Aerosol-generating article comprising an airflow guiding element extending within a tubular substrate

Abstract

There are provided aerosol-generating articles (1, 2, 3, 4, 5) for generating an inhalable aerosol upon heating. The aerosol-generating article comprises an aerosol-generating substrate (40) in the form of a hollow tubular segment that defines a substrate cavity (44) extending from an upstream end of the aerosol-generating substrate to a downstream end of the aerosol-generating substrate. The aerosol-generating article comprises an airflow guiding element (20) that extends in the longitudinal direction within the substrate cavity and defines an airflow channel (22) between an outer surface of the airflow guiding element and an inner surface of the aerosol-generating substrate. The width or diameter of the airflow guiding element is smaller than the diameter of the substrate cavity.

Description

Technical Field

[0001] The present invention relates to an aerosol generating article comprising a rod of an aerosol generating substrate adapted to generate an inhalable aerosol upon heating.

Background Art

[0002] Aerosol generating articles in which an aerosol generating substrate such as a tobacco-containing substrate is heated rather than burned are known in the art. Typically, in such heated smoking articles, an aerosol is generated by transferring heat from a heat source to a physically separated aerosol generating substrate or material, which may be 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] Numerous prior art documents disclose aerosol generating devices for consuming aerosol generating articles. Such devices include, for example, an electrically heated aerosol generating device in which an aerosol is generated by heat transfer from one or more electric heater elements of the aerosol generating device to the aerosol generating substrate of the heated aerosol generating article. For example, an electrically heated aerosol generating device has been proposed that comprises 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, WO 2020 / 115151 describes the provision of an external heating element disposed around the perimeter of an aerosol generating article when the aerosol generating article is received within a cavity of an aerosol generating device. Alternatively, an inductively heatable aerosol generating article comprising an aerosol generating substrate and a susceptor disposed within the aerosol generating substrate has been proposed by WO 2015 / 176898.

[0004] In general, it can be difficult to provide efficient heating of the aerosol generating substrate across the entire rod of the substrate. 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 element is used to heat the rod of the 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 is potentially wasted.

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

[0006] Accordingly, it is desirable to provide an aerosol generating article having an aerosol generating substrate that is adapted to provide more efficient aerosolization of the aerosol generating substrate and reduces waste of substrate material 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 generating substrate. It would be desirable to provide such an aerosol generating article that can provide optimized delivery of the aerosol from the aerosol generating 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 resistive heating devices.

Summary of the Invention

[0007] An aerosol generating article for generating an inhalable aerosol upon heating is provided. 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 between an upstream end and a downstream end of the aerosol generating substrate. The aerosol generating article may include an airflow guiding element. The airflow guiding element may extend axially within the substrate cavity. The airflow guiding element may include an elongated body extending axially within the substrate cavity. An airflow channel may be defined between an outer surface of the airflow guiding element and an inner surface of the aerosol generating substrate. The width or diameter of the airflow guiding element may be smaller than the diameter of the substrate cavity. The aerosol generating substrate may be referred to as a hollow tubular substrate.

[0008] Although by way of illustration only, the present invention will be further described with reference to the following accompanying drawings.

Brief Description of the Drawings

[0009]

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Mode for Carrying Out the Invention

[0010] According to the present invention, there is provided an aerosol generating article for generating 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 that defines a substrate cavity extending between an upstream end of the aerosol generating substrate and a downstream end of the aerosol generating substrate. The aerosol generating article includes an air flow guiding element. The air flow guiding element extends in the longitudinal direction within the substrate cavity. An air flow channel is defined between the outer surface of the air flow guiding element and the inner surface of the aerosol generating substrate. The width or diameter of the air flow guiding element may be smaller than the diameter of the substrate cavity. The aerosol generating substrate may be referred to as a hollow tubular substrate.

[0011] As used herein in connection with the present disclosure, the term "aerosol generating article" is used to describe an article comprising an aerosol generating substrate that generates an aerosol that is heated and inhalable for delivery to a user.

[0012] As used herein in connection with 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.

[0013] As used herein in connection with 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.

[0014] 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 end of the aerosol generating article. During use, the user directly or indirectly inhales at the downstream end of the aerosol generating article to inhale the aerosol generated by the aerosol generating article.

[0015] An aerosol generating article according to the present disclosure has an upstream end. The upstream end is opposite to the downstream end. The upstream end of the aerosol generating article may also be referred to as the distal end of the aerosol generating article.

[0016] The components of an aerosol generating article 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.

[0017] As used herein in connection with the present invention, the term "longitudinal direction" refers to the direction between the upstream end and the downstream end of the aerosol generating article that are opposite to each other.

[0018] As used herein in connection with the present disclosure, the term "transverse direction" is used to describe a direction perpendicular to the longitudinal axis direction.

[0019] As used herein in connection with the present disclosure, the term "cross-section" is used to refer to the cross-section of an aerosol-generating article, or a component thereof, unless otherwise specified.

[0020] As used herein in connection with 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 in connection with 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.

[0021] As used herein in connection with 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 in connection with 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.

[0022] As used herein in connection with the present disclosure, the term "homogenized tobacco material" encompasses any material formed by the agglomeration of tobacco particles. The homogenized tobacco material may be manufactured by casting, extrusion, papermaking processes, or any other suitable process known in the art.

[0023] As used herein in connection with 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 being compounds derived from tobacco, are not considered tobacco particles for the purposes of the present disclosure.

[0024] By providing a substrate element in a tubular form, advantageously, the amount of tobacco material in the aerosol-generating substrate can be optimized, such that 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 comprising external heating means, the central portion of the homogenized tobacco material, which may not be heated as effectively towards the outer portions, 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 an 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.

[0025] 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 to match the heating zone of the 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.

[0026] The hollow tubular substrate element has a relatively simple structure that can be manufactured in a simple and cost-effective manner using existing equipment. Subsequently, the hollow tubular substrate element can be incorporated into an aerosol-generating article having other components using known assembly methods and equipment.

[0027] By providing an airflow guiding element that extends axially within the empty substrate cavity defined by the hollow tubular aerosol-generating substrate, an airflow channel or path is defined between the outer surface of the airflow guiding element and the interior of the aerosol-generating substrate around the airflow guiding element such that air entering the substrate cavity is promoted to flow near 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. As a result, the air entering the cavity can be locally accelerated as it flows through such an airflow path in accordance with Bernoulli's theorem. Such local airflow acceleration can 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 the hollow tubular substrate, shortening the time required for the substrate to generate a perceptually acceptable aerosol after being initially heated, while reducing the potential waste of substrate material that may not have contributed to aerosol generation and manufacturing costs.

[0028] 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 a homogenized tobacco material such as cast leaf.

[0029] The hollow tubular substrate element is preferably formed of two or more overlapping layers of a homogenized tobacco material, more preferably three or more overlapping layers of a homogenized tobacco material.

[0030] The hollow tubular substrate element is preferably formed of up to about 10 overlapping layers of homogenized tobacco material, more preferably up to about 5 overlapping layers of homogenized tobacco material. For example, the hollow tubular substrate element may be formed of 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.

[0031] The plurality of overlapping layers of homogenized tobacco material preferably directly overlap one another such that adjacent layers directly contact one another without an intervening layer.

[0032] The multi-layer arrangement of the layers provides 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 longitudinally extending substrate cavity.

[0033] The layers of homogenized tobacco material are preferably in the form of sheets. As used herein in connection with the present disclosure, the term "sheet" describes a thin, layer-like element having a width and length that are substantially greater than its thickness.

[0034] The hollow tubular substrate element may have a length of at least about 5 millimeters, or at least 7 millimeters, or at least about 10 millimeters.

[0035] 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.

[0036] 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.

[0037] The hollow tubular substrate element preferably has a length of about 12 millimeters.

[0038] As described above, the length of the hollow tubular substrate element can advantageously match the longitudinal dimension of the heating element in 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.

[0039] Preferably, the ratio of the length of the hollow tubular substrate element to the total length of the aerosol generating article is at least about 0.1. More preferably, the ratio of the length of the hollow tubular substrate element to the total length of the aerosol generating article is at least about 0.15. Even more preferably, the ratio of the length of the hollow tubular substrate element to the total length of the aerosol generating article is at least about 0.2.

[0040] 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. Even 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.

[0041] 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 even more preferably from about 0.2 to about 0.5.

[0042] Preferably, the hollow tubular substrate element has an outer diameter less than the outer diameter of the aerosol generating article.

[0043] Preferably, the hollow tubular substrate element can have an outer diameter of at least about 5 millimeters, or at least about 5.5 millimeters, or at least about 6 millimeters.

