WO2025242518A1

WO2025242518A1 - Aerosol-generating article with aerosol-generating element including core body and shell portion

Info

Publication number: WO2025242518A1
Application number: PCT/EP2025/063322
Authority: WO
Inventors: Marc Antonius Friedrich VAN DEN BOOGAART
Original assignee: Philip Morris Products SA
Current assignee: Philip Morris Products SA
Priority date: 2024-05-21
Filing date: 2025-05-15
Publication date: 2025-11-27
Anticipated expiration: 2026-11-21

Abstract

AEROSOL-GENERATING ELEMENT FOR USE IN AN AEROSOL-GENERATING ARTICLE OR SYSTEM There is provided an aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article comprising: a longitudinally extending aerosol-generating element; and a downstream section at a location downstream of the aerosol-generating element. The aerosol-generating element comprises a core body and an air-permeable shell portion circumscribing the core body, the shell portion comprising a primary aerosol-generating substrate and defining an airflow path through the shell portion. The core body is substantially free of the primary aerosol-generating substrate. A cross-sectional area of the core body is at least 3 percent of an overall cross-sectional area of the aerosol-generating element. (Figure 1)

Description

AEROSOL-GENERATING ARTICLE WITH AEROSOL-GENERATING ELEMENT INCLUDING CORE BODY AND SHELL PORTION

The present invention relates to an aerosol-generating article comprising an aerosolgenerating element including a core body and a shell portion circumscribing the core body. The present disclosure also relates to an aerosol-generating system comprising the aerosolgenerating article and an aerosol-generating device configured to heat the aerosol-generating article.

Aerosol-generating articles in which an aerosol-generating substrate, such as a tobaccocontaining substrate, is heated rather than combusted, are known in the art. Typically in such articles an aerosol is generated by the transfer of heat from a heat source to a physically separate aerosol-generating substrate or material, which may be located in contact with, within, around, or downstream of the heat source. During use of the aerosol-generating article, volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source and are entrained in air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol.

Substrates for heated aerosol-generating articles have, in the past, often been produced using randomly oriented shreds, strands, or strips of tobacco material. As an alternative, rods for heated aerosol-generating articles formed from gathered sheets of tobacco material have been disclosed, by way of example, in international patent application WO 2012/164009. Plant materials other than tobacco materials have also been proposed for use as aerosol-generating substrate in aerosol-generating articles. For example, aerosol-generating substrates including plant particles derived from ground or powdered leaf lamina, fruits, stalks, stems, roots, seeds, buds or bark or any other suitable portion of the plant. Among others, substrates including particles of eucalyptus, mint, chamomile, clove, star anise, have been described.

Substrates for heated aerosol-generating articles typically further comprise an aerosol former, that is, a compound or mixture of compounds that, in use, facilitates formation of the aerosol and that preferably is substantially resistant to thermal degradation at the operating temperature of the aerosol-generating article.

A number of prior art documents disclose aerosol-generating devices for consuming aerosol-generating articles. Such devices include, for example, electrically heated aerosolgenerating devices in which an aerosol is generated by the transfer of heat from one or more electrical heater elements of the aerosol-generating device to the aerosol-generating substrate of a heated aerosol-generating article.

For example, devices have been described that include a heating chamber for at least partly receiving the aerosol-generating article and one or more heating elements - such as, for example, a plurality of electrically resistive, heating elements - provided at or about a periphery of the heating chamber. In such an arrangement, the heating elements are often described as being “external”, because during use they are positioned externally of the aerosol-generating substrate, and so heat is supplied from the outside into the aerosolgenerating substrate.

This is in contrast to other known devices which comprise a heater element configured to be positioned within the aerosol-generating substrate during use (that is, an “internal” heating element), such that heat is supplied from the inside of the aerosol-generating substrate. For example, aerosol-generating devices are known which comprise an elongate heater element configured to be inserted into the aerosol-generating substrate when the aerosol-generating article is received into the heating chamber. Further, aerosol-generating devices are known wherein heating of the aerosol-generating substrate is achieved inductively by means of a susceptor element provided within the aerosol-generating substrate.

In devices relying on an external heating arrangement, a thermal gradient is typically established across the aerosol-generating substrate during use. Since the aerosol-generating substrate typically has relatively poor thermal transfer properties, it is difficult to supply heat uniformly across the entirety of the aerosol-generating substrate, and particularly so in the regions of it that are farther away from the heat source. In general, the more peripheral regions of the aerosol-generating substrate, which are closest to the heating elements, receive a greater amount of thermal energy - and therefore reach a higher temperature - than the innermost regions of the aerosol-generating substrate.

As a consequence, regions of the aerosol-generating substrate that are farther away from the heating elements may struggle or altogether fail to reach a temperature high enough to promote release of aerosol species. Some of the aerosol-generating substrate may therefore be used less than fully efficiently, or may fail to contribute to aerosol generation and delivery altogether. By contrast, the regions of the aerosol-generating substrate that are closest to the heating elements may overheat, which may have an undesirable impact on the quality of the aerosol delivered to the consumer. In general, the performance of such a system may become significantly inconsistent in terms of aerosol generation and delivery from one inhalation to the next.

Thus, it would be desirable to provide an aerosol-generating article that enables the provision of a consistently satisfactory aerosol delivery to the consumer during use, even when the aerosol-generating article is used in an aerosol-generating device comprising an external heating arrangement. Further, it would be desirable to provide one such improved aerosolgenerating article that is perceived by the consumer as having a satisfactory resistance to draw (RTD). It would also be desirable to provide one such aerosol-generating article that can be manufactured efficiently and at high speed, preferably with a low RTD variability from one article to another.

The present invention aims at providing a technical solution adapted to achieve at least one of the desirable results described above.

The present disclosure relates to an aerosol-generating article for generating an inhalable aerosol upon heating.

