CN119255718A

CN119255718A - Aerosol-generating article comprising an airflow directing element extending into a tubular substrate

Info

Publication number: CN119255718A
Application number: CN202380042510.2A
Authority: CN
Inventors: G·坎皮特利
Original assignee: Philip Morris Products SA
Current assignee: Philip Morris Products SA
Priority date: 2022-06-30
Filing date: 2023-06-30
Publication date: 2025-01-03
Also published as: JP2025521638A; WO2024003397A1; KR20250026843A; EP4547048A1; US20250280872A1

Abstract

An aerosol generating article (1, 2, 3, 4, 5) for generating an inhalable aerosol when heated is provided. The aerosol generating article comprises an aerosol generating substrate (40) in the form of a hollow tubular segment defining 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 directing element (20) extending longitudinally into the substrate cavity and defining an airflow channel (22) between an outer surface of the airflow directing element and an inner surface of the aerosol generating substrate. The width or diameter of the airflow directing element is less than the diameter of the substrate cavity.

Description

Aerosol-generating article comprising an airflow directing element extending into a tubular substrate

The present invention relates to an aerosol-generating article comprising a strip of aerosol-generating substrate adapted to produce an inhalable aerosol upon heating.

Aerosol-generating articles in which an aerosol-generating substrate, such as a tobacco-containing substrate, is heated rather than combusted are known in the art. Generally, in such heated smoking articles, an aerosol is generated by transferring heat from a heat source to a physically separate aerosol-generating substrate or material that may be positioned in contact with, inside, around or downstream of the heat source. During use of the aerosol-generating article, volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source and entrained in air drawn through the aerosol-generating article. As the released compound cools, the compound condenses to form an aerosol.

A number of prior art documents disclose aerosol-generating devices for consuming aerosol-generating articles. Such devices include, for example, electrically heated aerosol-generating devices in which an aerosol is generated by transferring heat from one or more electric heater elements of the aerosol-generating device to an aerosol-generating substrate of a heated aerosol-generating article. For example, electrically heated aerosol-generating devices have been proposed which comprise an internal heater blade adapted to be inserted into an aerosol-generating substrate. It is also known to use aerosol-generating articles in combination with external heating systems. For example, WO-up>A-2020/115151 describes the provision of external heating elements arranged around the periphery of an aerosol-generating article when the aerosol-generating article is received in up>A cavity of an aerosol-generating device. As an alternative WO-up>A-2015/176898 proposes an inductively heatable aerosol-generating article comprising an aerosol-generating substrate and up>A susceptor arranged within the aerosol-generating substrate.

In general, it may be difficult to provide efficient heating of the aerosol-generating substrate across the entire strip of the substrate. The portion of the substrate closest to the heating element will inevitably be heated most effectively, while imperfect transfer of heat through the substrate will mean that the portion of the substrate furthest from the heating element may not be heated effectively. Thus, aerosol generation from those portions of the substrate that are not effectively heated is not optimal, and in some cases, portions of the substrate may not reach sufficiently high temperatures at all during use to generate an aerosol. For example, in the case of using an external heating element to heat a strip of aerosol-generating substrate, as described above, the central portion of the strip of aerosol-generating substrate is less likely to generate as much aerosol as the outer portion of the strip, and in some cases may not generate any aerosol. In summary, aerosol generation from an aerosol-generating rod may thus be inefficient, wherein a portion of the aerosol-generating substrate may be wasted.

In addition, aerosol-generating substrates typically do not immediately generate an aerosol upon activation of the heating element. This is because there is a pre-heating time after activation of the heating element during which the aerosol-generating substrate is heated to the temperature required for aerosol generation. Thus, there may be a relatively long duration between activating the heating element and generating the organoleptically acceptable aerosol for inhalation by the user.

It is therefore desirable to provide an aerosol-generating article having an aerosol-generating substrate which is adapted to provide more efficient aerosolization of the aerosol-generating substrate and to reduce wastage of substrate material such as tobacco. It is also desirable to provide an aerosol-generating article that may achieve a relatively short warm-up time such that a sensorially acceptable aerosol may be delivered to a user shortly after starting heating the aerosol-generating substrate. It is also desirable to provide an aerosol-generating article that can provide optimized aerosol delivery from an aerosol-generating substrate. It is particularly desirable to provide an aerosol-generating article having a relatively simple design such that it can be manufactured and incorporated into existing product designs in a cost-effective manner. It is also desirable to provide an article that can be easily adapted such that it can be heated in various types of heating devices, including induction heating devices and resistive heating devices.

The present invention provides an aerosol-generating article for generating an inhalable aerosol upon heating. The aerosol-generating article may comprise an aerosol-generating substrate. The aerosol-generating substrate may be in the form of a hollow tubular section defining 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 may comprise an airflow directing element. The airflow directing element may extend longitudinally into the substrate cavity. The airflow directing element may comprise an elongate body extending longitudinally into the matrix cavity. The airflow channel may be defined between an outer surface of the airflow directing element and an inner surface of the aerosol-generating substrate. The width or diameter of the airflow directing element may be smaller than the diameter of the substrate cavity. The aerosol-generating substrate may be referred to as a hollow tubular substrate.

According to the present invention there is provided an aerosol-generating article for generating an inhalable aerosol upon heating. The aerosol-generating article comprises an aerosol-generating substrate. The aerosol-generating substrate is in the form of a hollow tubular section defining a substrate cavity 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 directing element. The airflow directing element extends longitudinally into the matrix cavity. An airflow channel is defined between an outer surface of the airflow directing element and an inner surface of the aerosol-generating substrate. The width or diameter of the airflow directing element may be smaller than the diameter of the substrate cavity. The aerosol-generating substrate may be referred to as a hollow tubular substrate.

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

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

As used herein with reference to 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. Aerosols may include vapors of substances that are typically liquids or solids at room temperature, as well as solid particles or droplets or a combination of solid particles and droplets.

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

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

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 position between an upstream end of the aerosol-generating article and a downstream end of the aerosol-generating article.

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

As used herein with reference to the present disclosure, the term "transverse" is used to describe a direction perpendicular to the longitudinal direction.

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

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

As used herein with reference to the present disclosure, the terms "hollow tubular element" and "hollow tubular matrix element" refer to generally elongated elements defining an inner lumen, cavity, or airflow pathway along a longitudinal axis thereof. In particular, the term "tubular" is used to refer to a tubular element having a substantially cylindrical cross-section and defining at least one gas flow conduit establishing uninterrupted fluid communication between an upstream end of the tubular element and a downstream end of the tubular element. However, it should be understood that alternative geometries (e.g., alternative cross-sectional shapes) of the tubular element may be possible. The hollow tubular element may be a single 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.

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

As used herein with reference to the present disclosure, the term "tobacco particles" describes particles of any plant member of the genus nicotiana. The term "tobacco particles" includes ground or crushed tobacco lamina, ground or crushed tobacco stem, tobacco dust, tobacco fines, and other particulate tobacco by-products formed during the handling, operation, and transportation of tobacco. Preferably, the tobacco particles are substantially entirely derived from tobacco lamina. In contrast, isolated nicotine and nicotine salts are tobacco-derived compounds, but are not considered tobacco particles for purposes of this disclosure.

Providing a matrix element in tubular form may advantageously enable the amount of tobacco material in the aerosol-generating matrix to be optimised so that, when heated, an aerosol may be efficiently generated from the aerosol-generating matrix. The tubular form also removes a central portion of homogenized tobacco material that would likely not be heated as effectively as an outer portion, particularly in an aerosol-generating device comprising an external heating device. In summary, the amount of tobacco material may thus be significantly reduced, and tobacco waste may be reduced, compared to conventional solid rods of homogenized tobacco material. For example, it has been found that the amount of tobacco material used for the hollow tubular matrix element of an aerosol-generating article according to the present disclosure can be reduced by up to 40% as compared to the amount of tobacco material used for a solid rod of matrix in a conventional aerosol-generating article, while maintaining similar aerosol delivery to a consumer.

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

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

By providing an airflow directing element extending longitudinally into an empty substrate cavity defined by the hollow tubular aerosol-generating substrate, an airflow channel or path is defined around the airflow directing element between an outer surface of the airflow directing element and an interior of the aerosol-generating substrate such that air entering the substrate cavity is encouraged to flow closer to the inner surface of the aerosol-generating substrate. The protrusion of the airflow directing element into the cavity effectively provides an airflow path having a reduced cross-section relative to the cross-section of the cavity such that air entering the cavity may be locally accelerated (according to bernoulli's principle) as it flows through such an airflow path. Such local airflow acceleration may enhance extraction of aerosol-forming components from the heated aerosol-generating substrate, which is particularly important for tubular substrates having hollow cores. As a result, such an airflow arrangement may improve aerosol delivery by the hollow tubular substrate and reduce the time required for the substrate to generate an organoleptically acceptable aerosol after being initially heated, while reducing manufacturing costs and potential waste of substrate material that may not contribute to aerosol generation.