[0044] Preferably, the hollow tubular substrate element can have an outer diameter of at most about 9 millimeters, or at most about 8 millimeters, or at most about 7.5 millimeters.

[0045] For example, the hollow tubular substrate element may have an outer diameter of from about 5 millimeters to about 9 millimeters, or from about 5.5 millimeters to 8 millimeters, or from about 6 millimeters to about 7.5 millimeters.

[0046] 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.

[0047] As used herein in connection with 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 a component thereof. 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 a component thereof along the entire length of the aerosol generating article or a component thereof may fall within the same range or 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 a component thereof at all positions along the length of the aerosol generating article or a component thereof may fall within the same range or have the same value.

[0048] 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.

[0049] 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 can 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 the desired draw resistance (RTD) to the hollow tubular substrate element.

[0050] 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.

[0051] The hollow tubular substrate element may have a wall thickness that is at most about 40 percent of the outer diameter of the hollow tubular substrate element, or at most about 30 percent of the outer diameter of the hollow tubular substrate element, or at most about 20 percent of the outer diameter of the hollow tubular substrate element.

[0052] 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.

[0053] The hollow tubular substrate element preferably has a wall thickness of about 7 percent of the outer diameter of the hollow tubular substrate element.

[0054] 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 0.5 millimeter. The hollow tubular substrate element may have a wall thickness of at least 0.6 millimeter. The hollow tubular substrate element may have a wall thickness of at least 0.8 millimeter. The hollow tubular substrate element may have a wall thickness of at least about 1 millimeter.

[0055] The hollow tubular substrate element may have a wall thickness of at most about 3 millimeters, or at most about 2 millimeters, or at most about 1 millimeter.

[0056] 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.

[0057] The hollow tubular substrate element may have a wall thickness of from about 0.5 millimeter to about 2 millimeters. The hollow tubular substrate element may have a wall thickness of from about 1 millimeter to about 2 millimeters.

[0058] The hollow tubular substrate element may have a wall thickness of about 0.5 millimeter. The hollow tubular substrate element may have a wall thickness of about 1 millimeter.

[0059] As described above, the cavity in the longitudinal axis 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 describe 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.

[0060] Thus, the cavity in the longitudinal axis should not include any components that would impede the longitudinal air flow. The cavity in the longitudinal axis is preferably substantially empty. The cavity in the longitudinal axis is more preferably empty.

[0061] The cavity in the longitudinal axis may also be referred to as the longitudinal air flow channel.

[0062] The cavity in the longitudinal axis extends between the two ends of the hollow tubular substrate element and is preferably open at both the upstream end and the downstream end. The open upstream end may provide the main air inlet for drawing air through the aerosol-generating article when the consumer smokes the article. The cavity in the longitudinal axis may thus provide the main passage for the flow of air and aerosol through the article.

[0063] 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.

[0064] 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.

[0065] For example, the aerosol generating substrate may 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.

[0066] The diameter of the cavity in the major axis direction corresponds to the inner diameter of the hollow tubular substrate element.

[0067] The cavity in the major axis direction may have a diameter of at least about 1 millimeter, or at least about 2 millimeters, or at least about 3 millimeters.

[0068] 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.

[0069] 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.

[0070] The cavity in the major axis direction may have a diameter of about 6 millimeters.

[0071] The diameter of the cavity in the major axis direction can 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 a specification 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.

[0072] 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.

[0073] The cavity in the major axis direction preferably has a substantially circular cross-section. Alternatively, the cavity in the major axis direction may have a substantially elliptical cross-section.

[0074] The cavity in the major axis direction may have a constant diameter along the length of the hollow tubular substrate element. However, the diameter of the cavity in the major axis direction may vary along the length of the hollow tubular substrate element.

[0075] The central major axis direction axis of the hollow tubular substrate element preferably aligns with the central major axis direction 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 major axis direction axis of the hollow tubular substrate element preferably aligns with the central major axis direction axes of both the upstream element and the downstream element. The central major axis direction axis of the hollow tubular substrate element preferably aligns with the central major axis direction axis of the aerosol generating article.

[0076] The hollow tubular substrate element may include one or more susceptor elements positioned in contact with the peripheral wall for inductive heating of the homogenized tobacco material during use.

[0077] 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 may be the result of at least one of the hysteresis losses and eddy currents induced within the susceptor, depending on the electrical and magnetic properties of the susceptor material.

[0078] 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 airflow channel in the longitudinal axis direction. Alternatively, or additionally, the hollow tubular substrate element may comprise one or more susceptor elements on the outer surface of the peripheral wall.

[0079] 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 the volatile compound from the aerosol generating substrate. Suitable materials for the elongated susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium, and composites of metallic materials. Some susceptor elements contain metal or carbon. Advantageously, the susceptor element can include 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 aluminum or can contain aluminum. The susceptor element preferably contains a ferromagnetic material or a paramagnetic material 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 elongated susceptor elements can be heated to a temperature exceeding about 250 degrees Celsius.

[0080] The aerosol generating article according to the present disclosure may further comprise 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 comprise 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.

[0081] The aerosol-generating article of the present disclosure preferably comprises an upstream element that is located upstream of and adjacent to the aerosol-generating substrate. The upstream element preferably prevents direct physical contact with the upstream end of the aerosol-generating substrate.

[0082] Furthermore, the presence of the upstream element helps to prevent any loss of the substrate, which may be advantageous, for example, when the substrate contains particulate plant material.

[0083] When the aerosol-generating substrate includes shredded tobacco such as tobacco cut filler, the upstream section or its elements may additionally help 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.

[0084] The upstream section or its upstream element may also provide some protection to the aerosol-generating substrate during storage, in order to at least partly cover the upstream end of the aerosol-generating substrate that would otherwise be exposed.

[0085] In the case of an aerosol-generating article intended to be inserted into a cavity in an aerosol-generating device so that the aerosol-generating substrate can be externally heated within the cavity, advantageously, the upstream section or its upstream element may facilitate insertion of the upstream end of the article into the cavity. Inclusion of the 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.

[0086] The upstream section or its upstream element may also provide an improved appearance to the upstream end of the aerosol-generating article. Furthermore, if desired, the upstream section, or its upstream element, may be used to provide information about the aerosol-generating article, such as information regarding the brand, flavor, content, or details of the aerosol-generating device in which the aerosol-generating article is intended to be used.

[0087] 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 drilling. The plurality of openings are preferably uniformly distributed across the cross-section of the upstream element. The porosity or permeability of the upstream element is advantageously designed to provide an aerosol generating article having a specific overall draw resistance (RTD) that does not substantially affect the filtration provided by other parts of the article.

[0088] 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 venting means provided within the wrapper and into the rod of the aerosol generating substrate.

[0089] The upstream element may be formed of a solid cylindrical plug element having a filled cross-section. Such plug elements may be referred to as "plane" elements. The solid plug element may be porous as described above, but does not have a tubular form and thus does not provide a longitudinal flow channel. The solid plug element preferably has a substantially uniform cross-section.

[0090] The upstream element may be formed of a hollow tubular segment that defines a longitudinal cavity providing an unrestricted flow channel. Thus, the upstream element can provide protection against the aerosol generating substrate, as described above, while having a minimal effect on the overall draw resistance (RTD) and filtration characteristics of the article.

[0091] 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, 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.

[0092] Preferably, the wall thickness of the hollow tubular segment is less than 2 millimeters, more preferably less than 1.5 millimeters, and even more preferably less than 1 millimeter.

[0093] 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, for example, the same material as that used for one of the other components of the aerosol generating article such as a downstream filter segment or a hollow tubular cooling element. Suitable materials for forming the upstream element include filter materials, ceramics, polymer materials, cellulose acetate, cardboard, zeolites, or aerosol generating substrates. The upstream element may include a plug of cellulose acetate. The upstream element may comprise a hollow acetate tube or a cardboard tube.

[0094] 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.

[0095] Preferably, the upstream section or upstream element has a length of from 2 millimeters to 10 millimeters, more preferably from 3 millimeters to 8 millimeters, and even more preferably from 2 millimeters to 6 millimeters. In a particularly preferred embodiment, the upstream section or upstream element has a length of 5 millimeters. The length of the upstream section or upstream element may 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 upstream element may be increased to maintain the same overall length of the article.

[0096] In addition, in the case of an article intended to be externally heated, the length of the upstream section or its upstream elements 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.

[0097] The upstream section is preferably surrounded by a wrapper such as a plug wrap. The wrapper surrounding the upstream section is preferably a rigid 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. This provides structural rigidity to the upstream section.