The aerosol-generating article may comprise a longitudinally extending aerosolgenerating element.

The aerosol-generating article may further comprise a downstream section at a location downstream of the aerosol-generating element.

The aerosol-generating element may comprise a core body and an air-permeable shell portion circumscribing the core body.

The shell portion may comprise a primary aerosol-generating substrate.

The shell portion may define an airflow path through the shell portion.

The core body may be substantially free of the primary aerosol-generating substrate.

A cross-sectional area of the core body may be at least 3 percent of an overall cross- sectional area of the aerosol-generating element.

According to a first aspect of the present invention, there is provided an aerosolgenerating article for generating an inhalable aerosol upon heating, the aerosol-generating article comprising: a longitudinally extending aerosol-generating element; and a downstream section at a location downstream of the aerosol-generating element; wherein the aerosolgenerating element comprises a core body and an air-permeable shell portion circumscribing the core body, the shell portion comprising a primary aerosol-generating substrate and defining an airflow path through the shell portion; wherein the core body is substantially free of the primary aerosol-generating substrate; and wherein a cross-sectional area of the core body is at least 3 percent of an overall cross-sectional area of the aerosol-generating element.

According to a second aspect of the present invention, there is provided an aerosolgenerating system for producing an inhalable aerosol, the aerosol-generating system comprising: an aerosol-generating article according to the first aspect of the present invention, and an aerosol-generating device comprising a heating arrangement configured to heat at least a portion of the aerosol-generating substrate to generate an aerosol.

The term “aerosol-generating article” is used herein with reference to the invention to describe an article wherein an aerosol-generating substrate is heated to produce and deliver an aerosol to a consumer. As used herein, the term “aerosol-generating substrate” denotes a substrate capable of releasing volatile compounds upon heating to generate an aerosol. The term “aerosol-generating element” is used herein with reference to the invention to describe a component of an aerosol-generating article that comprises aerosol-generating substrate and is therefore, in turn, configured to release volatile compounds upon heating to generate an aerosol. As will become apparent from the following description, an aerosolgenerating element may further comprise material that, in contrast to the aerosol-generating substrate, is not directly involved in the generation and delivery of aerosol to a consumer. That is, the aerosol-generating element may further comprise material that is substantially inert from an aerosol generation viewpoint.

In the context of the present invention, the expression “primary aerosol-generating substrate” is used to denote the main source of volatile compounds that are releasable upon heating to generate an aerosol.

Thus, the primary aerosol-generating substrate accounts for at least 51 percent by weight of all the volatile compounds that are provided within the aerosol-generating article and are releasable upon heating to generate an aerosol.

In some embodiments, the primary aerosol-generating substrate accounts for at least 60 percent by weight of all the volatile compounds that are provided within the aerosolgenerating article and are releasable upon heating to generate an aerosol. Preferably, the primary aerosol-generating substrate accounts for at least 70 percent by weight or 80 percent by weight or 90 percent by weight of all the volatile compounds that are provided within the aerosol-generating article and are releasable upon heating to generate an aerosol.

In certain embodiments, the “primary aerosol-generating substrate” may in fact be the sole source of volatile compounds that are releasable upon heating to generate an aerosol.

However, in other embodiments, in addition to the primary aerosol-generating substrate, the aerosol-generating article may comprise one or more secondary sources of volatile compounds that may similarly be releasable upon heating to generate an aerosol.

In those embodiments, the one or more secondary sources of volatile compounds that may be releasable upon heating to generate an aerosol may account for at least 1 percent by weight of all the volatile compounds that are provided within the aerosol-generating article and are releasable upon heating to generate an aerosol, preferably at least 2 percent by weight of all the volatile compounds that are provided within the aerosol-generating article and are releasable upon heating to generate an aerosol, more preferably at least 3 percent of all the volatile compounds that are provided within the aerosol-generating article and are releasable upon heating to generate an aerosol. As described above, the core body is substantially free of the primary aerosol-generating substrate. However, as will be discussed in more detail below, the core body may comprise one of the one or more secondary sources of volatile compounds that may be releasable upon heating to generate an aerosol, in those embodiments comprising such a secondary source of volatile compounds. A conventional cigarette is lit when a user applies a source of ignition to one end of the cigarette and draws air through the other end. The localised heat provided by the flame and the oxygen in the air drawn through the cigarette causes the end of the cigarette to ignite, and the resulting combustion generates an inhalable smoke. By contrast, in heated aerosolgenerating articles, an aerosol is generated by heating a flavour generating substrate, such as, for example, a tobacco-based substrate or a substrate containing an aerosol-former and a flavouring.

Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles in which an aerosol is generated by the transfer of heat from a combustible fuel element or heat source to a physically separate aerosol forming material. For example, aerosol-generating articles according to the invention may find particular application in aerosol-generating systems comprising an electrically heated aerosol-generating device including a heater element which is adapted to supply heat to the aerosol-generating substrate of the aerosol-generating element.

As used herein with reference to the invention, the term “aerosol-generating device” is used to describe a device that interacts with the aerosol-generating substrate of the aerosolgenerating article to generate an aerosol. As will be discussed in more detail below, aerosolgenerating articles according to the invention are particularly suited for use in aerosolgenerating systems comprising an electrically heated aerosol-generating device including one or more heater element positioned externally of the aerosol-generating substrate during use.

Upon heating, volatile compounds are released from the aerosol-generating element and entrained in air drawn through the aerosol-generating article. As the released compounds cool they condense to form an aerosol that is inhaled by the consumer. The aerosol generated upon heating the aerosol-generating substrate is a dispersion of solid particles or liquid droplets (or a combination of solid particles and liquid droplets) in a gas. The aerosol may be visible or invisible and may include vapours of substances that are ordinarily liquid or solid at room temperature as well as solid particles or liquid droplets or a combination of solid particles and liquid droplets.