Preferably, the hollow tubular matrix element is formed of homogenized tobacco material. Preferably, the hollow tubular matrix element is formed from one or more layers of homogenized tobacco material (e.g. cast leaf).

Preferably, the hollow tubular matrix element is formed from 2 or more plies of homogenized tobacco material, more preferably from 3 or more plies of homogenized tobacco material.

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

Preferably, the multiple overlapping layers of homogenized tobacco material are directly overlying each other such that adjacent layers are in direct contact with each other without an intermediate layer.

The multi-layered arrangement of layers may provide a relatively dense structure with sufficient structural rigidity to provide an aerosol-generating substrate in an aerosol-generating article without any additional support, such as a carrier layer or an internal support member within a longitudinal substrate cavity.

Preferably, the layer of homogenized tobacco material is in the form of a sheet. As used herein with reference to the present disclosure, the term "sheet" describes a layered element having a width and length that is significantly greater than its thickness.

The hollow tubular matrix member can have a length of at least about 5 millimeters, or at least about 7 millimeters, or at least about 10 millimeters.

The hollow tubular matrix member may have a length of up to about 30 millimeters, up to about 25 millimeters, or up to about 20 millimeters.

For example, the hollow tubular matrix element can have a length of between about 5 millimeters and about 30 millimeters, or between about 7 millimeters and about 25 millimeters, or between about 10 millimeters and about 20 millimeters.

Preferably, the hollow tubular matrix member has a length of about 12 millimeters.

As discussed above, the length of the hollow tubular matrix element may advantageously be matched to the longitudinal dimension of a heating element in a corresponding aerosol-generating device to be used for heating an aerosol-generating article. In this way, as much of the aerosol-generating substrate as possible may be heated during use in order to optimise the amount of aerosol that can be generated and reduce the amount of tobacco waste.

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

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

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

Preferably, the outer diameter of the hollow tubular matrix element is smaller than the outer diameter of the aerosol-generating article.

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

Preferably, the hollow tubular matrix element can have an outer diameter of up to about 9 millimeters, or up to about 8 millimeters, or up to about 7.5 millimeters.

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

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

As used herein with reference to the present disclosure, the term "outer diameter" refers to the largest diameter of an aerosol-generating article or component thereof in the transverse direction of the aerosol-generating article at a location along the length of the aerosol-generating article or component thereof. In the case of a range or value of outer diameters of the aerosol-generating articles or components thereof described herein, the outer diameters of the aerosol-generating articles or components thereof may fall within the same range or have the same value along the entire length of the aerosol-generating articles or components thereof. In other words, in the case of a range or value of the outer diameter of an aerosol-generating article or component thereof described herein, the outer diameter of the aerosol-generating article or component thereof may fall within the same range or have the same value at all locations along the length of the aerosol-generating article or component thereof.

The outer diameter of the hollow tubular matrix element does not comprise the width of any other component of the aerosol-generating substrate located outside the hollow tubular matrix element.

The hollow tubular matrix element has a peripheral wall defining a longitudinal cavity or matrix cavity. The wall thickness of the hollow tubular substrate member may be selected based on the desired amount of tobacco material within the hollow tubular substrate. The wall thickness of the hollow tubular matrix member may also be selected such that the hollow tubular matrix member has a sufficiently high stiffness such that it may be self-supporting. The wall thickness of the hollow tubular matrix may also be selected such that the longitudinal cavity has a cross-sectional area that provides a desired Resistance To Draw (RTD) for the hollow tubular matrix element.

The hollow tubular matrix member may have a wall thickness of at least about 4% of an outer diameter of the hollow tubular matrix member, or at least about 5% of an outer diameter of the hollow tubular matrix member, or at least about 6% of an outer diameter of the hollow tubular matrix member.

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

For example, the hollow tubular matrix member may have a wall thickness of between about 4% and about 40% of an outer diameter of the hollow tubular matrix member, or between about 5% and about 30% of an outer diameter of the hollow tubular matrix member, or between about 6% and about 20% of an outer diameter of the hollow tubular matrix member.

Preferably, the hollow tubular matrix member has a wall thickness of about 7% of the outer diameter of the hollow tubular matrix member.

The hollow tubular matrix member may have a wall thickness of at least about 0.3 millimeters, or at least about 0.35 millimeters, or at least about 0.4 millimeters. The hollow tubular matrix member may have a wall thickness of at least about 0.5 millimeters. The hollow tubular matrix member may have a wall thickness of at least about 0.6 millimeters. The hollow tubular matrix member may have a wall thickness of at least about 0.8 millimeters. The hollow tubular matrix member may have a wall thickness of at least about 1 millimeter.

The hollow tubular matrix member may have a wall thickness of up to about 3 millimeters, or up to about 2 millimeters, or up to about 1 millimeter.

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

The hollow tubular matrix member may have a wall thickness of between about 0.5 millimeters and about 2 millimeters. The hollow tubular matrix member may have a wall thickness of between about 1 millimeter and about 2 millimeters.

The hollow tubular matrix member may have a wall thickness of about 0.5 millimeters. The hollow tubular matrix member may have a wall thickness of about 1 millimeter.

As mentioned above, the longitudinal cavity provides an unrestricted flow channel through the hollow tubular matrix member. This means that the hollow tubular matrix element provides a negligible level of resistance to suction (RTD). The term "negligible level RTD" is used to describe RTDs of hollow tubular matrix elements less than 1mm H2O/10 mm in length, preferably less than 0.4mm H2O/10 mm in length, more preferably less than 0.1mm H2O/10 mm in length.

Thus, the longitudinal cavity should be free of any parts that would obstruct the flow of air in the longitudinal direction. Preferably, the longitudinal cavity is substantially hollow. More preferably, the longitudinal cavity is hollow.

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

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

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

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

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

The diameter of the longitudinal cavity corresponds to the inner diameter of the hollow tubular matrix member.

The longitudinal cavity may have a diameter of at least about 1 millimeter, or at least about 2 millimeters, or at least about 3 millimeters.

The longitudinal cavity may have a diameter of up to about 8 millimeters, or up to about 7 millimeters, or up to about 6.5 millimeters.

For example, the longitudinal cavity may have a diameter of between about 1 millimeter and about 8 millimeters, or between about 2 millimeters and about 7 millimeters, or between about 3 millimeters and about 6.5 millimeters.

The longitudinal cavity may have a diameter of about 6 millimeters.

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

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

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

The longitudinal cavity may have a constant diameter along the length of the hollow tubular matrix element. However, the diameter of the longitudinal cavity may vary along the length of the hollow tubular matrix element.

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

The hollow tubular substrate element may comprise one or more susceptor elements positioned in contact with the peripheral wall for inductively heating the homogenized tobacco material during use.

As used herein, the term "susceptor element" refers to an element comprising a material capable of converting electromagnetic energy into heat. When the susceptor element is in an alternating electromagnetic field, the susceptor is heated. Heating of the susceptor element may be a result of at least one of hysteresis losses and eddy currents induced in the susceptor, depending on the electrical and magnetic properties of the susceptor material.

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

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

The aerosol-generating article according to the present disclosure may further comprise an upstream section located upstream of the strip of aerosol-generating substrate. The upstream section is preferably located immediately upstream of the strip of aerosol-generating substrate. The upstream section preferably extends between the upstream end of the aerosol-generating article and the strip of aerosol-generating substrate. The upstream section may comprise one or more upstream elements located upstream of the strip of aerosol-generating substrate. Such one or more upstream elements are described within this disclosure.

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

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

Where the aerosol-generating substrate comprises shredded tobacco (e.g. tobacco cut filler), the upstream section or element thereof may additionally help prevent loss of loose tobacco particles from the upstream end of the article. This may be particularly important, for example, when the shredded tobacco has a relatively low density.

The upstream section or upstream element thereof may also additionally provide a degree of protection for the aerosol-generating substrate during storage, as it covers at least to some extent the upstream end of the aerosol-generating substrate that may otherwise be exposed.

For aerosol-generating articles intended to be inserted into a cavity in an aerosol-generating device such that the aerosol-generating substrate may be heated externally within the cavity, the upstream section or upstream element thereof may advantageously facilitate insertion of the upstream end of the article into the cavity. The inclusion of the upstream element may additionally protect the end of the strip of aerosol-generating substrate during insertion of the article into the cavity, so that the risk of damage to the substrate is minimised.

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

The upstream element may be a porous rod element. The upstream element may be made of a porous material or may include a plurality of openings. This may be achieved, for example, by laser perforation. Preferably, the plurality of openings are evenly distributed over the cross-section of the upstream element. The porosity or permeability of the upstream element may advantageously be designed to provide a particular overall Resistance To Draw (RTD) to the aerosol-generating article without substantially affecting the filtration provided by the other portions of the article.

The upstream element may be formed of an air impermeable material. In such embodiments, the aerosol-generating article may be configured such that air flows into the strip of aerosol-generating substrate through a suitable ventilation means provided in the wrapper.

The upstream element may be formed from a solid cylindrical rod element having a packed cross section. Such rod elements may be referred to as "normal" elements. As mentioned above, the solid rod element may be porous but not have a tubular form and thus do not provide a longitudinal flow channel. The solid rod elements preferably have a substantially uniform cross-section.