[0098] The upstream section is preferably connected, by means of the outer wrapper described herein, to the rod of the aerosol-generating substrate and optionally to at least a part of the downstream section.

[0099] The upstream section may include a heat source, preferably a combustible heat source, and a heat-conductive element. The heat source may define the upstream end of the aerosol-generating article. The heat-conductive element may be positioned in direct contact between the heat source and the aerosol-generating substrate. The heat-conductive element may conduct heat from the heat source to the aerosol-generating substrate. The heat-conductive element may partially surround the aerosol-generating substrate. The heat-conductive element may partially surround the heat source. The heat source, the heat-conductive element, and the aerosol-generating substrate may be axially aligned in a continuously abutting manner. The aerosol-generating substrate, which is tubular, may include at least one perforation for providing an air inlet. The air inlet may provide fluid communication between the substrate cavity and the exterior of the aerosol-generating article. Suitable combustible heat sources for use in aerosol-generating articles are known in the art. The combustible heat source is preferably a combustible carbonaceous heat source. As used herein in connection with the present invention, the term "carbonaceous" is used to describe a combustible heat source containing carbon.

[0100] Similar aerosol-generating articles comprising such an upstream section with a heat source and a heat-conductive element are further described in WO-A-2015 / 028654, WO-A-2015 / 022321, and WO-A-2009 / 022232.

[0101] As described above, the aerosol-generating article comprises an airflow guiding element. The airflow guiding element extends in the longitudinal direction within a longitudinal substrate cavity. A primary airflow path or channel is 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.

[0102] The airflow guiding element may extend into the substrate cavity from any position along the aerosol-generating article. Preferably, the airflow guiding element extends into the substrate cavity from a position upstream of the aerosol-generating substrate. The airflow guiding element may extend into the substrate cavity from a position downstream of the aerosol-generating substrate.

[0103] As described above, the aerosol generating article may comprise an upstream section located upstream of the aerosol generating substrate. The airflow guiding element may be coupled to or held by an upstream element adjacent to the upstream end of the aerosol generating substrate. The airflow guiding element may be coupled to or held by a downstream element adjacent to the downstream end of the aerosol generating substrate. The airflow guiding element coupled to or held by the upstream or downstream element enables the airflow guiding element to be supported by such upstream or downstream elements instead of being supported by the aerosol generating substrate itself. Thereby, it is possible to extend the airflow guiding element into the cavity of the aerosol generating substrate without relying on a manufacturing or assembly process that may involve winding the aerosol generating substrate or otherwise affect the structural integrity of the substrate during the manufacturing or assembly process. Therefore, this allows for the extension of an airflow guiding element having a maximum width or diameter smaller than the inner diameter of the aerosol generating substrate into the cavity of the aerosol generating substrate without any internal contact between the airflow guiding element and the aerosol generating substrate. In other words, the airflow guiding element may be effectively cantilevered and extend into the cavity of the substrate without the need to support winding or surrounding the aerosol generating substrate around the airflow guiding element or a portion thereof.

[0104] The aerosol generating article may comprise a base support element from which the airflow guiding element may extend. The upstream section may include such a base support element. In other words, the base support element may be an upstream element. The base support element may be located upstream of the aerosol generating substrate. The downstream end of the base support element may abut the upstream end of the aerosol generating substrate. The outer diameter of the base support element may be substantially equal to the outer diameter of the aerosol generating substrate.

[0105] The base support element may be located downstream of the aerosol generating substrate such that the airflow guiding element may extend from a position downstream of the aerosol generating substrate. Thus, the base support element may be a downstream element of the downstream section of the aerosol generating article.

[0106] The base support element may be located within an upstream element positioned upstream of the aerosol generating substrate. The base support element may be located within a downstream element positioned downstream of the aerosol generating substrate. The base support element may be held or embedded within an upstream element positioned upstream of the aerosol generating substrate. The base support element may be held or embedded within a downstream element positioned downstream of the aerosol generating substrate. For example, the downstream or upstream element may include a hollow tubular element defining a cavity in the longitudinal axis direction, and the base support element may be sized to be held within such a longitudinal axis direction cavity.

[0107] The base support element may have a disk or plate shape, and preferably has a cylindrical shape. The base support element is preferably porous or includes at least one opening. This enables the establishment of fluid communication between the exterior of the aerosol generating article and the interior of the aerosol generating substrate through the base support element.

[0108] The airflow guiding element preferably includes an elongated body extending in the longitudinal axis direction within the substrate cavity. The airflow guiding element preferably includes an elongated body extending from the upstream end of the airflow guiding element to the downstream end of the airflow guiding element. The airflow guiding element preferably includes an elongated body extending from the fixed end of the airflow guiding element to the free end of the airflow guiding element.

[0109] When the base support element is located upstream of the aerosol generating substrate, the upstream end of the airflow guiding element may be coupled to the base support element. When the base support element is located downstream of the aerosol generating substrate, the downstream end of the airflow guiding element may be coupled to the base support element. The central longitudinal axis direction axis of the airflow guiding element may be aligned with the central longitudinal axis direction axis of the base support element. The airflow guiding element preferably includes 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 coupled to the base support element may define the fixed end of the airflow guiding element, and the opposing end may be the free end of the airflow guiding element.

[0110] 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.

[0111] 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.

[0112] The elongated body of the airflow guiding element may be rod-shaped or conical. The elongated body of the airflow guiding element preferably includes a hollow body or a tube defining an empty cavity in the longitudinal axis direction. The elongated body of the airflow guiding element preferably includes a hollow cylindrical tube defining an empty cavity in the longitudinal axis direction.

[0113] The downstream end of the hollow body may be closed so that air cannot flow into the base cavity through the interior of the hollow body.

[0114] The airflow guiding element may include 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 along it within the airflow guiding element.

[0115] The downstream end of the hollow body may be porous or provided with one or more perforations, openings, inlets, or outlets such 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. 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 is defined within the airflow guiding element. 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.

[0116] 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 outside of the aerosol-generating article and the inside of the aerosol-generating substrate 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 into the substrate cavity through the base support element 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 substrate and the outer surface of the airflow guiding element. In other words, the primary airflow path or channel may surround the airflow guiding element.

[0117] When the airflow guiding element includes a hollow body, perforations or holes extending through the peripheral wall of the hollow body defining an empty cavity in the longitudinal axis direction may be provided. 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 inside of the hollow body and the substrate cavity such that one or more secondary airflow paths into the substrate cavity are defined. Air may flow into the hollow body or tube of the airflow guiding element through the base support element and out into the substrate cavity through the peripheral wall of the hollow body. Air moving through the hollow body may also exit into the substrate 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.

[0118] 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 substrate cavity during use.

[0119] The airflow guiding element may be textured. The airflow guiding element may have a rough or 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, dimples, bumps, protrusions, or bulges provided on its outer surface. By having a textured or rough outer surface, the airflow guiding element has the ability to disrupt the air flowing around it so as to form local turbulence, thereby enhancing the mixing of the air and the aerosol-forming components released.

[0120] 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.

[0121] The airflow guiding element may include an elongated core portion by the above-described elongated body and at least one extension portion positioned along the core portion. The at least one extension portion may include a bump, a protrusion, or a 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 (in other words, 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 circumferentially around the core portion, either completely or partially.

[0122] The airflow guiding element may include at least two extension portions positioned along the core portion. Each extension portion may be located at its respective major axis direction or axial direction position along the core portion. The airflow guiding element may include three extension portions positioned along the core portion.

[0123] The extension portion may be substantially shaped in the form of a sphere, a hemisphere, a cylinder, or a ring. By providing one or more extension portions along the core portion of the airflow 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 then promotes 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 and the aerosol forming components released from the heated aerosol generating substrate.

[0124] Each extension of the airflow guiding element may extend along the core part by a specific length. The length of each or the extension 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 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 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 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 of the airflow guiding element may be at least about 25 percent of the total length of the airflow guiding element.

[0125] The length of each or the extension 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 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 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 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 of the airflow guiding element may be at most about 35 percent of the total length of the airflow guiding element.

[0126] When a plurality of extensions are provided, each extension may have a different length. For example, the airflow guiding element may include three extensions sequentially arranged along the core part. The first extension may extend along about 15 percent of the total length of the airflow guiding element, and the other two extensions may extend along about 35 percent of the total length of the airflow guiding element.

[0127] Advantageously, the amount of turbulence and turbulent flow created in the air flowing around the airflow guiding element can be adjusted according to the size of the extension with respect to the airflow guiding element, the position of the extension or each extension along the airflow guiding element, and the distance between consecutive or adjacent extensions.