As used herein, the terms ‘“distal”, “upstream” “proximal” and “downstream” describe the relative positions of components, or portions of components, of an aerosol-generating article or aerosol generating device. Aerosol generating articles and devices according to the present disclosure have a proximal end through which, in use, an aerosol exits the article or device for delivery to a user, and have an opposing distal end. The proximal end of the aerosol generating article and device may also be referred to as the mouth end. In use, a user draws on the proximal end of the aerosol generating article in order to inhale the aerosol generated by the aerosol generating article or device. The terms upstream and downstream are relative to the direction of aerosol movement through the aerosol generating article or aerosol- generating device when a user draws on the proximal end of the aerosol-generating article. The proximal end of the aerosol-generating article is downstream of the distal end of the aerosol-generating article. The proximal end of the aerosol-generating article may also be referred to as the downstream end of the aerosol-generating article and the distal end of the aerosol-generating article may also be referred to as the upstream end of the aerosolgenerating article.

As used herein with reference to the invention, the term “longitudinal” is used to describe the direction between the upstream end and the downstream end of the aerosolgenerating article or between the upstream end and the downstream end of the aerosolgenerating device. During use, air is drawn through the aerosol-generating article in the longitudinal direction.

As used herein with reference to the invention, the term “length” is used to describe the maximum dimension of the aerosol-generating article or the aerosol-generating device or a component of the aerosol-generating article or the aerosol-generating device in the longitudinal direction.

As used herein with reference to the invention, the term “transverse” is used to describe the direction perpendicular to the longitudinal direction. Unless otherwise stated, references to the “cross-section” of the aerosol-generating article or aerosol-generating device or a component of the aerosol-generating article or aerosol-generating device refer to the transverse cross-section.

As used herein with reference to the invention, the term “width” denotes the maximum dimension of the aerosol-generating article or device or of a component of the aerosolgenerating article or device in a transverse direction. For example, where the aerosolgenerating article has a substantially circular cross-section, the width of the aerosolgenerating article corresponds to the diameter of the aerosol-generating article. Where a component of the aerosol-generating article has a substantially circular cross-section, the width of the component of the aerosol-generating article substantially corresponds to the diameter of the component of the aerosol-generating article.

As used herein, the term “air-permeable” is used to describe an entity which allows air to pass through it. The term “air-permeable” also encompasses a volume characteristic of a suitable material, either in relation to all or part of its volume; for example, a material having open porosity in all or part of the volume of the material.

Thus, the term “air-permeable portion”, as used herein with reference to the present invention, denotes a portion of a component that is not blocked, plugged or sealed in a way to completely block air from passing through the portion.

An air-permeable portion of a component may be configured so as to enable flow along a desired airflow direction. For example, an air-permeable portion of a component may be configured so as to enable flow from a first end of the air-permeable portion to a second end of the air-permeable portion longitudinally opposite the first end of the air-permeable portion.

To enable flow along a desired airflow direction, the air-permeable portion may comprise one or more airflow channels extending through the air-permeable portion. For example, the air-permeable portion may comprise one or more airflow channels extending from a first end of the air-permeable portion to a second end of the air-permeable portion opposite the first end of the air-permeable portion.

The one or more airflow channels of the air-permeable portion may be arranged within the air-permeable body portion in regular and orderly fashion. For example, the air-permeable portion may define a plurality of substantially longitudinal airflow channels extending parallel to each other. In particular, the air-permeable portion may have a honeycomb structure. The void fraction and cross-sectional porosity of such an air-permeable body portion are easy to define and control by adjusting the number and size of airflow channels in the honeycomb structure.

The air-permeable body portion may otherwise define the one or more airflow channels in a non-regular and generally non-orderly fashion. For example, the air-permeable portion may be a portion of a body which has a plurality of pores, at least some of which are interconnected and open to the outside of the portion. Such a porous portion of a component may generally define an airflow path through the porous portion, so that a fluid may be able to flow from one end surface of the porous portion to a second end surface of the porous portion opposite the first end surface. In general, a pressure drop across such a porous portion will be greater than a pressure drop across a hollow tubular element having the same length of the porous portion and a free cross-sectional area equal to an overall cross-sectional area of the porous portion. Thus, flow across the porous portion will generally be partially restricted compared to flow through a hollow tubular element of comparable dimensions.

As briefly described above, in contrast with existing aerosol-generating elements, an aerosol-generating article in accordance with the present invention comprises a longitudinally extending aerosol-generating element comprising a core body and an air-permeable shell portion circumscribing the core body, wherein the shell portion comprises a primary aerosolgenerating substrate and defines an airflow path through the shell portion, and wherein the core body is substantially free of the primary aerosol-generating substrate, a cross-sectional area of the core body being at least 3 percent of an overall cross-sectional area of the aerosolgenerating element.

Since the primary aerosol-generating substrate is present in the shell portion but not in the core body, it is advantageously possible to achieve a much more homogenous heat distribution throughout the primary aerosol-generating substrate, so that compared with existing aerosol-generating articles, a temperature gradient induced by an external heating arrangement has a significantly reduced impact on aerosol generation and delivery. Without wishing to be bound by theory, it is understood that, compared with existing aerosol-generating articles, a greater proportion of the primary aerosol-generating substrate contained in an aerosol-generating article according to the present invention can be efficiently heated during use to a temperature conducive to the release of aerosol species. As a result, an overall efficiency of use of the primary aerosol-generating substrate is achieved. As will be discussed in more detail below, by adjusting a ratio between the cross-sectional area of the core body and the cross-sectional area of the aerosol-generating element as a whole, it may be possible to particularly improve the efficiency of use of the primary aerosol-generating substrate, as a greater fraction of the primary aerosol-generating substrate present in the aerosol-generating article is positioned at a location that is easier to heat more homogenously and consistently.