The upstream element may be formed from a hollow tubular section defining a longitudinal cavity providing an unrestricted flow channel. Thus, as described above, the upstream element may provide protection to the aerosol-generating substrate while having minimal impact on the overall Resistance To Draw (RTD) and filtration characteristics of the article.

Preferably, the diameter of the longitudinal cavity of the hollow tubular section forming the upstream element is at least 3mm, more preferably at least 3.5 mm, more preferably at least 4 mm, and more preferably at least 4.5 mm. Preferably, the diameter of the longitudinal cavity is maximized so as to minimize the RTD of the upstream section or element thereof.

Preferably, the hollow tubular section has a wall thickness of less than 2mm, more preferably less than 1.5 mm, and more preferably less than 1 mm.

The upstream element of the upstream section may be made of any material suitable for use in aerosol-generating articles. The upstream element may for example be made of the same material as used for one of the other components of the aerosol-generating article, such as the downstream filter segment or the hollow tubular cooling element. Suitable materials for forming the upstream element include filter materials, ceramics, polymeric materials, cellulose acetate, cardboard, zeolites, or aerosol-generating substrates. The upstream element may comprise a rod of cellulose acetate. The upstream element may comprise a hollow acetate tube or a cardboard tube.

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

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

In addition, for articles intended for external heating, the length of the upstream section or upstream element thereof may be used to control the position of the aerosol-generating article within the cavity of the aerosol-generating device. This may advantageously ensure that the position of the aerosol-generating substrate within the cavity may be optimised for heating, and also that the position of any ventilation may be optimised.

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

The upstream section is preferably connected to the strip of aerosol-generating substrate and optionally at least part of the downstream section by means of an outer wrapper as described herein.

The upstream section may comprise a heat source, preferably a combustible heat source, and a heat conducting element. The heat source may define an upstream end of the aerosol-generating article. The heat conducting element may be located between and in direct contact with the heat source and the aerosol-generating substrate. The heat conducting element may conduct heat from the heat source to the aerosol-generating substrate. The thermally conductive element may define, in part, an aerosol-generating substrate. The thermally conductive element may partially define a heat source. The heat source, the heat conducting element and the aerosol-generating substrate may be axially aligned in a sequential abutting manner. The tubular aerosol-generating substrate may comprise at least one perforation to provide 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 aerosol-generating articles are known in the art. Preferably, the combustible heat source is a combustible carbonaceous heat source. As used herein with respect to the present invention, the term "carbon-containing" is used to describe a combustible heat source that includes carbon.

Similar aerosol-generating articles comprising such upstream sections with heat sources and heat conducting elements are further described in WO-up>A-2015/028654, WO-up>A-2015/022321 and WO-up>A-2009/022232.

As mentioned above, the aerosol-generating article comprises an airflow directing element. The airflow directing element extends longitudinally into the longitudinal matrix cavity. A primary airflow path or channel is defined between an outer surface of the airflow directing element and an inner surface of the aerosol-generating substrate. The width or diameter of a portion of the airflow directing element may thus be smaller than the diameter of the substrate cavity.

The airflow directing element may extend into the substrate cavity from any location along the aerosol-generating article. The airflow directing element preferably extends into the substrate cavity from a location upstream of the aerosol-generating substrate. The airflow directing element may extend into the substrate cavity from a location downstream of the aerosol-generating substrate.

As mentioned above, the aerosol-generating article may comprise an upstream section located upstream of the aerosol-generating substrate. The airflow directing element may be coupled to or held by an upstream element adjacent to the upstream end of the aerosol-generating substrate. The airflow directing element may be coupled to or held by a downstream element adjacent to the downstream end of the aerosol-generating substrate. The coupling of the airflow directing element to or holding by the upstream or downstream element allows the airflow directing element to be supported by such upstream or downstream element, rather than by the aerosol-generating substrate itself. This may allow the airflow directing element to extend into the cavity of the aerosol-generating substrate without having to rely on a manufacturing or assembly process that may involve wrapping the aerosol-generating substrate or may otherwise affect the structural integrity of the substrate during the manufacturing or assembly process. This therefore allows the airflow directing element having a maximum width or diameter smaller than the inner diameter of the aerosol-generating substrate to extend into the cavity of the aerosol-generating substrate without any internal contact of the airflow directing element with the aerosol-generating substrate. In other words, the airflow directing element may be effectively cantilevered and extend into the cavity of the substrate without the need to wrap or define the support formed by the aerosol-generating substrate around the airflow directing element or a portion thereof.

The aerosol-generating article may comprise a base support element from which the airflow directing element may extend. The upstream section may comprise 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 approximately equal to the outer diameter of the aerosol-generating substrate.

The base support element may be located downstream of the aerosol-generating substrate such that the airflow directing element may extend from a location 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.

The base support element may be located within an upstream element located upstream of the aerosol-generating substrate. The base support element may be located within a downstream element located downstream of the aerosol-generating substrate. The base support element may be held or embedded within an upstream element located upstream of the aerosol-generating substrate. The base support element may be held or embedded within a downstream element located downstream of the aerosol-generating substrate. For example, the downstream or upstream element may comprise a hollow tubular element defining a longitudinal cavity, and the base support element may be sized such that it remains within such longitudinal cavity.

The base support element may have a disc or plate shape, preferably a cylindrical shape. Preferably, the base support element is porous or comprises at least one aperture. This enables fluid communication to be established between the exterior of the aerosol-generating article and the interior of the aerosol-generating substrate by the base support element.

The airflow directing element preferably comprises an elongate body extending longitudinally into the matrix cavity. The airflow directing element preferably comprises an elongate body extending from an upstream end of the airflow directing element to a downstream end of the airflow directing element. The airflow directing element preferably comprises an elongate body extending from a fixed end of the airflow directing element to a free end of the airflow directing element.

In case the base support element is located upstream of the aerosol-generating substrate, the upstream end of the airflow directing element may be coupled to the base support element. In case the base support element is located downstream of the aerosol-generating substrate, the downstream end of the airflow directing element may be coupled to the base support element. The central longitudinal axis of the airflow directing element may be aligned with the central longitudinal axis of the base support element. The airflow directing element preferably comprises an elongate body extending from a fixed end of the airflow directing element to a free end of the airflow directing element. The end of the airflow directing element coupled to the base support element may define a fixed end of the airflow directing element, while the opposite end may be a free end of the airflow directing element.

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

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

The elongate body of the airflow directing element may be strip-shaped or conical. The elongate body of the airflow directing element preferably comprises a hollow body or tube defining a longitudinal cavity. The elongate body of the airflow directing element preferably comprises a hollow cylindrical tube defining a longitudinal cavity.

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

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

The downstream end of the hollow body may be porous or may be provided with one or more perforations, apertures, inlets or outlets such that fluid communication is established between the interior of the hollow body and the matrix cavity and a secondary airflow path into the matrix 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 substrate cavity and a secondary airflow path within the airflow directing element is defined. If the airflow directing element spans the entire length of the substrate cavity, the secondary airflow path may direct air directly to a downstream section of the article. If the airflow directing element extends along less than 100% of the length of the substrate cavity, the secondary airflow path may direct air into the substrate cavity of the article.

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

Where the airflow directing element comprises a hollow body, perforations or holes may be provided that extend through the peripheral wall of the hollow body defining the longitudinal cavity. The peripheral wall of the hollow body may be porous. Such one or more perimeter perforations may track a particular path along or around the hollow body of the airflow directing element. Such one or more perimeter perforations may track a linear, spiral, curved, or wavy path along or around the hollow body of the airflow directing element. This advantageously allows fluid communication to be established between the interior of the hollow body and the matrix cavity such that one or more secondary gas flow paths into the matrix cavity are defined. Air may flow through the base support element into the hollow body or tube of the airflow directing element and exit through the peripheral wall of the hollow body into the substrate cavity. Air passing through the hollow body may also exit into the matrix cavity via an opening at the downstream end of the hollow body. Such secondary air flow may provide dilution and cooling functions for the primary air flow travelling downstream between the air flow guiding element and the inner surface of the aerosol-generating element.

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

The airflow directing element may be textured. The airflow directing element may have a non-uniform outer surface or a convex outer surface. The airflow directing element may comprise a raised element on an outer surface thereof. The airflow directing element may comprise one or more grooves, recesses, bumps, protrusions or protuberances provided on its outer surface. By having a textured or non-uniform outer surface, the airflow directing element can interfere with the air flowing therearound so as to create local turbulence, which can enhance mixing of the air with the released aerosol-forming component.

The airflow directing element may comprise a plurality or series of aligned segments forming an elongate body. Each segment may have any shape. The segments may each be pyramid-shaped, bar-shaped, cylindrical, conical, circular, spherical or hemispherical. For example, the airflow directing element may comprise a plurality of aligned conical sections to form an elongate body.