[0128] The extension may be provided at the upstream end of the airflow guiding element or its core part. The extension may be provided at the downstream end of the airflow guiding element or its core part.

[0129] Continuous or adjacent extensions may be spaced from each other via a gap so as to define a gap therebetween. The extensions may be equally spaced from each other via a gap. Providing a gap between continuous or adjacent extensions 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 or before flowing over the downstream extension, mainly when the cross-section of the extension is uniform along its length, such as cylindrical or ring-shaped. The outer surface of the core part may be exposed by such gaps.

[0130] The base support element and the airflow guiding element may be manufactured separately before the assembly of the aerosol generating article and then joined 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 may be manufactured separately before the assembly of the aerosol generating article and then joined to each other. The core part of the airflow guiding element and any extension may be integrally formed with each other, for example, by extrusion or by injection molding. The extension may be manufactured separately from the core part and then assembled onto the core part. For example, the extension may be a ring-shaped or cylindrical element that is mounted on and joined to the core part. For example, such a ring-shaped or cylindrical element may slide onto the core part and be joined to the core part by adhesion or interference fit.

[0131] 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 the present disclosure can provide a suitable resistance to deformation or compression while providing base support elements and airflow guiding elements that can be manufactured cost-effectively.

[0132] 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.

[0133] The airflow guiding element may include an outer layer or coating that is at least partially provided on the outer surface, preferably the outer 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 conform to the aerosol formers, flavorants, and aerosol generating substrates described in the present disclosure.

[0134] The length of the airflow guiding element preferably corresponds to the amount by which the airflow guiding element extends into the substrate cavity.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] The central axis or longitudinal axis of the airflow guiding element is preferably aligned with the central axis or longitudinal axis of the aerosol generating substrate. The airflow guiding element is preferably axially symmetric. Thereby, it can be ensured 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.

[0141] The airflow guiding element has a maximum outer diameter. One or more raised surfaces or extension parts of the airflow guiding element may define the maximum outer diameter or width of the airflow guiding element. Therefore, the diameter or width of the airflow guiding element may vary or oscillate along the length of the airflow guiding element.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] A portion of the airflow guiding element having a diameter corresponding to the maximum outer diameter or width of the airflow guiding element may be 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 may be located away from (or downstream of) the base or upstream end of the airflow guiding element at 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 may be located away from (or downstream of) the base or upstream end of the airflow guiding element at 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 may be located away from (or downstream of) the base or upstream end of the airflow guiding element at 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 may be located away from (or downstream of) the base or upstream end of the airflow guiding element at at least about 50 percent of the length of the airflow guiding element.

[0147] The diameter of a portion of the airflow guiding element upstream of a portion of the airflow guiding element having a diameter corresponding to the maximum outer diameter or width of the airflow guiding element, or any diameter, is preferably less than (or does not exceed) the maximum outer diameter or width of the airflow guiding element.

[0148] The airflow guiding element may have 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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 centering the airflow guiding element with the substrate cavity and may assist in holding the airflow guiding element within the substrate cavity.

[0154] 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 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. Preferably, such defined airflow channels may be referred to as primary airflow channels or restricted airflow channels.

[0155] The airflow channel preferably has an 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.

[0156] 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 specific longitudinal and circumferential positions along its elongated body, the height or thickness of the airflow channel may vary in the longitudinal direction, the circumferential direction, or both.

[0157] 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.

[0158] 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. The airflow guiding element does not have to contact the inner surface of the aerosol generating substrate. Along its entire length, the airflow guiding element does not have to 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 definition of the airflow channel that is thicker and less obstructed, thereby allowing more airflow to move between the inner surface of the aerosol generating substrate and the airflow guiding element.

[0159] 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.

[0160] 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.

[0161] 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.

[0162] 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.

[0163] 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. With this arrangement, the flow of aerosol from the airflow channel in the longitudinal axis direction of the hollow tubular substrate element into the downstream section and through the aerosol generating article can be optimized.

[0164] 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.

[0165] The hollow tubular element of the downstream section may also be referred to as a hollow tubular downstream element.

[0166] In the context of the present disclosure, the hollow tubular element of the downstream section provides an unrestricted flow channel through the air flow path. This means that the hollow tubular element provides a negligible level of draw resistance (RTD) as defined above. Thus, the air flow path should not include any components that would impede the flow of air in the longitudinal direction. Preferably, the air flow path is substantially empty.

[0167] The hollow tubular element of the downstream section provides an empty cavity downstream of the aerosol-generating substrate, whereby the cooling and nucleation of aerosol particles generated by the aerosol-generating substrate can be improved. Thus, the hollow tubular element of the downstream section can function as an aerosol cooling element.

[0168] 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.

[0169] 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.

[0170] 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.

[0171] The 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 advantages of nucleation described above are maximized, whereby aerosol formation and cooling can be improved.

[0172] 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.

[0173] 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.

[0174] 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.

[0175] 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.

[0176] 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.

[0177] 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.

[0178] The ratio of the length of the hollow tubular element of 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 of 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 of the downstream section to the total length of the aerosol generating article may be about 0.60 or less.

[0179] The ratio of the length of the hollow tubular element of 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 of 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 of the downstream section to the total length of the aerosol generating article may be at least about 0.40.

[0180] For example, the ratio of the length of the hollow tubular element of 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.

[0181] The wall thickness of the hollow tubular element of the downstream section may be at least about 100 micrometers. The wall thickness of the hollow tubular element of the downstream section may be at least about 150 micrometers. The wall thickness of the hollow tubular element of 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).

[0182] The wall thickness of the hollow tubular element of 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 of the downstream section may be about 1 millimeter or less. The wall thickness of the hollow tubular element of the downstream section may be about 500 micrometers or less.

[0183] 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.

[0184] 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 components leave 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 a certain degree of 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 favorable for aerosol nucleation. Furthermore, by utilizing a hollow tubular element having a relatively small thickness, it may be possible to substantially prevent the diffusion of the ventilation air before it contacts and mixes with the aerosol flow, which is also understood to be more favorable 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.

[0185] The hollow tubular element of the downstream section preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol generating substrate and the outer diameter of the aerosol generating article. The hollow tubular element of the downstream section preferably has an outer diameter that is larger than the outer diameter of the hollow tubular substrate element of the aerosol generating substrate.

[0186] The hollow tubular element may have an outer diameter of 5 millimeters to 10 millimeters, for example, 5.5 millimeters to 9 millimeters, or 6 millimeters to 8 millimeters.

[0187] 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.

[0188] 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.

[0189] 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 drawing resistance of the hollow tubular segment can be advantageously reduced.

[0190] 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.

[0191] 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.

[0192] 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.

[0193] The central longitudinal axis of the hollow tubular base element of the aerosol generating substrate is preferably capable of being aligned with the central longitudinal axis of the hollow tubular element of the downstream section. For example, when 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, the central longitudinal axis of the hollow tubular base element can be aligned with the central longitudinal axis of the hollow tubular element of the downstream section such that the cavities of the hollow tubular base element and the hollow tubular element of the downstream section are substantially aligned.

[0194] The hollow tubular element of the downstream section may include a paper-based material. The hollow tubular element may include at least one layer of paper. The paper may be very stiff paper. The paper may be crimped paper such as heat-resistant crimped paper or crimped sulfuric acid paper.

[0195] Preferably, the hollow tubular element may include cardboard. The hollow tubular element may be a cardboard tube. The hollow tubular element may be formed from cardboard. Advantageously, cardboard provides a balance between being deformable to facilitate the insertion of the aerosol article into the aerosol generating device and being sufficiently rigid to provide a suitable engagement of the article with the interior of the device, and is a cost-effective material. Thus, the cardboard tube may provide adequate resistance to deformation or compression during use.

[0196] The hollow tubular element of the downstream section may be a paper tube. The hollow tubular element may be a tube formed from spirally wound paper. The hollow tubular element may be formed from a plurality of layers of paper. The paper may 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.

[0197] The hollow tubular element of the downstream section may include a polymer material. For example, the hollow tubular element may include a polymer film. The polymer film may include a cellulose film. The hollow tubular segment may include low density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. The hollow tubular element may also include cellulose acetate tow.

[0198] When the hollow tubular element includes cellulose acetate tow, the cellulose acetate tow may have a denier per filament of about 2 to about 4 and a total denier of about 25 to about 40.

[0199] 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.

[0200] The aerosol generating article according to the present disclosure may comprise a ventilation zone at a position along the downstream section. More specifically, when the downstream section comprises a hollow tubular element, the ventilation zone may be provided at a position along the hollow tubular element.