Being able to heat homogenously a greater fraction of the primary aerosol-generating substrate has the additional benefit that aerosol generation can be kept more consistent during use from one inhalation to the next. Further, it is easier to provide the consumer with a consistent aerosol delivery and overall performance of the aerosol-generating article from one aerosol-generating article to the next, for example in the same package.

Additionally, the present invention provides a novel arrangement that may facilitate fine- tuning of the RTD of the aerosol-generating article, as it may generally be easier to accurately control the RTD of the core body. By contrast, especially where an aerosol-generating element is essentially formed of an aerosol-generating substrate comprising a naturally occurring material, such as for example a plant material, variations in density, porosity, etc. may have a more significant impact on an overall RTD of the aerosol-generating element.

Further, air-permeability of the core body may be selected such as to direct more or less of the air drawn into the aerosol-generating article to flow through the aerosol-generating substrate contained in the shell portion. For example, in an aerosol-generating article in accordance with the present invention the core body may be configured to be substantially air-impervious, and so substantially all the air drawn into the aerosol-generating article is entirely directed to flow through the aerosol-generating substrate in the shell portion. This can also contribute to a more efficient extraction and delivery of aerosol species during use.

Aerosol-generating articles in accordance with the present invention can be manufactured at high speed using existing equipment, as forming an aerosol-generating element as described above only requires minor modifications of known processes for combining components of aerosol-generating articles. This is desirable as the existing production lines may easily and rapidly adapted to accommodate for the manufacture of aerosol-generating articles according to the present invention.

As discussed above, in aerosol-generating articles according to the present invention the aerosol-generating substrate present in the shell portion but not in the core body provides a main source of aerosol-forming volatile species. However, the arrangement of the present invention does not exclude the possibility that one or more further aerosol-forming components (such as, for example, in the form of a flavour thread) be provided at a location within the core body. The further aerosol-forming component may thus provide a different, secondary source of aerosol-forming volatile species in the same aerosol-generating article. Accordingly, in addition to providing one or more of the benefits described above, certain embodiments of aerosol-generating articles according to the present invention may advantageously present the consumer with novel flavour delivery profiles if, for example, the aerosol-generating substrate and the further aerosol-forming component are releasable at different temperatures, and so forth.

As described briefly above, aerosol-generating articles according to the present invention comprise a longitudinally extending aerosol-generating element. The elongate aerosol-generating element comprises a shell portion comprising an aerosol-generating substrate.

The aerosol-generating substrate may be a solid aerosol-generating substrate.

In some embodiments, the aerosol-generating substrate comprises a plant material, such as tobacco plant material.

Particularly suitable types of materials for use in the aerosol-generating substrate are described below and include, for example, tobacco cut filler, homogenised tobacco material such as cast leaf, aerosol-generating films and gel compositions.

The aerosol-generating substrate preferably comprises an aerosol former. Suitable aerosol formers are for example: polyhydric alcohols such as, for example, triethylene glycol, 1 ,3-butanediol, propylene glycol and glycerine; esters of polyhydric alcohols such as, for example, glycerol mono-, di- or triacetate; aliphatic esters of mono-, di- or polycarboxylic acids such as, for example, dimethyl dodecanedioate and dimethyl tetradecanedioate; and combinations thereof.

Preferably, the aerosol former comprises one or more of glycerine and propylene glycol. The aerosol former may consist of glycerine or propylene glycol or of a combination of glycerine and propylene glycol.

In certain embodiments, the aerosol-generating substrate preferably comprises at least 5 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate, more preferably at least 10 percent by weight on a dry weight basis, more preferably at least 15 percent by weight on a dry weight basis. In such embodiments, the aerosolgenerating substrate preferably comprises no more than 30 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate, more preferably no more than 25 percent by weight on a dry weight basis, more preferably no more than 20 percent by weight on a dry weight basis. For example, the aerosol former content of the aerosol- generating substrate may be between 5 percent and 30 percent by weight, or between 10 percent and 25 percent by weight, or between about 15 percent and about 20 percent by weight, on a dry weight basis. In such embodiments, the aerosol former content is therefore relatively low.

In other embodiments, the aerosol-generating substrate preferably comprises at least 40 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate, more preferably at least 45 percent by weight on a dry weight basis, more preferably at least 50 percent by weight on a dry weight basis. In such embodiments, the aerosolgenerating substrate preferably comprises no more than 80 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate, more preferably no more than 75 percent by weight on a dry weight basis, more preferably no more than 70 percent by weight on a dry weight basis. For example, the aerosol former content of the aerosolgenerating substrate may be between 40 percent and 80 percent by weight, or between 45 percent and 75 percent by weight, or between about 50 percent and about 70 percent by weight, on a dry weight basis. In such embodiments, the aerosol former content is therefore relatively high.

In some preferred embodiments, the aerosol-generating substrate comprises tobacco material. For example, the aerosol-generating substrate may comprise shredded tobacco material. For example, the shredded tobacco material may be in the form of cut filler, as described in more detail below. Alternatively, the shredded tobacco material may be in the form of a shredded sheet of homogenised tobacco material. Suitable homogenised tobacco materials for use in the present invention are described below.

Within the context of the present specification, the term “cut filler” is used to describe to a blend of shredded plant material, such as tobacco plant material, including, in particular, one or more of leaf lamina, processed stems and ribs, homogenised plant material.

The cut filler suitable to be used with the present invention generally may resemble cut filler used for conventional smoking articles. The cut width of the cut filler preferably may be between 0.3 millimetres and 2.0 millimetres, or between 0.5 millimetres and 1.2 millimetres, or between 0.6 millimetres and 0.9 millimetres.

Preferably, the strands have a length of between about 10 millimetres and about 40 millimetres before the strands are collated to form the rod of aerosol-generating substrate.