The airflow directing element may comprise a core elongate portion (according to the elongate body described above) and at least one extension positioned along the core portion. The at least one extension may comprise a bump, protrusion or protuberance provided on the outer surface of the core portion. At least one extension may be formed on the outer surface of the core portion. The at least one extension may define a raised surface on the airflow directing element, preferably on a core portion thereof. The at least one extension may extend outwardly (in other words away from the central axis of the core portion) from the core portion. The at least one extension may extend radially from the core portion. The at least one extension may extend longitudinally along the core portion. The at least one extension may extend fully or partially circumferentially around the core portion.

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

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

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

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

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

Advantageously, the amount of turbulence and turbulence created in the air flowing around the airflow directing element may be tailored to the size of the extension relative to the airflow directing element, the location of the or each extension along the airflow directing element, and the distance between sequential or adjacent extensions.

The extension may be provided at the upstream end of the airflow directing element or core portion thereof. The extension may be provided at the downstream end of the airflow directing element or the core portion thereof.

Sequential or adjacent extensions may be spaced apart from one another to define a gap therebetween. The extension portions may be uniformly spaced apart from each other. Providing gaps between sequential or adjacent extensions defines sections of the primary air flow channel in which the cross-sectional area increases, primarily when the cross-section of the extensions is uniform along its length (e.g., a cylinder or ring), thereby allowing the air to locally decelerate after flowing through the upstream extension or before flowing through the downstream extension. The outer surface of the core portion may be exposed through such a gap.

The base support element and the airflow guiding element may be manufactured separately and subsequently coupled to each other prior to assembling the aerosol-generating article. The base support element and the airflow guiding element may be integrally formed with each other, for example by extrusion or by injection moulding. Similarly, the core portion and any extension of the airflow directing element may be manufactured separately and subsequently coupled to each other prior to assembly of the aerosol-generating article. Any extensions of the core portion and the air flow guiding element may be integrally formed with each other, for example by extrusion or by injection moulding. The extension may be manufactured separately from the core portion and may be subsequently assembled to the core portion. For example, the extension portion may be an annular or cylindrical element mounted to and coupled to the core portion. For example, such annular or cylindrical elements may be slid onto the core portion and coupled thereto by means of an adhesive or interference fit.

The material of the base support element and the material of the air flow guiding element may be the same. The airflow directing element, the base support element, or both may be formed of a non-metallic material. The airflow directing element, the base support element, or both may not include a metallic material. The airflow directing element, the base support element, or both may be formed from cardboard. The airflow directing element, the base support element, or both may be formed from a paper-based material. The airflow directing element, the base support element, or both may be formed of paper. The airflow directing element, the base support element, or both may be formed from a polymeric material. The airflow directing element, the base support element, or both may be formed of a plastic material. The airflow directing element, the base support element, or both may be formed of a bio-plastic material. The airflow directing element, the base support element, or both may be formed from cellulose acetate. The materials mentioned in this disclosure may provide suitable resistance to deformation or compression while providing a base support element and an airflow directing element that may be cost effectively manufactured.

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

The airflow directing element may comprise an outer layer or coating disposed at least partially on the outer surface, preferably on the outer surface of the airflow directing element body. The outer layer or coating may include one or more of an aerosol-former, a flavoring agent, and an additional aerosol-generating substrate. Such aerosol-forming agents, flavors and additional aerosol-generating substrates of the outer layer or coating may be respectively compatible with aerosol-forming agents, flavors and aerosol-generating substrates as described in the present disclosure.

The length of the airflow directing element preferably corresponds to the amount by which the airflow directing element extends into the substrate cavity.

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

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

The length of the airflow directing element may be between about 1mm and about 30mm, between about 3mm and about 30mm, between about 5mm and about 30mm, between about 6mm and about 30mm, between about 8mm and about 30mm, or preferably between about 9mm and about 30 mm. The length of the airflow directing element may be between about 1mm and about 25mm, between about 3mm and about 25mm, between about 5mm and about 25mm, between about 6mm and about 25mm, between about 8mm and about 25mm, or preferably between about 9mm and about 25 mm. The length of the airflow directing element may be between about 1mm and about 20mm, between about 3mm and about 20mm, between about 5mm and about 20mm, between about 6mm and about 20mm, between about 8mm and about 20mm, or preferably between about 9mm and about 20 mm. The length of the airflow directing element may be between about 1mm and about 15mm, between about 3mm and about 15mm, between about 5mm and about 15mm, between about 6mm and about 15mm, between about 8mm and about 15mm, or preferably between about 9mm and about 15 mm. The length of the airflow directing element may be between about 1mm and about 12mm, between about 3mm and about 12mm, between about 5mm and about 12mm, between about 6mm and about 12mm, between about 8mm and about 12mm, or preferably between about 9mm and about 12 mm. The length of the airflow directing element may be between about 1mm and about 10mm, between about 3mm and about 10mm, between about 5mm and about 10mm, between about 6mm and about 10mm, between about 8mm and about 10mm, or preferably between about 9mm and about 10 mm.

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

The length of the airflow directing element defines the length of a restricted airflow path or channel defined between the outer surface of the airflow directing element and the inner surface of the aerosol-generating substrate. It will be appreciated that a balance may be struck between providing a relatively long airflow directing element so as to define a relatively long restricted airflow path and providing the manufacturing costs of such a long airflow directing element. Desirably, the length of the airflow directing element may be at least about 50%, preferably at least about 60% of the length of the aerosol-generating substrate or substrate cavity.

Preferably, the central or longitudinal axis of the airflow directing element is aligned with the central or longitudinal axis of the aerosol-generating substrate. Preferably, the airflow directing element is axially symmetrical. This may ensure that the restricted airflow channel defined around the airflow directing element and between the airflow directing element and the inner surface of the aerosol-generating substrate is axially symmetrical.

The air flow guiding element has a maximum outer diameter. The one or more raised surfaces or extensions of the airflow directing element may define a maximum outer diameter or width of the airflow directing element. Thus, the diameter or width of the airflow directing element may vary or oscillate along the length of the airflow directing element.

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

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

The maximum outer diameter or width of the airflow directing element may be between about 1mm and about 8mm, between about 2mm and about 8mm, between about 2.5mm and about 8mm, or preferably between about 3mm and about 8 mm. The maximum outer diameter or width of the airflow directing element may be between about 1mm and about 7.5mm, between about 2mm and about 7.5mm, between about 2.5mm and about 7.5mm, or preferably between about 3mm and about 7.5 mm. The maximum outer diameter or width of the airflow directing element may be between about 1mm and about 7mm, between about 2mm and about 7mm, between about 2.5mm and about 7mm, or preferably between about 3mm and about 7 mm. The maximum outer diameter or width of the airflow directing element may be between about 1mm and about 6mm, between about 2mm and about 6mm, between about 2.5mm and about 6mm, or preferably between about 3mm and about 6 mm.

The maximum outer diameter or width of the airflow directing element may be at least about 25% 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 directing element may be at least about 40% 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 directing element may be at least about 50% 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 directing element may be at least about 60% 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 directing element may be at least about 75% of the inner diameter of the aerosol-generating substrate or the diameter of the substrate cavity.

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

The diameter or any diameter of the portion of the airflow directing element upstream of the portion of the airflow directing element whose diameter corresponds to the maximum outer diameter or width of the airflow directing element is preferably less than (or not more than) the maximum outer diameter or width of the airflow directing element.

The airflow directing element may have a minimum outer diameter. For airflow directing elements having a uniform outer diameter or width, the diameter or width of the airflow directing element may correspond to a maximum outer diameter or width or a minimum outer diameter or width. The core portion of the airflow directing element may define a minimum outer diameter or width of the airflow directing element.

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

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

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

The minimum outer diameter or width of the airflow directing element may be at least about 10% 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 directing element may be at least about 20% 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 directing element may be at least about 25% 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 directing element may be at least about 40% 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 directing element may be at least about 50% 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 directing element may be at least about 60% 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 directing element may be about 100% of the inner diameter of the aerosol-generating substrate or the diameter of the substrate cavity. Thus, a portion of the airflow directing element may be in contact with the aerosol-generating substrate. A portion of the extended or raised portion of the airflow directing element may be in contact with the aerosol-generating substrate. Sizing the airflow directing element to contact the aerosol-generating substrate may facilitate centering the airflow directing element with the substrate cavity and may help retain the airflow directing element within the substrate cavity.

The airflow directing element may extend along a central axis of the substrate cavity. A longitudinal gap or space may be defined between the outer surface of the airflow directing element and the inner circumferential surface of the aerosol-generating substrate. The outer surface of the airflow directing element or a 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 directing element and the inner surface of the aerosol-generating substrate. Preferably, such a defined airflow channel may be referred to as a primary airflow channel or a restricted airflow channel.

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

The distance between the outer surface of the airflow directing element and the inner surface of the aerosol-generating substrate may define the height or thickness of the primary airflow channel or the restricted airflow channel. The height or thickness of the airflow channels may vary longitudinally or circumferentially or both longitudinally and circumferentially, subject to the local diameter or width of the airflow directing element at specific longitudinal and circumferential locations along the elongate body of the airflow directing element.