[0201] Thus, a vented cavity is provided downstream of the rod of the aerosol generating substrate. This provides particularly efficient cooling of the aerosol and can promote improved nucleation of aerosol particles.

[0202] The ventilation zone may typically include a plurality of perforations through the peripheral wall of the hollow tubular element. The plurality of perforations of the ventilation zone may also 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 include 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 includes 8 to 30 perforations.

[0203] 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.

[0204] Providing a mouthpiece element at the downstream end of the aerosol generating article according to the present disclosure can provide an attractive appearance and feel for the consumer.

[0205] 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.

[0206] The fibrous filter material may be for filtering aerosol generated from an 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.

[0207] 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 contact with each other end-to-end.

[0208] The downstream section may have a mouth-side end cavity at the downstream end 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, the outer wrapper extending downstream 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.

[0209] 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.

[0210] Preferably, the mouthpiece element, or its mouthpiece filter segments, has a low particle filtration efficiency.

[0211] 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.

[0212] 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 mouthpiece filter segment) can 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 can be about 7.2 mm plus or minus 10 percent.

[0213] The diameter of the mouthpiece element can be from about 5 mm to about 10 mm. The diameter of the mouthpiece element can be from about 5.5 mm to about 9 mm. The diameter of the mouthpiece element can be from about 6 mm to about 8 mm. The diameter of the mouthpiece element can be about 7.2 mm ± 10 percent. The diameter of the mouthpiece element can be about 7.25 mm ± 10 percent.

[0214] Unless otherwise specified, the draw resistance (RTD) of a component or aerosol generating article is measured in accordance with ISO6565-2015. 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 can also refer to "resistance to draw".

[0215] 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.

[0216] 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.

[0217] The extraction resistance of the downstream section can be about 0 mmH2O or more and less than about 12 mmH2O. Preferably, the extraction resistance of the downstream section can be about 3 mmH2O or more and less than about 12 mmH2O. The extraction resistance of the downstream section can be about 0 mmH2O or more and less than about 11 mmH2O. Even more preferably, the extraction resistance of the downstream section can be about 3 mmH2O or more and less than about 11 mmH2O. Even more preferably, the extraction resistance of the downstream section can be about 6 mmH2O or more and less than about 10 mmH2O. Preferably, the extraction resistance of the downstream section can be about 8 mmH2O.

[0218] The extraction resistance (RTD) characteristics of the downstream section may, in whole or in part, be 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.

[0219] The extraction 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.

[0220] 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.

[0221] The draw resistance of the mouthpiece element can be about 0 mmH2O or more and less than about 12 mmH2O. Preferably, the draw resistance of the mouthpiece element can be about 3 mmH2O or more and less than about 12 mmH2O. The draw resistance of the mouthpiece element can be about 0 mmH2O or more and less than about 11 mmH2O. Even more preferably, the draw resistance of the mouthpiece element can be about 3 mmH2O or more and less than about 11 mmH2O. Even more preferably, the draw resistance of the mouthpiece element can be about 6 mmH2O or more and less than about 10 mmH2O. Preferably, the draw resistance of the mouthpiece element can be about 8 mmH2O.

[0222] 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 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.

[0223] 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 that provide suitable RTD characteristics.

[0224] The mouthpiece element can be formed from a suitable material sheet that is crimped, pleated, assembled, woven, or folded into an element that defines a plurality of channels extending in the major axis direction. Such a sheet of suitable material can be formed of paper, cardboard, polymers such as polylactic acid, or any other cellulose-based, paper-based, or bioplastic-based material. The cross-sectional profile of such a mouthpiece element may exhibit channels oriented randomly.

[0225] 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 major axis direction. The tubes extending in the major axis direction can be formed of polylactic acid. The mouthpiece element can be formed by extrusion, 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.

[0226] 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.

[0227] 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.

[0228] 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.

[0229] For example, the ratio of the length of the mouthpiece element to the length of the downstream section is from about 0.03 to about 0.35, preferably from about 0.05 to about 0.30, more preferably from about 0.1 to about 0.25.

[0230] The ratio of the length of the mouthpiece element to the overall 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 overall 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 overall length of the aerosol-generating article can be about 0.1 or less.

[0231] The ratio of the length of the mouthpiece element to the overall 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 overall 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 overall length of the aerosol-generating article can be at least about 0.05.

[0232] For example, the ratio of the length of the mouthpiece element to the overall length of the aerosol-generating article is from about 0.01 to about 0.2, preferably from about 0.02 to about 0.15, more preferably from about 0.05 to about 0.1.

[0233] 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.

[0234] 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.

[0235] 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.

[0236] 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.

[0237] 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.

[0238] For example, the downstream section can have a total length of 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.

[0239] 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.

[0240] The ratio of the length of the downstream section to the overall 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 overall 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 overall 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 overall length of the aerosol-generating article can be at least about 0.60.

[0241] Preferably, the overall length of the aerosol-generating article according to the present invention is at least about 35 millimeters. More preferably, the overall length of the aerosol-generating article according to the present invention is at least about 40 millimeters. Even more preferably, the overall length of the aerosol-generating article according to the present invention is at least about 45 millimeters. Even more preferably, the overall length of the aerosol-generating article according to the present invention is at least about 50 millimeters.

[0242] Preferably, the overall length of the aerosol-generating article according to the present invention is 110 millimeters or less. More preferably, the overall length of the aerosol-generating article according to the present invention is preferably 100 millimeters or less. Even more preferably, the overall length of the aerosol-generating article according to the present invention is preferably 75 millimeters or less. Even more preferably, the overall length of the aerosol-generating article according to the present invention is preferably 70 millimeters or less.

[0243] 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.

[0244] 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.

[0245] The aerosol generating article preferably has an outer diameter of about 10 millimeters or less. The aerosol generating article more preferably has an outer diameter of about 9 millimeters or less. The aerosol generating article even more preferably has an outer diameter of about 8 millimeters or less.

[0246] For example, the aerosol generating article can have an outer diameter of 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.

[0247] The outer diameter of the aerosol generating article can be substantially constant over the entire length of the article. Alternatively, different portions of the aerosol generating article can have different outer diameters.

[0248] One or more of the components of the aerosol generating article may be individually surrounded by their own wrapper.

[0249] The aerosol generating substrate and the downstream section are preferably combined together with a wrapper such as a tipping wrapper.

[0250] The components of the aerosol generating article according to the present disclosure are preferably made from biodegradable materials.

[0251] Preferably, the aerosol generating article according to the 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 may also comprise 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 is transmitted from the susceptor to the aerosol generating substrate mainly by conduction. Examples of electrically operated aerosol generating systems having an aerosol generating article with an induction heating device and a susceptor are described in WO-A1-95 / 27411 and WO-A1-2015 / 177255.

[0252] The present disclosure relates to an aerosol generating system comprising an aerosol generating device having a distal end and a mouthpiece end. The aerosol generating device may comprise a body or housing. The body or housing of the aerosol generating device may define a device cavity or heating chamber for removably receiving the aerosol generating article at the mouthpiece end of the device. 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.

[0253] In other words, the aerosol generating device may comprise a heating chamber for receiving the aerosol generating article and a heating element provided around or surrounding the heating chamber.

[0254] 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 within or in the device or 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 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 via the open end of the device or the device cavity. The device cavity may be cylindrical so as to conform to the same shape of the aerosol generating article.

[0255] The expression "received within" may refer to the fact that a component or element is received, either fully or partially, within another component or element. For example, the expression "the aerosol generating article is received within the device cavity" refers to the fact that the aerosol generating article is received, either fully 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.

[0256] When received within a device or a device cavity (or heating chamber), the aerosol-generating article may be configured to protrude 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 heating chamber). This facilitates the insertion and removal of the article from the device, and enables the mouth-side end portion of the article from which the user can draw the aerosol to extend beyond the device.

[0257] The length of the device cavity may be from about 15 millimeters to about 80 millimeters. The length of the device cavity is preferably from about 20 millimeters to about 70 millimeters. The length of the device cavity is more preferably from about 25 millimeters to about 60 millimeters. The length of the device is more preferably from about 25 millimeters to about 50 millimeters.

[0258] The length of the device cavity may be from about 25 millimeters to about 29 millimeters. The length of the device cavity is preferably from about 25 millimeters to about 29 millimeters. The length of the device cavity is more preferably from about 26 millimeters to about 29 millimeters. The length of the device cavity is still more preferably about 27 millimeters or about 28 millimeters.

[0259] 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.