Preferably, the cut filler is soaked with the aerosol former. Soaking the cut filler can be done by spraying or by other suitable application methods. Preferably, the aerosol former in the cut filler comprises one or more of glycerol and propylene glycol. The aerosol former may consist of glycerol or propylene glycol or of a combination of glycerol and propylene glycol.

In other preferred embodiments, the aerosol-generating substrate comprises homogenised plant material, preferably a homogenised tobacco material. As used herein, the term “homogenised plant material” encompasses any plant material formed by the agglomeration of particles of plant. For example, sheets or webs of homogenised tobacco material for the aerosol-generating substrates of the present invention may be formed by agglomerating particles of tobacco material obtained by pulverising, grinding or comminuting plant material and optionally one or more of tobacco leaf lamina and tobacco leaf stems. The homogenised plant material may be produced by casting, extrusion, paper making processes or other any other suitable processes known in the art.

The homogenised plant material can be provided in any suitable form.

In some embodiments, the homogenised plant material may be in the form of one or more sheets. As used herein with reference to the invention, the term “sheet” describes a laminar element having a width and length substantially greater than the thickness thereof.

The homogenised plant material may be in the form of a plurality of pellets or granules.

The homogenised plant material may be in the form of a plurality of strands, strips or shreds. As used herein, the term “strand” describes an elongate element of material having a length that is substantially greater than the width and thickness thereof.

The aerosol former content of the homogenised tobacco material is preferably within the ranges defined above for aerosol-generating substrate having a relatively low aerosol former content.

In other preferred embodiments, the aerosol-generating substrate is in the form of an aerosol-generating film comprising a cellulosic based film-forming agent, nicotine and the aerosol former. The aerosol-generating film may further comprise a cellulose based strengthening agent. The aerosol-generating film may further comprise water, preferably 30 percent by weight of less of water.

As used herein, the term “film” is used to describe a solid laminar element having a thickness that is less than the width or length thereof. The film may be self-supporting.

In the context of the present invention the term “cellulose based film-forming agent” is used to describe a cellulosic polymer capable, by itself or in the presence of an auxiliary thickening agent, of forming a continuous film. Preferably, the cellulose based film-forming agent is selected from the group consisting of hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), ethyl cellulose (EC), hydroxyethyl methyl cellulose (HEMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), and combinations thereof. In particularly preferred embodiments, the cellulose based film-forming agent is HPMC.

The aerosol former content of the aerosol-generating film is within the ranges defined above for aerosol-generating substrates having a relatively high aerosol former content.

Suitable aerosol-generating films for use as the aerosol-generating substrate of aerosolgenerating articles according to the invention are described in WO-A-2020/207733 and WO- A-2022/074157. Preferably, the aerosol-generating film comprises between 0.5 percent and 10 percent by weight of nicotine, or between 1 percent and 8 percent by weight of nicotine, or between 2 percent and 6 percent by weight of nicotine, on a dry weight basis.

The aerosol-generating film may be a substantially tobacco-free aerosol-generating film.

In alternative embodiments of the invention, the aerosol-generating substrate may comprise a gel composition that includes nicotine, at least one gelling agent and the aerosol former. The gel composition is preferably substantially tobacco free.

The preferred weight ranges for nicotine in the gel composition are the same as those defined above in relation to aerosol-generating films.

Suitable gel compositions for use as the aerosol-generating substrate of aerosolgenerating articles according to the invention are described in WO-A-2021/170642.

The gel composition preferably comprises at least 50 percent by weight of aerosol former, more preferably at least 60 percent by weight, more preferably at least 70 percent by weight of aerosol former, on a dry weight basis. The gel composition may comprise up to 80 percent by weight of aerosol former. The aerosol former in the gel composition is preferably glycerol.

In certain embodiments of the invention, the aerosol-generating article further comprises one or more elongate susceptor elements within the rod of aerosol-generating substrate. For example, one or more elongate susceptor elements may be arranged substantially longitudinally within the rod of aerosol-generating substrate and in thermal contact with the aerosol-generating substrate.

As used herein with reference to the present invention, the term “susceptor element” refers to a material that can convert electromagnetic energy into heat.

Suitable susceptor elements for use in the aerosol-generating substrate of aerosolgenerating articles according to the present invention are described in WO-A-2021/170673.

Preferably, the shell portion comprises a wrapper circumscribing the aerosol-generating substrate. The wrapper may be a paper wrapper or a non-paper wrapper. Suitable paper wrappers for use in specific embodiments of the invention are known in the art and include, but are not limited to: cigarette papers; and filter plug wraps. Suitable non-paper wrappers for use in specific embodiments of the invention are known in the art and include, but are not limited to sheets of homogenised tobacco materials.

The shell portion has an upstream end surface at an upstream end and a downstream end surface at a downstream end. Further, the shell portion has an inner surface and an outer surface which extend longitudinally between the upstream end surface and the downstream end surface. Depending on the shape of a cross-section of the shell portion body, the inner and outer surfaces may comprise one or more wall portions. For example, in the case of a tubular shell portion body having a circular cross-section, both outer and inner surfaces are defined by respective cylindrical walls.

An equivalent outer diameter of the shell portion may for example be up to 12 millimetres. Preferably, an equivalent outer diameter of the shell portion is less than or equal to 10 millimetres. More preferably, an equivalent outer diameter of the shell portion is less than or equal to 8 millimetres. Even more preferably, an equivalent outer diameter of the shell portion is less than or equal to 7.5 millimetres.

An equivalent outer diameter of the shell portion may for example be at least 4 millimetres. Preferably, an equivalent outer diameter of the shell portion is at least 4.5 millimetres. More preferably, an equivalent outer diameter of the shell portion is at least 5 millimetres. Even more preferably, an equivalent outer diameter of the shell portion is at least 5.5 millimetres.