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

The minimum thickness of the airflow channel may be at least about 0mm. In other words, a portion of the airflow directing element may be in contact with the aerosol-generating substrate such that there is no distance or gap between such portion of the airflow directing element and the aerosol-generating substrate. The minimum thickness of the airflow channel may be at least about 0.25mm. The minimum thickness of the airflow channel may be at least about 0.5mm. The minimum thickness of the airflow channel may be at least about 1.5mm. The airflow directing element may not contact the inner surface of the aerosol-generating substrate. Along its entire length, the airflow directing element may not contact the inner surface of the aerosol-generating substrate. In other words, no part of the outer surface of the airflow directing element contacts the inner surface of the aerosol-generating substrate. This enables thicker and less obstructed airflow channels to be defined, enabling more airflow to travel between the inner surface of the aerosol-generating substrate and the airflow directing element.

The maximum thickness of the airflow channel may be up to about 6mm. The maximum thickness of the airflow channel may be up to about 5mm. The maximum thickness of the airflow channel may be up to about 3mm. The maximum thickness of the airflow channel may be up to about 2.5mm.

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

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

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

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

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

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

In the context of the present disclosure, the hollow tubular element of the downstream section provides an unrestricted flow channel through the airflow passage. This means that the hollow tubular element provides a negligible level of resistance to suction (RTD) as defined above. Thus, the air flow path should be free of any components that obstruct the flow of air in the longitudinal direction. Preferably, the airflow path is substantially empty.

The hollow tubular element of the downstream section provides a cavity downstream of the aerosol-generating substrate, which may enhance cooling and nucleation of aerosol particles generated by the aerosol-generating substrate. The hollow tubular element of the downstream section may thus be used as an aerosol-cooling element.

The hollow tubular member may be at least about 12mm in length. The hollow tubular member may be at least about 15mm in length. The hollow tubular member may be at least about 20mm in length.

The hollow tubular element of the downstream section may have a length of less than or equal to about 50mm. The hollow tubular member may have a length of less than or equal to about 45mm. The hollow tubular member may have a length of less than or equal to about 40mm.

For example, the hollow tubular element of the downstream section may have a length between about 12mm and 50 mm. The hollow tubular member may be between about 15mm and 45mm in length. The hollow tubular element may have a length of between about 20mm and 40 mm. The hollow tubular member may be about 30mm in length.

A relatively long hollow tubular element is provided within the downstream section of the aerosol-generating article and defines a relatively long lumen. Providing a relatively long cavity may maximize the nucleation benefits described above, thereby improving aerosol formation and cooling.

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

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

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

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

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

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

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

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

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

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

The wall thickness of the hollow tubular element of the downstream section may be less than or equal to about 2 millimeters, preferably less than or equal to about 1.5 millimeters, and even more preferably less than or equal to about 1.25mm. The hollow tubular member of the downstream section may have a wall thickness of less than or equal to about 1 millimeter. The hollow tubular member of the downstream section may have a wall thickness of less than or equal to about 500 microns.

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

Keeping the wall thickness of the hollow tubular section of the downstream section relatively low ensures that the overall internal volume of the hollow tubular element (which is made available for the aerosol to begin the nucleation process once the aerosol components leave the aerosol-generating substrate) and the cross-sectional surface area of the cavity of the hollow tubular element is effectively maximized, while ensuring that the hollow tubular element has the necessary structural strength to prevent collapse of the aerosol-generating article and to provide some support for the strip of 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 lumen of the hollow tubular element is understood to be associated with a reduced velocity of the aerosol-generating stream travelling along the aerosol-generating article, which reduced velocity is also expected to facilitate aerosol nucleation. Furthermore, it appears that by utilizing a hollow tubular element having a relatively low thickness, ventilation air may be substantially prevented from diffusing before it is contacted and mixed with the aerosol flow, which is also understood to further facilitate nucleation. Indeed, by providing a more controllable localized cooling of the volatile material flow, it is possible to enhance the effect of cooling on the formation of new aerosol particles.

Preferably, the outer diameter of the hollow tubular element of the downstream section is approximately equal to the outer diameter of the aerosol-generating substrate and the outer diameter of the aerosol-generating article. The hollow tubular element of the downstream section preferably has an outer diameter which is larger than the outer diameter of the hollow tubular matrix element of the aerosol-generating substrate.

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

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.

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

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

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

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

It is particularly preferred that the inner diameter of the hollow tubular matrix member is substantially equal to the inner diameter of the hollow tubular member of the downstream section.

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

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

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

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 paper layers. The paper may have a basis weight of at least about 50 grams per square meter, at least about 60 grams per square meter, at least about 70 grams per square meter, or at least about 90 grams per square meter.

The hollow tubular element of the downstream section may comprise a polymeric material. For example, the hollow tubular element may comprise a polymer membrane. The polymer film may comprise a cellulosic film. The hollow tubular segments may comprise Low Density Polyethylene (LDPE) or Polyhydroxyalkanoate (PHA) fibers. The hollow tubular member may comprise cellulose acetate tow.

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

The hollow tubular element may be at an upstream end of the downstream section. The hollow tubular element may abut the downstream end of the aerosol-generating substrate. The hollow tubular element may abut a downstream end of the hollow tubular matrix element.

An aerosol-generating article according to the disclosure may comprise a ventilation zone at a location along the downstream section. In more detail, where the downstream section comprises a hollow tubular element, the ventilation zone may be provided at a location along the hollow tubular element.

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

The ventilation zone may generally comprise 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 any wrapper defining the hollow tubular element. Preferably, the ventilation zone comprises at least one row of circumferential perforations. The ventilation zone may include two rows of circumferential perforations. For example, perforations may be formed on the production line during manufacture of the aerosol-generating article. Preferably, each row of circumferential perforations comprises 8 to 30 perforations.

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

Providing a mouthpiece element at the downstream end of an aerosol-generating article according to the present disclosure may provide an attractive appearance and mouthfeel to the consumer.

The mouthpiece element may be a mouthpiece filter element. The mouthpiece element may comprise at least one mouthpiece filter segment formed from fibrous filter material. The parameters or characteristics described in relation to the mouthpiece element as a whole are equally applicable to the mouthpiece filter segment of the mouthpiece element.

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

The mouthpiece element may be constituted by a single mouthpiece filter segment. The mouthpiece element may comprise two or more mouthpiece filter segments axially aligned with each other in abutting end-to-end relationship.

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

The mouthpiece element may optionally include a flavour, which may be provided in any suitable form. For example, the mouthpiece element may comprise one or more capsules, beads or particles of flavour, or one or more filaments or threads carrying flavour.

Preferably, the mouthpiece element or its mouthpiece filter segment has a low particulate filtration efficiency.

Preferably, the mouthpiece element is defined by a rod wrapper. Preferably, the mouthpiece element is non-ventilated such that air does not enter the aerosol-generating article along the mouthpiece element.

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

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

The Resistance To Draw (RTD) of a component or aerosol-generating article is measured according to ISO6565-2015 unless otherwise specified. RTD refers to the pressure required to force air through the entire length of the component. The term "pressure drop" or "resistance to draw" of a component or article may also refer to "resistance to draw".

The downstream segment can have a Resistance To Draw (RTD) of at least about 0mm h2o. The RTD of the downstream segment may be at least about 3mm h2o. The RTD of the downstream segment may be at least about 6mm h2o.

The RTD of the downstream segment may be no greater than about 12mm h2o. The RTD of the downstream segment may be no greater than about 11mm h2o. The RTD of the downstream segment may be no greater than about 10mm h2o.

The suction resistance of the downstream section may be greater than or equal to about 0mm h2o and less than about 12mm h2o. Preferably, the suction resistance of the downstream section may be greater than or equal to about 3mm h2o and less than about 12mm h2o. The suction resistance of the downstream section may be greater than or equal to about 0mm h2o and less than about 11mm h2o. Even more preferably, the suction resistance of the downstream section may be greater than or equal to about 3mm h2o and less than about 11mm h2o. Even more preferably, the suction resistance of the downstream section may be greater than or equal to about 6mm h2o and less than about 10mm h2o. Preferably, the suction resistance of the downstream section may be about 8mm h2o.

The Resistance To Draw (RTD) characteristics of the downstream segment may be attributed entirely or primarily to the RTD characteristics of the mouthpiece element of the downstream segment. In other words, the RTD of the mouthpiece element of the downstream segment may fully define the RTD of the downstream segment.

The mouthpiece element may have a Resistance To Draw (RTD) of at least about 0mm h2o. The RTD of the mouthpiece element may be at least about 3mm h2o. The RTD of the mouthpiece element may be at least about 6mm h2o.

The RTD of the mouthpiece element may be no greater than about 12mm h2o. The RTD of the mouthpiece element may be no greater than about 11mm h2o. The RTD of the mouthpiece element may be no greater than about 10mm h2o.