[0260] 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 to establish a tight fit therewith.

[0261] The device cavity can be configured to establish a tight fit with the aerosol-generating article received within the device cavity. The tight fit can refer to a slip fit. The aerosol-generating device can comprise a peripheral wall. Such a peripheral wall can define the device cavity or the heating chamber. The peripheral wall defining the device cavity can 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.

[0262] Such an airtight fit can 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 can be established along the entire length of the device cavity or along a portion of the length of the device cavity.

[0263] The aerosol-generating device can comprise an air intake channel extending between a channel inlet and a channel outlet. The air intake channel can be configured to establish 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 can be defined within the housing of the aerosol-generating device to enable fluid communication between the interior of the device cavity and the exterior of the aerosol-generating device. When the aerosol-generating article is received within the device cavity, the air intake channel can be configured to provide air flowing into the article to deliver the generated aerosol to the user drawing it out from the mouth-side end of the article.

[0264] The air intake channel of the aerosol generating device may be within or defined by the peripheral wall of the housing of the aerosol generating device. 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.

[0265] 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.

[0266] 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 be such that a fluid communication is established 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 sucking the inserted aerosol generating article, 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.

[0267] The heater may be any suitable type of heater. In the present disclosure, the heater is preferably an external heater.

[0268] 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 from both. The heating element may be a heater blade or pin adapted to be inserted into the aerosol generating substrate such that the substrate is heated from the inside. Preferably, the heating element surrounds the substrate partially or completely and can externally heat the substrate circumferentially from the outside.

[0269] Preferably, the heater may externally heat the aerosol generating article when received within the aerosol generating device. Such an external heater may surround 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.

[0270] The heater may be arranged to heat the outer surface of the aerosol generating substrate. The heater may be arranged for insertion into the aerosol generating substrate when the aerosol generating substrate is received within a cavity. The heater may be positioned within the device cavity or heating chamber.

[0271] 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 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.

[0272] The heater may include an induction heating arrangement. The induction heating arrangement includes an induction source and a susceptor, which may be provided outside the aerosol generating substrate or inside the aerosol generating substrate. The induction source may include an inductor coil and a power supply configured to provide a high-frequency oscillating current to the inductor coil. As used herein, the high-frequency oscillating current means an oscillating current having a frequency of about 500 kHz to about 30 MHz. Advantageously, the heater may include a DC / AC inverter for converting a DC current supplied by a DC power supply into an AC current. The inductor coil may be arranged to generate a high-frequency oscillating electromagnetic field when receiving the high-frequency oscillating current from the power supply. The inductor coil may 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 at least partially extend along the length of the device cavity.

[0273] The heater may include an induction heating element. The induction heating element may be a susceptor element. As used herein, the term "susceptor element" refers to an element including a material having the ability to convert electromagnetic energy into heat. When the susceptor element is located within an alternating electromagnetic field, the susceptor is heated. The heating of the susceptor element may be the result of at least one of hysteresis losses and eddy currents induced within the susceptor, depending on the electrical and magnetic properties of the susceptor material.

[0274] The susceptor element may be arranged such that when the aerosol generating article is received within the cavity of the aerosol generating device, the oscillating electromagnetic field generated by the inductor coil induces a current within the susceptor element 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. An 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.

[0275] The susceptor element can be positioned in contact with the aerosol generating substrate. The susceptor element may be located within the aerosol generating device. The susceptor element may be located around or adjacent to 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 externally heat the aerosol generating substrate. The susceptor element can surround the aerosol generating article when housed within the heating chamber.

[0276] 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 include 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 aluminum or can include aluminum. The susceptor element preferably contains more than about 5 percent ferromagnetic or paramagnetic material, more preferably more than 20 percent ferromagnetic or paramagnetic material, and even more preferably more than 50 percent or more than 90 percent ferromagnetic or paramagnetic material. Some elongate susceptor elements can be heated to a temperature in excess of 250 degrees Celsius.

[0277] The susceptor element can comprise a non-metallic core having a metal layer disposed thereon. For example, the susceptor element can include a metal track formed on the outer surface of a ceramic core or substrate.

[0278] 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.

[0279] 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°C to about 300°C. The operating temperature range of the heater may be from about 150°C to about 250°C.

[0280] Preferably, the operating temperature range of the heater may be between about 150°C and about 200°C. More preferably, the operating temperature range of the heater may be from about 180°C to about 200°C. 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 of H2O), an aerosol generating device with an external heater having an operating temperature range of from about 180°C to about 200°C, it has been found that optimal and consistent aerosol delivery can be achieved.

[0281] 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 generating system intended to be used to heat the aerosol generating article. Thereby, it is ensured that the hollow tubular substrate element is heated substantially along its entire length, and as a result, the generation of aerosol from the aerosol generating substrate can be maximized.

[0282] The aerosol generating device may be provided with 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 allow for continuous heating of the aerosol generation 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 allow for a predetermined number of smoking sessions, or discontinuous activation of the heater.

[0283] The aerosol generating article 1 shown in FIG. 1 comprises a rod of the aerosol generation substrate 12 and a downstream section 14 provided downstream of the rod of the aerosol generation substrate 12. The aerosol generating article 1 extends from an upstream or distal end 16 that coincides with the upstream end of the aerosol generation 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 components such as a hollow tubular element or a mouthpiece element as described within the present disclosure.

[0284] The aerosol generating article 1 has an outer diameter of about 7.25 mm.

[0285] The aerosol generating substrate 12 includes a hollow tubular substrate element 40 formed of a homogenized tobacco material. The hollow tubular substrate element 40 has a peripheral wall 42 defining a longitudinal cavity 44 that provides 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.

[0286] 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.

[0287] The aerosol generating article 1 further comprises an air flow guiding element 20 extending from an upstream position into the longitudinal substrate cavity 44. The air flow guiding element 20 includes an elongated body in the form of a hollow tube having a uniform outer diameter and a closed downstream end. The length of the air flow guiding element 20 is about 10 mm. The outer diameter of the air flow guiding element 20 is about 3 mm. The air flow guiding element 20 is made of or includes cardboard.

[0288] The aerosol generating article 1 also comprises an upstream section 30 provided upstream of the aerosol generating substrate 12. In the aerosol generating article 1, the upstream section 30 includes a base support element 32. The base support element 32 has the same outer diameter as the aerosol generating substrate 12. The downstream end of the base support element 32 abuts the upstream end of the aerosol generating substrate 12. The upstream end 16 is defined by the upstream end of the base support element 32. The base support element 32 includes a porous material such as cellulose acetate to enable fluid communication between the exterior of the aerosol generating article 1 and the substrate cavity 44.

[0289] The airflow guiding element 20 is coupled to the base support element 32 and extends downstream therefrom. Thus, the upstream end of the airflow guiding element 20 is coupled to the base support element 32, while the downstream end of the airflow guiding element 20 defines a free end, as shown in FIG. 1. The length of the base support element is approximately 1 mm.

[0290] The annular airflow channel 22 is defined between the inner surface of the hollow aerosol generating substrate 12 and the outer surface of the airflow guiding element 20. As the user sucks on the mouth-side end 18 of the aerosol generating article 1, air can be drawn through the base support element 32 and through the upstream end 16. The air then flows through the annular airflow channel 22 and can proceed towards the downstream end 18 of the article 1.

[0291] FIG. 2 shows a cross-section of the aerosol generating article 1 at a position between the upstream and downstream ends of the airflow guiding element 20. The wall thickness of the hollow tubular substrate element 40 is approximately 1 mm. The thickness of the annular airflow channel 22 is approximately 1.13 mm.

[0292] FIG. 3 illustrates another embodiment of the aerosol generating article 1 with the downstream end of the airflow guiding element 20 open. This defines a secondary airflow channel 24 extending from the upstream end to the downstream end of the airflow guiding element. Air can flow through the porous base support element 32, enter the empty longitudinal cavity defined by the hollow tube of the airflow guiding element 20, and exit through its open downstream end. The inner diameter of the airflow guiding element 20 shown in FIG. 3 is approximately 1.5 mm. The inner diameter of the airflow guiding element 20 shown in FIG. 3 defines the diameter of the secondary airflow channel 24. The airflow guiding element 20 is made of or includes cardboard.

[0293] FIG. 4 shows another embodiment of the aerosol generating article 2. The aerosol generating article 2 differs from the aerosol generating article 1 shown in FIG. 1 in that the base support element 32 is held within the cavity of the hollow upstream element 34 and the airflow guiding element 201 has a different configuration. The upstream section 30 includes an upstream element 34 in the form of a hollow tubular element that defines an empty longitudinal cavity extending along its entire length. The upstream element 34 abuts the aerosol generating substrate 12.