In some embodiments, an equivalent outer diameter of the shell portion is from 4 millimetres to 10 millimetres, preferably from 4.5 millimetres to 10 millimetres, more preferably from 5 millimetres to 10 millimetres, even more preferably from 5.5 millimetres to 10 millimetres. In other embodiments, an equivalent outer diameter of the shell portion is from 4 millimetres to 8 millimetres, preferably from 4.5 millimetres to 8 millimetres, more preferably from 5 millimetres to 8 millimetres, even more preferably from 5.5 millimetres to 8 millimetres. In further embodiments, an equivalent outer diameter of the shell portion is from 4 millimetres to 7.5 millimetres, preferably from 4.5 millimetres to 7.5 millimetres, more preferably from 5 millimetres to 7.5 millimetres, even more preferably from 5.5 millimetres to 7.5 millimetres.

An equivalent inner diameter of the shell portion is at least as large as an equivalent diameter of the core portion, which will be described in more detail below.

The shell portion and the core body have preferably the same length, and so a length of the aerosol-generating element preferably is also equal to the length of the core body and to the length of the shell portion.

A length of the aerosol-generating element may be at least 10 millimetres. Preferably, a length of the aerosol-generating element is at least 12 millimetres. More preferably, a length of the aerosol-generating element may be at least 15 millimetres, even more preferably at least 20 millimetres.

A length of the aerosol-generating element may for example be up to 80 millimetres. Preferably, a length of the aerosol-generating element is less than or equal to 75 millimetres. More preferably, a length of the aerosol-generating element is less than or equal to 70 millimetres or even less than or equal to 60 millimetres, such as less than or equal to 50 millimetres. In some embodiments, a length of the aerosol-generating element is from 10 millimetres to 80 millimetres, preferably from 12 millimetres to 80 millimetres, more preferably from 15 millimetres to 80 millimetres, even more preferably from 20 millimetres to 80 millimetres.

In other embodiments, a length of the aerosol-generating element is from 10 millimetres to 75 millimetres, preferably from 12 millimetres to 75 millimetres, more preferably from 15 millimetres to 75 millimetres, even more preferably from 20 millimetres to 75 millimetres.

In further embodiments, a length of the aerosol-generating element is from 10 millimetres to 70 millimetres, preferably from 12 millimetres to 70 millimetres, more preferably from 15 millimetres to 70 millimetres, even more preferably from 20 millimetres to 70 millimetres.

In yet further embodiments, a length of the aerosol-generating element is from 10 millimetres to 60 millimetres, preferably from 12 millimetres to 60 millimetres, more preferably from 15 millimetres to 60 millimetres, even more preferably from 20 millimetres to 60 millimetres.

In some preferred embodiments, a length of the aerosol-generating element is from 10 millimetres to 50 millimetres, preferably from 12 millimetres to 50 millimetres, more preferably from 15 millimetres to 50 millimetres, even more preferably from 20 millimetres to 50 millimetres.

In aerosol-generating articles according with the present invention, the core body extends longitudinally within the aerosol-generating element. Preferably, the core body extends all the way from an upstream end of the aerosol-generating element to a downstream end of the aerosol-generating element. In other words, a length of the core body is preferably substantially the same as a length of the aerosol-generating element and as a length of the shell portion.

The core body has an upstream end surface at an upstream end and a downstream end surface at a downstream end. Further, the core body has a lateral surface extending longitudinally between the upstream end surface and the downstream end surface. Depending on the shape of a cross-section of the core body, the lateral surface may comprise one or more peripheral walls. For example, in the case of a cylindrical core body that has a circular cross-section, the lateral surface is defined by a single cylindrical wall. In another example, where the core body is parallelepiped-shaped or prism-shaped, the lateral surface is defined by the surfaces of the lateral faces of the parallelepiped or prism.

Preferably, the upstream end surface of the core body defines part of an upstream end surface of the aerosol-generating element and the downstream end surface of the core body defines part of a downstream end surface of the aerosol-generating element. As described briefly above, in aerosol-generating article according to the present invention a cross-sectional area of the core body may be at least 3 percent of an overall cross- sectional area of the aerosol-generating element.

Preferably, a cross-sectional area of the core body is at least 5 percent of an overall cross-sectional area of the aerosol-generating element. More preferably, a cross-sectional area of the core body is at least 10 percent of an overall cross-sectional area of the aerosolgenerating element. Even more preferably, a cross-sectional area of the core body is at least 12 percent of an overall cross-sectional area of the aerosol-generating element.

A cross-sectional area of the core body may be up to 35 percent of an overall cross- sectional area of the aerosol-generating element.

Preferably, a cross-sectional area of the core body is less than or equal to 30 percent of an overall cross-sectional area of the aerosol-generating element. More preferably, a cross- sectional area of the core body is less than or equal to 25 percent of an overall cross-sectional area of the aerosol-generating element. Even more preferably, a cross-sectional area of the core body is less than or equal to 20 percent of an overall cross-sectional area of the aerosolgenerating element.

In some embodiments, a cross-sectional area of the core body is from 3 percent to 35 percent of an overall cross-sectional area of the aerosol-generating element, preferably from 3 percent to 30 percent of an overall cross-sectional area of the aerosol-generating element, more preferably from 3 percent to 25 percent of an overall cross-sectional area of the aerosolgenerating element, even more preferably from 3 percent to 20 percent of an overall cross- sectional area of the aerosol-generating element.

In other embodiments, a cross-sectional area of the core body is from 5 percent to 35 percent of an overall cross-sectional area of the aerosol-generating element, preferably from 5 percent to 30 percent of an overall cross-sectional area of the aerosol-generating element, more preferably from 5 percent to 25 percent of an overall cross-sectional area of the aerosolgenerating element, even more preferably from 5 percent to 20 percent of an overall cross- sectional area of the aerosol-generating element.