The mouthpiece element may have a resistance to draw greater than or equal to about 0mm h2o and less than about 12mm h2o. Preferably, the mouthpiece element may have a resistance to draw greater than or equal to about 3mm h2o and less than about 12mm h2o. The mouthpiece element may have a resistance to draw greater than or equal to about 0mm h2o and less than about 11mm h2o. Even more preferably, the mouthpiece element may have a resistance to draw greater than or equal to about 3mm h2o and less than about 11mm h2o. Even more preferably, the mouthpiece element may have a resistance to draw greater than or equal to about 6mm h2o and less than about 10mm h2o. Preferably, the mouthpiece element may have a resistance to draw of about 8mm h2o.

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

The mouthpiece element may be formed from a polylactic acid based material. The mouthpiece element may be formed from a bio-plastics material, preferably a starch-based bio-plastics material. The mouthpiece element may be made by injection moulding or by extrusion. Bio-plastic based materials are advantageous because they can provide a mouthpiece element structure that is simple and inexpensive to manufacture, has a specific and complex cross-sectional profile, and that can include a plurality of relatively large air flow channels extending through the mouthpiece element material, which provides suitable RTD characteristics.

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

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

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

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

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

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

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

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

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

Where 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 may be at least about 1.5. In other words, the length of the hollow tubular element may be at least about 150% of the length of the mouthpiece element. The ratio of the length of the hollow tubular element to the length of the mouthpiece element may be at least about 5. The ratio of the length of the hollow tubular element to the length of the mouthpiece element may be at least about 7.5.

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

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

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

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

For example, the downstream section may have an overall length of between about 20 millimeters and about 50 millimeters, more preferably between about 25 millimeters and about 45 millimeters, more preferably between about 30 millimeters and about 40 millimeters.

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

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

Preferably, the overall length of the aerosol-generating article according to the invention is at least about 35 mm. More preferably, the aerosol-generating article according to the invention has an overall length of at least about 40 mm. Even more preferably, the overall length of the aerosol-generating article according to the invention is at least about 45 mm. Even more preferably, the aerosol-generating article according to the invention has an overall length of at least about 50 mm.

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

For example, the overall length of the aerosol-generating article may be between about 35 millimeters and about 110 millimeters, or between about 40 millimeters and about 100 millimeters, or between about 45 millimeters and about 75 millimeters, or between about 50 millimeters and about 70 millimeters.

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

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

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

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

One or more of the components of the aerosol-generating article may be defined solely by its own wrapper.

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

Preferably, the components of the aerosol-generating article according to the present disclosure are made of biodegradable materials.

Preferably, an aerosol-generating article according to the present disclosure as described herein is suitable for use in an electrically operated aerosol-generating system, wherein the aerosol-generating substrate of the heated aerosol-generating article is heated by an 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 thermally proximate to the aerosol-generating substrate. The susceptor may be in direct contact with the aerosol-generating substrate and heat is transferred from the susceptor to the aerosol-generating substrate mainly by conduction. Examples of electrically operated aerosol-generating systems with induction heating means and aerosol-generating articles with susceptors are described in WO-A1-95/27411 and WO-A1-2015/177255.

The present disclosure relates to an aerosol-generating system comprising an aerosol-generating device having a distal end and a mouth 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 an aerosol-generating article at the mouth 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.

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

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

The expression "received within" may refer to the fact that a component or element is received entirely or partially within another component or element. For example, the expression "the aerosol-generating article is received within the device cavity" means that the aerosol-generating article is received completely or partially within the device cavity of the aerosol-generating article. The aerosol-generating article may abut a distal end of the device cavity when the aerosol-generating article is received within the device cavity. When the aerosol-generating article is received within the device cavity, the aerosol-generating article may be substantially proximal to the distal end of the device cavity. The distal end of the device lumen may be defined by an end wall.

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

The length of the device lumen may be between about 15 millimeters and about 80 millimeters. Preferably, the length of the device lumen is between about 20 mm and about 70 mm. More preferably, the length of the device lumen is between about 25mm and about 60 mm. More preferably, the length of the device is between about 25mm and about 50 mm.

The length of the device lumen may be between about 25 millimeters and about 29 millimeters. Preferably, the length of the device lumen is between about 25 mm and about 29 mm. More preferably, the length of the device lumen is between about 26 millimeters and about 29 millimeters. Even more preferably, the length of the device lumen is about 27 millimeters or about 28 millimeters.

The diameter of the device lumen may be between about 4 mm and about 10 mm. The diameter of the device lumen may be between about 5mm and about 9 mm. The diameter of the device lumen may be between about 6 mm and about 8 mm. The diameter of the device lumen may be between about 6 millimeters and about 7.5 millimeters.

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

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

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

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

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

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

The heating chamber or device cavity may be dimensioned such that a longitudinal gap is provided between the aerosol-generating article received therein and a peripheral wall defining the device cavity. Such a longitudinal gap may partially or fully define an aerosol-generating article received within the device. Such a longitudinal gap or space may define an air intake passage extending from an open mouth end of the device lumen to a closed distal end of the device lumen. Further, the device housing may be configured such that air may 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 the cavity may be such that fluid communication is established between the inlet channel of the device, preferably at the distal end of the device cavity, and the upstream end of the received aerosol-generating article. Thus, upon drawing in the inserted aerosol-generating article, air may enter the aerosol-generating device through the air inlet channel and flow to the distal end of the device cavity and into the upstream end of the received article.

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

The heating element of such an aerosol-generating device may be of any suitable form to conduct heat. The heating of the aerosol-generating substrate may be effected internally, externally or both internally and externally. 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. The heating element may preferably partially or completely surround the substrate and externally heat the substrate circumferentially from the outside.

Preferably, the heater may heat the aerosol-generating article externally when the aerosol-generating article is received within the aerosol-generating device. Such an external heater may define the aerosol-generating article when the aerosol-generating article is inserted into or received within the aerosol-generating device. Preferably, the length of the heater substantially corresponds to the length of an aerosol-generating substrate of an aerosol-generating article the aerosol-generating device is configured to receive.

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

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

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

The heater may comprise an induction heating element. The induction heating element may be a susceptor element. As used herein, the term "susceptor element" refers to an element comprising a material capable of converting electromagnetic energy into heat. When the susceptor element is in an alternating electromagnetic field, the susceptor is heated. Heating of the susceptor element may be a result of at least one of hysteresis losses and eddy currents induced in the susceptor, depending on the electrical and magnetic properties of the susceptor material.

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

The susceptor element may be positioned in contact with the aerosol-generating substrate. The susceptor element may be located in an aerosol-generating device. The susceptor element may be located in or around the periphery of the device cavity. The aerosol-generating device may comprise 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 may define an aerosol-generating article when the aerosol-generating article is received within the heating chamber.

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

The susceptor element may comprise a non-metallic core on which a metal layer is provided. For example, the susceptor element may comprise a metal track formed on an outer surface of a ceramic core or substrate.

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

During use, the heater is controllable to operate within a defined operating temperature range below a maximum operating temperature. An operating temperature range between about 150 degrees celsius and about 300 degrees celsius in the heating chamber (or device cavity) is preferred. The operating temperature range of the heater may be between about 150 degrees celsius and about 250 degrees celsius.

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

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

The aerosol-generating device may comprise a power supply. The power source may be a DC power source. In some embodiments, the power source is a battery. The power source may be a nickel metal hydride battery, a nickel cadmium battery or a lithium-based battery, such as a lithium cobalt battery, a lithium iron phosphate battery or a lithium polymer battery. However, in some embodiments, the power source may be another form of charge storage device, such as a capacitor. The power supply may need to be recharged and may have a capacity that allows for storing sufficient energy for one or more user operations (e.g., one or more aerosol-generating experiences). For example, the power source may have sufficient capacity to allow continuous heating of the aerosol-generating substrate for a period of about six minutes, corresponding to typical times spent drawing a conventional cigarette, or for times that are multiples of six minutes. In another example, the power source may have sufficient capacity to allow a predetermined number of puffs or discrete activations of the heater.

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

EX1. An aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article comprising an aerosol-generating substrate, wherein the aerosol-generating substrate is in the form of a hollow tubular section defining a substrate cavity extending from an upstream end of the aerosol-generating substrate to a downstream end of the aerosol-generating substrate.

EX2. The aerosol-generating article of example EX1, further comprising an airflow directing element, wherein the airflow directing element extends longitudinally into the matrix cavity.

EX3. The aerosol-generating article according to example EX2, wherein an airflow channel is defined between an outer surface of the airflow directing element and an inner surface of the aerosol-generating substrate.

EX4. The aerosol-generating article according to example EX2 or EX3, wherein the width or diameter of the airflow directing element is less than the diameter of the matrix cavity.

EX5 the aerosol-generating article according to any one of examples EX2 to EX4, further comprising an upstream section upstream of the aerosol-generating substrate, wherein the upstream section comprises an upstream element adjacent to an upstream end of the aerosol-generating substrate, wherein the airflow directing element is coupled to or held by the upstream element.

EX6 the aerosol-generating article of any of examples EX2 to EX5, wherein the width or diameter of the airflow directing element varies along its length.

EX7 the aerosol-generating article according to any one of examples EX2 to EX6, wherein a portion of the airflow directing element contacts a portion of the aerosol-generating substrate.

