of the air flow guiding element 20. When the user sucks on the mouth-side end 18 of the aerosol generating article 1, air can be drawn into the device 100 towards the distal closed end 103 of the device cavity 108 and around the article 1, where the air can reverse its direction and enter the article 1 through its upstream end. The air can then flow through the annular air flow channel 22 and proceed towards the downstream end 18 of the article 1.

[0370] The maximum thickness of the air flow channel 22 is approximately 1.13 mm, and the minimum thickness of the air flow channel 22 is approximately 2.13 mm.

[0371] FIG. 8 shows an exemplary aerosol generating system 101 comprising an aerosol generating device 200 and an aerosol generating article 2 received within the device cavity (heating chamber) 208 of the aerosol generating device 200. After inserting the aerosol generating article 2 into the device cavity 208, the air flow guiding 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 air flow guiding element 201. The hollow upstream end of the article 2 engages with the base support element 25. The aerosol generating device 200 is configured such that during use, air enters the device cavity 208 and can enter the aerosol generating article through its upstream end when drawn over its downstream end.

[0372] The annular air flow channel 22 is defined between the inner surface of the hollow aerosol generating substrate 12 and the outer surface of the air flow guiding element 201. When the user sucks on the mouth-side end 18 of the aerosol generating article 2, air can be drawn into the device 200 towards the distal closed end 103 of the device cavity 108 and around the article 2, where the air can reverse its direction and enter the article 2 through its upstream end through the base support element 25. The air can then flow through the annular air flow channel 22 and proceed towards the downstream end 18 of the article 1.

[0373] The maximum thickness of the airflow channel 22 is approximately 1.13 mm, and the minimum thickness of the airflow channel 22 is approximately 2.13 mm.

[0374] FIG. 9 shows an aerosol generator 500 that is different from the aerosol generator 100 shown in FIG. 1 in that the airflow guiding element 204 has a different structure. The airflow guiding 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 guiding element 204 is approximately 10 mm. The outer diameter of the airflow guiding element 20 is approximately 3 mm. The airflow guiding element 204 is made of cardboard or includes cardboard. The inner diameter of the airflow guiding element 204 is approximately 1.5 mm.

[0375] FIG. 10 shows an exemplary aerosol generation system 102 comprising the aerosol generator 500 of FIG. 1 and an aerosol generation article 1 received within the device cavity (heating chamber) 108 of the aerosol generator 500. After insertion of the aerosol generation article 1 into the device cavity 108, the airflow guiding element 204 is received within the substrate cavity 44 of the article 1, and the hollow aerosol generation substrate 12 of the article 1 effectively surrounds the airflow guiding element 201. The hollow upstream end of the article 1 engages with the base support element 25. Similarly, an annular airflow channel 22 is defined between the inner surface of the hollow aerosol generation substrate 12 and the outer surface of the airflow guiding element 204. When the user sucks on the mouth-side end 18 of the aerosol generation article 1, air can be drawn into the device 200 towards the distal closed end 103 of the device cavity 108 and around the article 2, where the air can reverse its direction and enter the article 1 through its upstream end. The air can then flow through the annular airflow channel 22 and proceed towards the downstream end 18 of the article 1. In addition to the air flowing around the airflow guiding element 204 along the annular airflow channel 22, air can flow into the interior of the hollow tube of the airflow guiding element 204 through a porous portion (not shown) present at the base of the airflow guiding element 204. The internal longitudinally-directed cavity defined by the airflow guiding element 204 defines a secondary airflow channel 24 that extends from the upstream end of the airflow guiding element 204 and exits through the open downstream end of the airflow guiding element 204.

[0376] The thickness of the airflow channel 22 is approximately 2.13 mm. The inner diameter of the airflow guiding element 204 shown defines the diameter or width of the secondary airflow channel 24.

[0377] In all of the figures of the present disclosure, the airflow paths, aerosol flow paths, or other fluid paths to and through the aerosol generating articles and devices in use are indicated by discontinuous arrows.

[0378] For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, etc. are to be understood as being modified in all instances by the term "about". Also, all ranges include the disclosed maximum and minimum points, and any intermediate ranges therebetween, whether specifically enumerated herein or not. Thus, in this context, the number A is understood as A ± 10%. Within this context, the number A may be considered to include numerical values within the general standard error of the measurement of the property that the number A modifies. The number A may deviate by the percentages recited above in some instances used in the appended claims, provided that the amount by which A deviates does not substantially affect the basic and novel characteristics of the claimed invention. Also, all ranges include the disclosed maximum and minimum points, and any intermediate ranges therebetween, whether specifically enumerated herein or not.