In further embodiments, a cross-sectional area of the core body is from 10 percent to 35 percent of an overall cross-sectional area of the aerosol-generating element, preferably from 10 percent to 30 percent of an overall cross-sectional area of the aerosol-generating element, more preferably from 10 percent to 25 percent of an overall cross-sectional area of the aerosolgenerating element, even more preferably from 10 percent to 20 percent of an overall cross- sectional area of the aerosol-generating element.

In yet further embodiments, a cross-sectional area of the core body is from 12 percent to 35 percent of an overall cross-sectional area of the aerosol-generating element, preferably from 12 percent to 30 percent of an overall cross-sectional area of the aerosol-generating element, more preferably from 12 percent to 25 percent of an overall cross-sectional area of the aerosol-generating element, even more preferably from 12 percent to 20 percent of an overall cross-sectional area of the aerosol-generating element.

In aerosol-generating articles wherein a ratio between the cross-sectional area of the core body and the overall cross-sectional area of the aerosol-generating element falls within the ranges described above, it is advantageously possible to ensure that a significantly larger proportion of the aerosol-generating substrate contained within the aerosol-generating element is heated homogenously enough to provide a consistent aerosol generation and delivery during use.

In some embodiments, an equivalent diameter of the core body is at least 1.25 millimetres. The term “equivalent diameter of the core body” is used herein to denote the diameter of the cylinder which has the same volume as the core body. In general, the cross section of the core body may have any shape, although a circular or quasi-circular shape, such as an oval shape or elliptical shape is preferred. For a cylindrical core body having a circular transverse cross-section, the equivalent diameter is the diameter of the cross-section of the core body.

Preferably, an equivalent diameter of the core body is at least 1.5 millimetres. More preferably, an equivalent diameter of the core body is at least 2.0 millimetres. Even more preferably, an equivalent diameter of the core body is at least 2.25 millimetres.

An equivalent diameter of the core body may for example be up to 3.5 millimetres.

Preferably, an equivalent diameter of the core body is less than or equal to 3.0 millimetres. More preferably, an equivalent diameter of the core body is less than or equal to 2.75 millimetres. Even more preferably, an equivalent diameter of the core body is less than or equal to 2.5 millimetres.

In some embodiments, an equivalent diameter of the core body is from 1.25 millimetres to 3.5 millimetres, preferably from 1.5 millimetres to 3.5 millimetres, more preferably from 2.0 millimetres to 3.5 millimetres, even more preferably from 2.25 millimetres to 3.5 millimetres.

In other embodiments, an equivalent diameter of the core body is from 1.25 millimetres to 3.0 millimetres, preferably from 1.5 millimetres to 3.0 millimetres, more preferably from 2.0 millimetres to 3.0 millimetres, even more preferably from 2.25 millimetres to 3.0 millimetres.

In further embodiments, an equivalent diameter of the core body is from 1.25 millimetres to 2.5 millimetres, preferably from 1.5 millimetres to 2.5 millimetres, more preferably from 2.0 millimetres to 2.5 millimetres, even more preferably from 2.25 millimetres to 2.5 millimetres.

Aerosol-generating articles wherein an equivalent diameter of the core body is in the ranges described above can be manufactured efficiently as it is easy to combine the core body with the shell portion containing the aerosol-generating substrate to form the aerosolgenerating element. Further, core bodies having an equivalent diameter in the ranges described above may impart desirable structural firmness to the aerosol-generating element, which may facilitate the assembling of the various components of the article, such as for example when the aerosol-generating element and a downstream section of the article are brought into longitudinal alignment and attached to one another.

In some embodiments, the core body is air-impermeable. As used herein, the term “air- impermeable” is used to describe an entity which does not allow air to pass through it. An air- impermeable entity can also be described as air-impervious.

In more detail, a core body denoted as air-impermeable or air-impervious is such that airflow through the core body from an upstream end of the core body to a downstream end of the core body is prevented. Additionally, airflow through the core body in a direction transverse to the longitudinal axis is also prevented.

Thus, in embodiments wherein the core body is air-impermeable, all the air drawn into the aerosol-generating article at the upstream end of the aerosol-generating article is only allowed to flow around the core body and through the shell portion that contains the aerosolgenerating substrate. Accordingly, convective mass transfer within the shell portion is facilitated and, as a result, extraction of aerosol species from the aerosol-generating substrate and delivery of aerosol species towards the mouth end of the aerosol-generating article are particularly favoured.

In other embodiments, the core body is air-permeable, that is, the core body is configured such that air is allowed to pass through it. In other words, a core body denoted as air-permeable defines an airflow path such that airflow through the core body from an upstream end of the core body to a downstream end of the core body is enabled. Additionally, airflow through the core body in a direction transverse to the longitudinal axis may also possible.

Preferably, an RTD of the core body is greater than an overall RTD of the aerosolgenerating article. This means that airflow entering the aerosol-generating article at the upstream end encounters less resistance flowing through portions of the article other than the core body, such as for example flowing through the shell portion. In other words, the shell portion is more air pervious than the core portion, and so in general airflow entering the aerosol-generating article at the upstream end will preferentially proceed through the shell portion.

If the RTD differential between the core body and the remainder of the aerosolgenerating article is sufficiently large, airflow entering the aerosol-generating article at the upstream end may substantially bypass the core portion entirely. It will be appreciated that this is clearly the case if the core body is substantially air-impermeable.

For example, an RTD of the core body may be at least 110 percent of an RTD of the aerosol-generating article. Preferably, an RTD of the core body is at least 120 percent of an RTD of the aerosol-generating article. More preferably, an RTD of the core body is at least 125 percent of an RTD of the aerosol-generating article. Even more preferably, an RTD of the core body is at least 130 percent of an RTD of the aerosol-generating article.