EX8 the aerosol-generating article of any one of examples EX2 to EX7, wherein a width or diameter of a portion of the airflow directing element substantially corresponds to a diameter of the matrix cavity.

EX9 the aerosol-generating article of any of examples EX2 to EX8, wherein the airflow directing element extends along at least 25% of the length of the matrix cavity.

EX10 the aerosol-generating article according to any one of examples EX2 to EX9, wherein the airflow directing element extends along at least 50% of the length of the matrix cavity.

EX11 the aerosol-generating article according to any one of examples EX2 to EX10, wherein the airflow directing element extends along at least 60% of the length of the matrix cavity.

EX12 the aerosol-generating article according to any one of examples EX2 to EX11, wherein the airflow directing element comprises a central core portion and an extension portion positioned along the core portion, wherein the extension portion extends outwardly from the core portion.

EX13. The aerosol-generating article of example EX12, wherein the extension is substantially shaped in the form of a hemisphere, sphere, cylinder, cone or ring.

EX14. Aerosol-generating article according to example EX12 or EX13, wherein the core portion is substantially shaped in the form of a rod, tube or cone.

EX15 the aerosol-generating article according to any one of examples EX12 to EX14, wherein the airflow directing element comprises at least two extensions positioned along the core portion.

EX16 the aerosol-generating article according to any one of examples EX12 to EX14, wherein the airflow directing element comprises at least two extensions each positioned at a different location along the core portion.

EX17 the aerosol-generating article according to any one of examples EX2 to EX16, wherein the airflow directing element comprises a hollow tube.

The aerosol-generating article of any of examples EX2 to EX17, further comprising a base support element, and wherein the airflow directing element extends from the base support element.

EX19 the aerosol-generating article of example EX18, wherein the base support element is located upstream of the aerosol-generating substrate.

EX20. An aerosol-generating article according to example EX18 or EX19, wherein the base support element is located within an upstream section or upstream element of the aerosol-generating article.

EX21. An aerosol-generating article according to example EX18 or EX19, wherein the base support element is held within an upstream element of the aerosol-generating article.

An aerosol-generating article according to any of examples EX18 to EX21, wherein the base support element is porous or comprises at least one aperture such that fluid communication is established between the exterior of the aerosol-generating article and the interior of the aerosol-generating substrate.

EX23 the aerosol-generating article according to any of examples EX2 to EX22, wherein the outer longitudinal surface of the airflow directing element and the inner longitudinal surface of the aerosol-generating substrate define the airflow channel.

EX24. The aerosol-generating article according to example EX5, wherein the upstream element comprises a solid rod segment.

EX25. The aerosol-generating article of example EX5, wherein the upstream element comprises a hollow tubular section.

EX26 the aerosol-generating article of any of examples EX2 to EX25, wherein the airflow directing element comprises an airflow inlet at a first location and an airflow outlet at a second location downstream of the first location such that an airflow path is defined within and along the airflow directing element.

EX27 the aerosol-generating article according to any of examples EX2 to EX26, further comprising a downstream section downstream of the aerosol-generating substrate, the downstream section comprising one or more of a mouthpiece element and a hollow tubular element.

EX28. The aerosol-generating article of example EX27, wherein the mouthpiece element comprises at least one mouthpiece filter segment formed of fibrous filter material.

EX29 an aerosol-generating article according to any preceding example, wherein the aerosol-generating substrate has a length of between 5mm and 30 mm.

EX30. An aerosol-generating article according to any preceding example, wherein the aerosol-generating substrate has a length of between 5mm and 16 mm.

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

An aerosol-generating article according to any preceding example, wherein the aerosol-generating substrate has a wall thickness of at least 200 microns.

EX33. An aerosol-generating article according to any preceding example, wherein the aerosol-generating substrate comprises homogenized tobacco material.

EX34. An aerosol-generating article according to any preceding example, wherein the aerosol-generating substrate is formed from a plurality of overlapping sheets of homogenized tobacco material.

EX35 an aerosol-generating article according to any preceding example, wherein the aerosol-generating substrate comprises one or more aerosol-forming agents, and wherein the content of aerosol-forming agents in the aerosol-generating substrate is between at least 10 and 20 wt% on a dry weight basis.

EX36 the aerosol-generating article according to any one of examples EX2 to EX35, wherein a portion of the airflow directing element is coated with one or more of a further aerosol-generating substrate, a flavouring agent, and an aerosol-former.

EX37 the aerosol-generating article of example EX35 or EX36, wherein the aerosol-former comprises one or more of glycerol and propylene glycol.

An aerosol-generating article according to any of examples EX2 to EX37, wherein the maximum width or diameter of the portion of the airflow directing element extending into the matrix cavity is at least about 25% of the diameter of the matrix cavity.

EX39 the aerosol-generating article according to any one of examples EX2 to EX37, wherein the maximum width or diameter of the portion of the airflow directing element extending into the matrix cavity is at least about 50% of the diameter of the matrix cavity.

EX40 the aerosol-generating article according to any one of examples EX2 to EX37, wherein the maximum width or diameter of the portion of the airflow directing element extending into the matrix cavity is at least about 75% of the diameter of the matrix cavity.

EX41 the aerosol-generating article according to any one of examples EX2 to EX40, wherein the outer surface of the airflow directing element is textured.

EX42. An aerosol-generating system comprising an aerosol-generating article according to any of the preceding examples and an aerosol-generating device comprising a heating chamber for receiving the aerosol-generating article and heating elements arranged at or around the periphery of the heating chamber.

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

fig. 1 shows a schematic side cross-sectional view of an aerosol-generating article according to an embodiment of the invention;

Fig. 2 shows a schematic cross-sectional view along a cutting plane line X-X of the aerosol-generating article shown in fig. 1;

fig. 3 shows a schematic side cross-sectional view of an aerosol-generating article according to an embodiment of the invention;

fig. 4 shows a schematic side cross-sectional view of an aerosol-generating article according to an embodiment of the invention;

fig. 5 shows a schematic side cross-sectional view of an aerosol-generating article according to an embodiment of the invention;

Fig. 6 shows a schematic side cross-sectional view of an aerosol-generating article according to an embodiment of the invention;

Fig. 7 shows a schematic side cross-sectional view of a part of an aerosol-generating system comprising an aerosol-generating article and an aerosol-generating device as shown in fig. 4, and

Fig. 8 shows a schematic side cross-sectional view of an aerosol-generating article according to an embodiment of the invention.

The aerosol-generating article 1 shown in fig. 1 comprises a strip 12 of aerosol-generating substrate and a downstream section 14 arranged downstream of the strip 12 of aerosol-generating substrate. The aerosol-generating article 1 extends from an upstream or distal end 16 coinciding with the upstream end of the aerosol-generating substrate 12 to a downstream or mouth end 18 coinciding 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 this disclosure.

The aerosol-generating article 1 has an outer diameter of about 7.25 mm.

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

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

The aerosol-generating article 1 further comprises an airflow guiding element 20 extending from an upstream position into the longitudinal matrix cavity 44. The airflow directing element 20 comprises an elongate 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 10mm. The outer diameter of the air flow guiding element 20 is about 3mm. The airflow directing element 20 is made of or comprises cardboard.

The aerosol-generating article 1 also comprises an upstream section 30 arranged upstream of the aerosol-generating substrate 12. In the aerosol-generating article 1, the upstream section 30 comprises 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 an upstream end of the base support element 32. The base support element 32 comprises a porous material, such as cellulose acetate, so as to allow fluid communication between the exterior of the aerosol-generating article 1 and the matrix cavity 44.

The airflow directing element 20 is coupled to and extends downstream from the base support element 32. Thus, the upstream end of the airflow directing element 20 is coupled to the base support element 32, while the downstream end of the airflow directing element 20 defines a free end, as shown in fig. 1. The length of the base support element is about 1mm.

An annular airflow channel 22 is defined between the inner surface of the medium aerosol-generating substrate 12 and the outer surface of the airflow directing element 20. As the user draws on the mouth end 18 of the aerosol-generating article 1, air may be drawn through the base support element 32 via the upstream end 16. The air may then flow through the annular airflow channel 22 and proceed toward the downstream end 18 of the article 1.

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 matrix member 40 is about 1mm. The annular airflow channel 22 has a thickness of about 1.13mm.

Fig. 3 shows another embodiment of the aerosol-generating article 1, wherein the downstream end of the airflow-guiding element 20 is open. This defines a secondary airflow channel 24 extending from the upstream end to the downstream end of the airflow directing element. Air may flow through the porous base support element 32 into the hollow longitudinal cavity defined by the hollow tube of the airflow directing element 20 and exit via its open downstream end. The inner diameter of the airflow directing element 20 shown in figure 3 is about 1.5mm. The inner diameter of the airflow directing element 20 shown in fig. 3 defines the diameter of the secondary airflow passage 24. The airflow directing element 20 is made of or comprises cardboard.

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 directing element 201 has a different configuration. The upstream section 30 includes an upstream element 34 in the form of a hollow tubular element defining a hollow longitudinal cavity extending along its entire length. The upstream element 34 abuts the aerosol-generating substrate 12.