[0379] The specific embodiments and examples described above illustrate, but do not limit, the present invention. It is understood that other embodiments of the present invention may be made and that 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 is A heating chamber for receiving and heating the aerosol-generating article, The apparatus comprises an airflow guide element located within the heating chamber and extending in the longitudinal direction toward the mouth end of the apparatus, configured to be inserted into the aerosol generating article when received within the heating chamber, The width or outer diameter of the airflow guide element varies along its length, and a first portion of the airflow guide element has a width or outer diameter corresponding to the maximum width or outer diameter of the airflow guide element, and a second portion of the airflow guide element located upstream of the first portion has a width or outer diameter smaller than the maximum width or outer diameter of the airflow guide element. The aerosol generating article comprises an aerosol generating substrate, the aerosol generating substrate having a hollow tubular segment that defines a substrate cavity extending from the upstream end to the downstream end of the aerosol generating substrate, and when the aerosol generating article is received into the heating chamber of the apparatus, the airflow guide element extends in the longitudinal direction within the substrate cavity, and an airflow channel is defined between the outer surface of the airflow guide element and the inner surface of the aerosol generating substrate. An aerosol generating system in which the aerosol generating article comprises a downstream section located downstream of the aerosol generating substrate, and the downstream section comprises one or more of a mouthpiece element and a hollow tubular element.

2. The 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. The aerosol generating system according to claim 2, wherein the heating element is provided around or near 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 is The device includes a heating chamber at the mouth end for receiving an aerosol generating article, A heating element provided around or near the heating chamber for heating an aerosol-generating article received in the heating chamber, The apparatus comprises an airflow guide element located within the heating chamber and extending in the longitudinal direction toward the mouth end of the apparatus, configured to be inserted into the aerosol generating article when received within the heating chamber, The aerosol generating article comprises an aerosol generating substrate, the aerosol generating substrate having a hollow tubular segment that defines a substrate cavity extending from the upstream end to the downstream end of the aerosol generating substrate, and when the aerosol generating article is received into the heating chamber of the apparatus, the airflow guide element extends in the longitudinal direction within the substrate cavity, and an airflow channel is defined between the outer surface of the airflow guide element and the inner surface of the aerosol generating substrate. An aerosol generating system in which the aerosol generating article comprises a downstream section located downstream of the aerosol generating substrate, and the downstream section comprises one or more of a mouthpiece element and a hollow tubular element.

5. The aerosol generating system according to claim 1 or 4, wherein the outer surface of the airflow guide element is textured or non-uniform.

6. The aerosol generating system according to claim 1 or 4, wherein the maximum width or diameter of a portion of the airflow guide element extending into the heating chamber is preferably at least about 25 percent of the diameter of the heating chamber and at least about 50 percent of the diameter of the heating chamber.

7. The aerosol generating system according to claim 1 or 4, wherein the airflow guide element extends along at least 50 percent of the length of the heating chamber.

8. The aerosol generating system according to claim 1 or 4, wherein the airflow guide element comprises an airflow inlet at a first position and an airflow outlet at a second position downstream of the first position, such that the airflow path is defined within and along the airflow guide element.

9. The aerosol generating system according to claim 1 or 4, wherein the airflow guide element comprises a hollow tube.

10. The aerosol generating system according to claim 1 or 4, wherein the airflow guide element comprises an elongated body having a central core portion and an extension portion located along the core portion, the extension portion extending outward from the core portion, preferably the airflow guide element having at least two extension portions located along the core portion.

11. The aerosol generating system according to claim 1 or 4, wherein the wall thickness of the aerosol generating substrate is 5 percent to 40 percent of the outer diameter of the aerosol generating substrate.

12. The aerosol generating system according to claim 1 or 4, wherein the width or diameter of the airflow guide element is smaller than the diameter of the substrate cavity.

13. The aerosol generating system according to claim 1 or 4, wherein the maximum width or diameter of the portion of the airflow guide element extending into the substrate cavity is at least about 25 percent of the diameter of the substrate cavity.

14. The aerosol generating system according to claim 1 or 4, wherein the aerosol generating article is configured to extend beyond the mouth end of the aerosol generating device when it is received inside the aerosol generating device.

15. The aerosol generating system according to claim 1 or 4, wherein the aerosol generating article comprises a downstream section located downstream of the aerosol generating substrate, and the downstream section is configured to be received through the mouth end of the heating chamber.

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