[0294] The outer diameter of the base support element 32 is sized such that the base support element 32 is held within the upstream element 34. In other words, the base support element 32 establishes a tight fit with the inner wall of the upstream element 34. The base support element 34 extends transversely across the entire cavity defined by the upstream element 34. The downstream end of the base support element 32 is aligned with the upstream end of the upstream element 34. The length of the base support element 32 is approximately 1.5 mm. The length of the hollow upstream element 34 is approximately 5 mm. In the embodiment of FIG. 4, the outer diameter and inner diameter of the upstream element 34 are the same as the outer diameter and inner diameter of the aerosol generating element 12 located immediately downstream.

[0295] The airflow guiding element 201 includes an irregular outer surface such that the outer diameter of the airflow guiding element 201 varies along its length. An annular airflow channel 22 is similarly defined around the airflow guiding element 201. The airflow guiding element 201 includes an elongated core portion 21 and a plurality of extension portions 23 extending radially outward from the elongated core portion 21. The airflow guiding element 201 includes two extension portions 23. The first extension portion 23 is positioned at the free downstream end of the airflow guiding element 201, and the second extension portion 23 is positioned immediately upstream of the first extension portion 23. The extension portions 23 are spherical in shape. The airflow guiding element 201 is made of or includes cardboard.

[0296] The length of the airflow guiding element 201 is approximately 8 mm. The maximum outer diameter or width of the airflow guiding element 201 is approximately 3 mm. The minimum outer diameter or width of the airflow guiding element 201 is approximately 1 mm. 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.

[0297] FIG. 5 shows another embodiment of the aerosol-generating article 3. The aerosol-generating article 3 is different from the aerosol-generating article 1 shown in FIG. 1 in that the airflow guiding element 202 has a different configuration. The airflow guiding element 202 includes an irregular outer surface such that the outer diameter of the airflow guiding element 202 varies along its length and an annular airflow channel 22 is defined around the airflow guiding element 202. The airflow guiding element 202 includes an elongated core portion 21 and a plurality of extension portions 231, 232 extending radially outward from the elongated core portion 21. The airflow guiding element 202 includes three extension portions 231, 232. The first extension portion 231 is located at the fixed upstream end of the airflow guiding element 202 and is hemispherical in shape. The upstream end of the first extension portion 231 is flat and is coupled to the downstream end of the base support element 32. As shown in FIG. 5, downstream of the first extension portion 231 are two successively arranged spherical extension portions 232. One of the extension portions 232 is positioned at the free downstream end of the airflow guiding element 202 and the other is positioned immediately upstream thereof, between the extension portion 232 and the other extension portion 231.

[0298] The airflow guiding element 202 is made of or includes cardboard.

[0299] The length of the airflow guiding element 202 is about 8 mm. The maximum outer diameter or width of the airflow guiding element 202 is about 3 mm. The minimum outer diameter or width of the airflow guiding element 202 is about 1 mm. The maximum thickness of the airflow channel 22 is about 1.13 mm and the minimum thickness of the airflow channel 22 is about 2.13 mm.

[0300] Figure 6 shows another embodiment of the aerosol-generating article 4. The aerosol-generating article 4 is different from the aerosol-generating article 1 shown in Figure 1 in that the airflow guiding element 203 has a different configuration. The airflow guiding element 203 includes 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 233. 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 233 are spaced apart from the upstream and downstream ends of the airflow guiding element 203, respectively.

[0301] The airflow guiding element 203 is made of or includes cardboard.

[0302] 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. The maximum thickness of the airflow channel 22 is about 1.13 mm, and the minimum thickness of the airflow channel 22 is about 2.13 mm.

[0303] Figure 7 illustrates an aerosol-generating system 10 comprising an exemplary aerosol-generating device 100 configured to receive any one of the aerosol-generating articles described in the present disclosure. In Figure 7, the aerosol-generating article is the aerosol-generating article 2 shown in Figure 4.

[0304] Figure 7 illustrates the mouth-side end portion downstream of the aerosol generating device 100 where the device cavity (or heating chamber) is defined and the aerosol generating article can be received. The aerosol generating device 100 includes a housing (or body) 104 that extends between a mouth-side end 102 and a distal end (not shown). The housing 104 includes a peripheral wall 106. The peripheral wall 106 defines a device cavity for receiving the aerosol generating article 2. The device cavity is defined by a closed distal end and an open mouth-side end. The mouth-side end of the device cavity is located at the mouth-side end of the aerosol generating device 100. The aerosol generating article 2 is configured to be received through the mouth-side end of the device cavity and held within the device cavity. The aerosol generating device 100 is configured such that air enters the device cavity during use, through its upstream end 16, into the device cavity, and into the aerosol generating article.

[0305] The aerosol generating device 100 further includes a heater 110 and a power source (not shown) for supplying power to the heater. 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 2 is received within the device 100. The heater 110 is disposed to externally heat the aerosol generating substrate 12 of the aerosol generating article 2 during use.

[0306] FIG. 8 illustrates an aerosol-generating article 5 that is different from the aerosol-generating article 3 shown in FIG. 5 in that it is not configured to be inserted into and heated in a separate heating device. Instead, the upstream section 30 of the aerosol-generating article 4 includes a combustible heat source 34 and a thermally conductive element 36 that is located between and in direct contact with the heat source 34 and the aerosol-generating substrate 36. The heat source 34 defines the upstream end 16 of the aerosol-generating article 5. The aerosol-generating substrate 12 includes at least one perforation 46 for providing an air inlet into the substrate cavity 44. In use, the combustible heat source 34 is ignited and air is drawn into the substrate cavity 44 through the air inlet provided by the perforation 46 and can be drawn downstream towards the mouth-side end 18 of the article 5. Heat is configured to be transferred from the heat source 4 to the aerosol-generating substrate 12 by conduction through the thermally conductive element 36. Further, the thermally conductive element 36 acts as a base support element for the airflow guiding element 202. In other words, the upstream end of the airflow guiding element 202 is coupled to the downstream end or downstream surface of the thermally conductive element 36.

[0307] The thermally conductive element 36 includes a thermally conductive wall 361 located between the heat source 34 and the aerosol-generating substrate 36, and two sleeve portions 362, 363. The upstream sleeve portion 362 extends upstream from the periphery of the thermally conductive wall 361 and is arranged to hold the downstream or proximal portion of the heat source 34 in contact with the thermally conductive wall 361. The downstream sleeve portion 363 extends downstream from the periphery of the thermally conductive wall 361 and is arranged to hold the upstream or distal portion of the aerosol-generating substrate 12 in contact with the thermally conductive wall 361. The aerosol-generating article 5 includes an airflow guiding element 204 that has the same shape and size as the airflow guiding element 202 of the aerosol-generating article 4. Instead of or in addition to cardboard, the airflow guiding element 204 can include a thermally conductive material such as aluminum. Both the thermally conductive wall 361 and the airflow guiding element 204 may include the same thermally conductive material.

[0308] In all of the figures of the present disclosure, the airflow path, aerosol flow path, or other fluid path into and through the aerosol-generating article during use is indicated by discontinuous arrows.

[0309] For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like are to be understood as being modified in all instances by the term "about." Also, all ranges include the disclosed maximum and minimum points, as well as any intermediate ranges therebetween, whether or not specifically enumerated herein. Thus, in this context, the number A is understood to be A ± 10%. Within this context, the number A may also be considered to include numerical values within the general standard error of the measurement of the property being modified by the number A. The number A may deviate by the percentages recited above in some instances where 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, as well as any intermediate ranges therebetween, whether or not specifically enumerated herein.

Examples

[0310] The following is a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more of the features of another example, embodiment, or aspect described herein.