The outer diameter of the base support element 32 is sized such that it is retained 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 laterally spans 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 about 1.5mm. The length of the hollow upstream element 34 is about 5mm. In the embodiment of fig. 4, the outer and inner diameters of the upstream element 34 are the same as the outer and inner diameters of the aerosol-generating element 12 immediately downstream.

The airflow directing element 201 includes an irregular outer surface such that the outer diameter of the airflow directing element 201 varies along its length. An annular airflow channel 22 is similarly defined around the airflow directing element 201. The airflow directing element 201 includes a core elongated portion 21 and a plurality of extension portions 23 extending radially outwardly from the core elongated portion 21. The airflow directing element 201 comprises two extensions 23, a first extension being positioned at the downstream free end of the airflow directing element 201 and a second extension being positioned just upstream of the first extension 23. The extension 23 is spherical. The airflow directing element 201 is made of or comprises cardboard.

The length of the air flow guiding element 201 is about 8mm. The maximum outer diameter or width of the airflow directing element 201 is about 3mm. The minimum outer diameter or width of the airflow directing element 201 is about 1mm. The maximum thickness of the air flow channel 22 is about 1.13mm and the minimum thickness of the air flow channel 22 is about 2.13mm.

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

The airflow directing element 202 is made of or comprises cardboard.

The length of the airflow directing element 202 is about 8mm. The maximum outer diameter or width of the airflow directing element 202 is about 3mm. The minimum outer diameter or width of the airflow directing element 202 is about 1mm. The maximum thickness of the air flow channel 22 is about 1.13mm and the minimum thickness of the air flow channel 22 is about 2.13mm.

Fig. 6 shows another embodiment of an aerosol-generating article 4. The aerosol-generating article 4 differs from the aerosol-generating article 1 shown in fig. 1 in that the airflow-guiding element 203 has a different configuration. The airflow directing element 203 includes an irregular outer surface such that the outer diameter of the airflow directing element 203 varies along its length. The airflow directing element 203 includes a core portion 213 and a plurality of extension portions 233 extending radially outward from the core portion 213. The airflow directing element 203 comprises four extensions 233. The four extensions 234 are cylindrical protrusions evenly spaced along the core portion 213. In this embodiment, the upstream and downstream-most extensions 233 are spaced from the upstream and downstream ends, respectively, of the airflow directing element 203.

The airflow directing element 203 is made of or comprises cardboard.

The length of the airflow directing element 203 is about 8mm. The maximum outer diameter or width of the airflow directing element 203 is about 3mm. The minimum outer diameter or width of the airflow directing element 203 is about 1mm. The maximum thickness of the air flow channel 22 is about 1.13mm and the minimum thickness of the air flow channel 22 is about 2.13mm.

Fig. 7 shows an aerosol-generating system 10 comprising an exemplary aerosol-generating device 100 configured to receive any of the aerosol-generating articles described in the present disclosure. In fig. 7, the aerosol-generating article is the aerosol-generating article 2 shown in fig. 4.

Fig. 7 shows a downstream mouth end portion of the aerosol-generating device 100 at which a device cavity (or heating chamber) is defined and which may receive an aerosol-generating article. The aerosol-generating device 100 comprises a housing (or body) 104 extending between a mouth end 102 and a distal end (not shown). The housing 104 includes a peripheral wall 106. The peripheral wall 106 defines a device cavity for receiving the aerosol-generating article 2. The device lumen is defined by a closed distal end and an open mouth end. The mouth end of the device cavity is located at the mouth end of the aerosol-generating device 100. The aerosol-generating article 2 is configured to be received through the mouth end of the device cavity and to be held within the device cavity. The aerosol-generating device 100 is configured such that, during use, air is configured to enter the device cavity via its upstream end 16 and into the aerosol-generating article.

The aerosol-generating device 100 further comprises a heater 110 and a power supply (not shown) for supplying power to the heater. A controller (not shown) is also provided to control this supply of power to the heater. The heater 110 is configured to controllably heat the aerosol-generating article 2 during use when received within the device 100. The heater 110 is arranged to heat the aerosol-generating substrate 12 of the aerosol-generating article 2 externally during use.

Fig. 8 shows an aerosol-generating article 5 which differs from the aerosol-generating article 3 shown in fig. 5 in that it is not configured to be inserted into and heated by a separate heating device. Alternatively, the upstream section 30 of the aerosol-generating article 4 comprises a combustible heat source 34 and a heat conducting element 36 located between the heat source 34 and the aerosol-generating substrate 36 and in direct contact with the heat source and the aerosol-generating substrate. The heat source 34 defines the upstream end 16 of the aerosol-generating article 5. The aerosol-generating substrate 12 comprises at least one perforation 46 to provide an air inlet into the substrate cavity 44. During use, the combustible heat source 34 is ignited and air may be drawn into the matrix cavity 44 via the air inlet provided by the perforations 46 and downstream toward the mouth 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. Furthermore, the heat conducting element 36 acts as a base support element for the airflow directing element 202. In other words, the upstream end of the airflow directing element 202 is coupled to the downstream end or face of the thermally conductive element 36.

The thermally conductive element 36 comprises a thermally conductive wall 361 between the heat source 34 and the aerosol-generating substrate 36 and two sleeve portions 362, 363. An upstream sleeve portion 362 extends upstream from the perimeter of the thermally conductive wall 361 and is arranged to maintain a 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 an upstream or distal portion of the aerosol-generating substrate 12 in contact with the thermally conductive wall 361. The aerosol-generating article 5 comprises an airflow guiding element 204 having 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 directing element 204 may comprise a thermally conductive material, such as aluminum. Both the thermally conductive wall 361 and the airflow directing element 204 may include the same thermally conductive material.

In all 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 depicted with discontinuous arrows.

For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing quantities, amounts, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Moreover, all ranges include the disclosed maximum and minimum points, and include any intervening ranges therein that may or may not be specifically enumerated herein. Thus, in this context, the number a is understood to be ±10% of a. In this context, the number a may be considered to include values within the general standard error of measurement of the property modified by the number a. In some cases, as used in the appended claims, the number a may deviate from the percentages recited above, provided that the amount of deviation a does not materially affect the basic and novel characteristics of the claimed invention. Moreover, all ranges include the disclosed maximum and minimum points, and include any intervening ranges therein that may or may not be specifically enumerated herein.

The particular embodiments and examples described above illustrate but do not limit the invention. It is to be understood that other embodiments of the invention may be made and that the specific embodiments and examples described herein are not exhaustive.

Claims

1. An aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article comprising:

an aerosol-generating substrate, wherein the aerosol-generating substrate is in the form of a hollow tubular segment defining a substrate cavity extending from an upstream end of the aerosol-generating substrate to a downstream end of the aerosol-generating substrate;

an upstream section located upstream of the aerosol-generating substrate, wherein the upstream section comprises an upstream element adjacent to an upstream end of the aerosol-generating substrate; and

An airflow directing element is provided, wherein the airflow directing element is coupled to the upstream element and extends longitudinally into the substrate cavity, and wherein an airflow channel is defined between an outer surface of the airflow directing element and an inner surface of the aerosol-generating substrate.

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

3. An aerosol-generating article according to claim 1 or 2, wherein the width or diameter of the airflow directing element varies along its length.

4. An aerosol-generating article according to any preceding claim, wherein the outer surface of the airflow directing element is textured or non-uniform.

5. An aerosol-generating article according to any preceding claim, wherein the airflow directing element extends along at least 50% of the length of the substrate cavity.

6. An aerosol-generating article according to any preceding claim, wherein the airflow directing element comprises a hollow tube.

7. An aerosol-generating article according to any preceding claim, wherein the airflow directing element comprises an elongated body comprising a central core portion and an extension portion positioned along the core portion, wherein the extension portion extends outwardly from the core portion.

8. An aerosol-generating article according to claim 7, wherein the airflow directing element comprises at least two extension portions located along the core portion.

9. An aerosol-generating article according to any preceding claim, further comprising a base support element located upstream of the aerosol-generating substrate, and wherein the airflow directing element extends from the base support element.

10. An aerosol-generating article according to claim 9, wherein the base support element is porous or comprises at least one orifice such that fluid communication is established between the exterior of the aerosol-generating article and the interior of the aerosol-generating substrate via the base support element.

11. An aerosol-generating article according to any preceding claim, wherein the airflow directing element comprises an airflow inlet at a first position and an airflow outlet at a second position downstream of the first position, such that an airflow path is defined within and along the airflow directing element.

12. An aerosol-generating article according to any preceding claim, wherein the wall thickness of the aerosol-generating substrate is between 5% and 40% of the outer diameter of the aerosol-generating substrate.

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

14. An aerosol-generating article according to any preceding claim, wherein the airflow directing element does not contact an inner surface of the aerosol-generating substrate.

15. An aerosol generating system, comprising an aerosol generating article and an aerosol generating device according to any one of the preceding claims, the aerosol generating device comprising a heating chamber for receiving the aerosol generating article and a heating element arranged at or around the periphery of the heating chamber.