[0311] Example 1. An aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article comprising 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. Example 2. The aerosol-generating article according to Example 1, further comprising an air-flow guiding element, the air-flow guiding element extending in the longitudinal direction within the substrate cavity. Example 3. The aerosol generating article according to Example 2, wherein an air flow channel is defined between an outer surface of the air flow guiding element and an inner surface of the aerosol generating substrate. Example 4. The aerosol generating article according to Example 2 or 3, wherein a width or diameter of the air flow guiding element is smaller than a diameter of the substrate cavity. Example 5. The aerosol generating article according to any one of Examples 2 to 4, further comprising an upstream section located upstream of the aerosol generating substrate, the upstream section including an upstream element adjacent to an upstream end of the aerosol generating substrate, and the air flow guiding element being coupled to or held by the upstream element. Example 6. The aerosol generating article according to any one of Examples 2 to 5, wherein a width or diameter of the air flow guiding element varies along its length. Example 7. The aerosol generating article according to any one of Examples 2 to 6, wherein a part of the air flow guiding element contacts a part of the aerosol generating substrate. Example 8. The aerosol generating article according to any one of Examples 2 to 7, wherein a part of the air flow guiding element has a width or diameter substantially corresponding to a diameter of the substrate cavity. Example 9. The aerosol generating article according to any one of Examples 2 to 8, wherein the air flow guiding element extends along at least 25 percent of a length of the substrate cavity. Example 10. The aerosol generating article according to any one of Examples 2 to 9, wherein the air flow guiding element extends along at least 50 percent of a length of the substrate cavity. Example 11. The aerosol generating article according to any one of Examples 2 to 10, wherein the air flow guiding element extends along at least 60 percent of a length of the substrate cavity. Example 12. The aerosol generating article according to any one of Examples 2 to 11, wherein the air flow 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. Example 13. The aerosol generating article according to embodiment 12, wherein the extension part is shaped substantially in the form of a hemisphere, a sphere, a cylinder, a cone, or a ring. Embodiment 14. The aerosol generating article according to embodiment 12 or 13, wherein the core part is shaped substantially in the form of a rod, a tube, or a cone. Embodiment 15. The aerosol generating article according to any one of embodiments 12 to 14, wherein the airflow guiding element includes at least two extension parts located along the core part. Embodiment 16. The aerosol generating article according to any one of embodiments 12 to 14, wherein the airflow guiding element includes at least two extension parts each located at a different position along the core part. Embodiment 17. The aerosol generating article according to any one of embodiments 2 to 16, wherein the airflow guiding element includes a hollow tube. Embodiment 18. The aerosol generating article according to any one of embodiments 2 to 17, further comprising a base support element, wherein the airflow guiding element extends from the base support element. Embodiment 19. The aerosol generating article according to embodiment 18, wherein the base support element is located upstream of the rod of the aerosol generating substrate. Embodiment 20. The aerosol generating article according to embodiment 18 or 19, wherein the base support element is located within the upstream section or the upstream element of the aerosol generating article. Embodiment 21. The aerosol generating article according to embodiment 18 or 19, wherein the base support element is held within the upstream element of the aerosol generating article. Embodiment 22. The aerosol generating article according to any one of embodiments 18 to 21, wherein the base support element is porous or includes at least one opening such that fluid communication is established between the outside of the aerosol generating article and the inside of the aerosol generating substrate. Embodiment 23. The aerosol generating article according to any one of Examples 2 to 22, wherein the outer surface in the major axis direction of the airflow guiding element and the inner surface in the major axis direction of the aerosol generating substrate define an airflow channel. Example 24. The aerosol generating article according to Example 5, wherein the upstream element includes a solid plug segment. Example 25. The aerosol generating article according to Example 5, wherein the upstream element includes a hollow tubular segment. Example 26. The aerosol generating article according to any one of Examples 2 to 25, 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 along the inside of the airflow guiding element. Example 27. The aerosol generating article according to any one of Examples 2 to 26, further comprising a downstream section located downstream of the aerosol generating substrate, the downstream section including one or more of a mouthpiece element and a hollow tubular element. Example 28. The aerosol generating article according to Example 27, wherein the mouthpiece element includes at least one mouthpiece filter segment formed of a fibrous filter material. Example 29. The aerosol generating article according to any one of Examples 1 to 28, wherein the aerosol generating substrate has a length of 5 millimeters to 30 millimeters. Example 30. The aerosol generating article according to any one of Examples 1 to 29, wherein the aerosol generating substrate has a length of 5 millimeters to 16 millimeters. Example 31. The aerosol generating article according to any one of Examples 1 to 30, wherein the wall thickness of the aerosol forming substrate is 5 percent to 40 percent of the outer diameter of the aerosol generating substrate. Example 32. The aerosol generating article according to any one of Examples 1 to 31, wherein the wall thickness of the aerosol generating substrate is at least 200 micrometers. Example 33. An aerosol-generating article according to any one of Examples 1 to 32, wherein the aerosol-generating substrate comprises a homogenized tobacco material. Example 34. An aerosol-generating article according to any one of Examples 1 to 33, wherein the aerosol-generating substrate is formed from a plurality of overlapping sheets of homogenized tobacco material. Example 35. An aerosol-generating article according to any one of Examples 1 to 36, wherein the aerosol-generating substrate comprises one or more aerosol-forming substances, and the content of the aerosol-forming substances in the aerosol-generating substrate is 10 wt% to 20 wt% on a dry weight basis. Example 36. An aerosol-generating article according to any one of Examples 2 to 35, wherein a portion of the airflow guiding element is coated with one or more of a further aerosol-generating substrate, a flavorant, and an aerosol-forming substance. Example 37. An aerosol-generating article according to Example 35 or 36, wherein the aerosol-forming substance comprises one or more of glycerin and propylene glycol. Example 38. An aerosol-generating article according to any one of Examples 2 to 37, wherein the maximum width or diameter of a portion of the airflow guiding element extending into the substrate cavity is at least about 25% of the diameter of the substrate cavity. Example 39. An aerosol-generating article according to any one of Examples 2 to 37, wherein the maximum width or diameter of a portion of the airflow guiding element extending into the substrate cavity is at least 50% of the diameter of the substrate cavity. Example 40. An aerosol-generating article according to any one of Examples 2 to 37, wherein the maximum width or diameter of a portion of the airflow guiding element extending into the substrate cavity is at least about 75% of the diameter of the substrate cavity. Example 41. An aerosol-generating article according to any one of Examples 2 to 40, wherein the outer surface of the airflow guiding element is textured. Example 42. An aerosol generating system comprising: an aerosol generating article according to any one of Examples 1 to 41; and an aerosol generating device including a heating chamber for receiving the aerosol generating article and a heating element provided around or adjacent to the heating chamber.

[0312] The specific embodiments and examples described above illustrate, but do not limit, the present invention. Other embodiments of the present invention may be made, and it is understood that the specific embodiments and examples described herein are not exhaustive.

Claims

1. An aerosol generating article for generating an inhalable aerosol upon heating, wherein the aerosol generating article is An aerosol generating substrate, wherein the aerosol generating substrate is in the form of a hollow tubular segment defining a substrate cavity extending from the upstream end to the downstream end of the aerosol generating substrate, An upstream section located upstream of the aerosol generating substrate, wherein the upstream section includes an upstream element adjacent to the upstream end of the aerosol generating substrate, An aerosol generating article comprising an airflow guide element, wherein the airflow guide element is coupled to the upstream element, extends in the longitudinal direction within the substrate cavity, and defines an airflow channel between the outer surface of the airflow guide element and the inner surface of the aerosol generating substrate.

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

3. The aerosol generating article according to claim 1, wherein the width or diameter of the airflow guide element changes along its length.

4. The aerosol generating article according to claim 1, wherein the outer surface of the airflow guide element is textured or has an uneven surface.

5. The aerosol generating article according to claim 1, wherein the airflow guide element extends along at least 50 percent of the length of the substrate cavity.

6. The aerosol generating article according to claim 1, wherein the airflow guide element includes a hollow tube.

7. The aerosol generating article according to claim 1, wherein the airflow guide element comprises an elongated body including a central core portion and an extension portion positioned along the central core portion, the extension portion extending outward from the central core portion.

8. The aerosol generating article according to claim 7, wherein the airflow guide element includes at least two extensions located along the central core portion.

9. The aerosol generating article according to claim 1, further comprising a base support element located upstream of the aerosol generating substrate, wherein the airflow guide element extends from the base support element.

10. The aerosol generating article according to claim 9, wherein the base support element is porous or includes at least one opening so that fluid communication is established between the outside of the aerosol generating article and the inside of the aerosol generating substrate via the base support element.

11. The aerosol generating article according to claim 1, wherein the airflow guide 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 therewith within the airflow guide element.

12. The aerosol generating article according to claim 1, wherein the wall thickness of the aerosol generating substrate is 5 percent to 40 percent of the outer diameter of the aerosol generating substrate.

13. The aerosol generating article according to claim 1, wherein the maximum width or diameter of a 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 article according to claim 1, wherein the airflow guide element does not come into contact with the inner surface of the aerosol generating substrate.

15. An aerosol generating system comprising an aerosol generating article according to any one of claims 1 to 14, and an aerosol generating device including a heating chamber for receiving the aerosol generating article and a heating element provided around or near the heating chamber.

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