An RTD of the core body may for example be up to 160 percent of an RTD of the aerosolgenerating article. Preferably, an RTD of the core body is less than or equal to 150 percent of an RTD of the aerosol-generating article. More preferably, an RTD of the core body is less than or equal to 145 percent of an RTD of the aerosol-generating article. Even more preferably, an RTD of the core body is less than or equal to 140 percent of an RTD of the aerosol-generating article.

In some embodiments, an RTD of the core body is from 110 percent to 160 percent of an RTD of the aerosol-generating article, preferably from 120 percent to 160 percent of an RTD of the aerosol-generating article, more preferably from 125 percent to 160 percent of an RTD of the aerosol-generating article, even more preferably from 130 percent to 160 percent of an RTD of the aerosol-generating article. In other embodiments, an RTD of the core body is from 110 percent to 150 percent of an RTD of the aerosol-generating article, preferably from 120 percent to 150 percent of an RTD of the aerosol-generating article, more preferably from 125 percent to 150 percent of an RTD of the aerosol-generating article, even more preferably from 130 percent to 150 percent of an RTD of the aerosol-generating article. In further embodiments, an RTD of the core body is from 110 percent to 145 percent of an RTD of the aerosol-generating article, preferably from 120 percent to 145 percent of an RTD of the aerosol-generating article, more preferably from 125 percent to 145 percent of an RTD of the aerosol-generating article, even more preferably from 130 percent to 145 percent of an RTD of the aerosol-generating article. In yet further embodiments, an RTD of the core body is from 110 percent to 140 percent of an RTD of the aerosol-generating article, preferably from 120 percent to 140 percent of an RTD of the aerosol-generating article, more preferably from 125 percent to 140 percent of an RTD of the aerosol-generating article, even more preferably from 130 percent to 140 percent of an RTD of the aerosol-generating article.

For example, this may be achieved by adjusting a cross-sectional porosity of the core body and the shell portion such that their respective RTD satisfy the proportionality relationships described above.

A resistance to draw measured across the core body by the CORESTA method No. 41 (June 2007) may be at least 150 millimetres Water Column (WC). Preferably, a resistance to draw measured across the core body by the CORESTA method No. 41 (June 2007) is at least 200 millimetres Water Column (WC). More preferably, a resistance to draw measured across the core body by the CORESTA method No. 41 (June 2007) is at least 300 millimetres Water Column (WC). In turn, a resistance to draw measured across the aerosol-generating article as a whole by the CORESTA method No. 41 (June 2007) is preferably at least 20 millimetres WC. More preferably, a resistance to draw measured across the aerosol-generating article as a whole by the CORESTA method No. 41 (June 2007) is at least 30 millimetres WC. Even more preferably, a resistance to draw measured across the aerosol-generating article as a whole by the CORESTA method No. 41 (June 2007) is at least 50 millimetres WC.

A resistance to draw measured across the aerosol-generating article as a whole by the CORESTA method No. 41 (June 2007) may be up to 120 millimetres WC. Preferably, a resistance to draw measured across the aerosol-generating article as a whole by the CORESTA method No. 41 (June 2007) is less than or equal to 110 millimetres WC. More preferably, a resistance to draw measured across the aerosol-generating article as a whole by the CORESTA method No. 41 (June 2007) is less than or equal to 100 millimetres WC. Even more preferably, a resistance to draw measured across the aerosol-generating article as a whole by the CORESTA method No. 41 (June 2007) is less than or equal to 90 millimetres WC.

In some embodiments, a resistance to draw measured across the aerosol-generating article as a whole by the CORESTA method No. 41 (June 2007) is from 20 millimetres WC to 120 millimetres WC, preferably from 30 to 120 millimetres EC, more preferably from 50 millimetres WC to 120 millimetres WC. In other embodiments, a resistance to draw measured across the aerosol-generating article as a whole by the CORESTA method No. 41 (June 2007) is from 20 millimetres WC to 110 millimetres WC, preferably from 30 to 110 millimetres EC, more preferably from 50 millimetres WC to 110 millimetres WC. In further embodiments, a resistance to draw measured across the aerosol-generating article as a whole by the CORESTA method No. 41 (June 2007) is from 20 millimetres WC to 100 millimetres WC, preferably from 30 to 100 millimetres EC, more preferably from 50 millimetres WC to 100 millimetres WC. In yet further embodiments, a resistance to draw measured across the aerosol-generating article as a whole by the CORESTA method No. 41 (June 2007) is from 20 millimetres WC to 90 millimetres WC, preferably from 30 to 90 millimetres EC, more preferably from 50 millimetres WC to 90 millimetres WC.

In embodiments where the core body is air-permeable, the aerosol-generating element may further comprise at least one air-impermeable peripheral layer circumscribing the core body, an outer surface of the peripheral layer facing an inner surface of the shell portion.

The peripheral layer extends at least over a side surface of the core body. Thus, the air-impermeable peripheral layer acts as a barrier between the core body and the shell portion, such that airflow through the peripheral layer is prevented. As such, air drawn into the aerosolgenerating article at the upstream end may flow into the core body, but not from the core body into the shell portion in a direction transversal to the longitudinal axis (for example, radially). Similarly, air drawn into the shell portion at the upstream end may not flow into the core body, but can only advance further downstream towards the mouth end of the aerosol-generating article.

This may be desirable as it enables two separate airflows to be established through the shell portion and the air-permeable core body, respectively. Each airflow is regulated by the RTD across the respective one of the shell portion and the air-permeable core body.

In some embodiments, the peripheral layer may substantially encapsulate the core body on all sides. Therefore, the peripheral layer may extend not only over a side surface of the core body, but also over upstream and downstream end surfaces of the core body. This may be beneficial in that the core body may be formed from a highly porous material, so that it does not substantially contribute to an overall weight of the article, whilst at the same time ensuring that a barrier is provided not only between the core body and the shell portion, but also at the ends of the core body. As a result, airflow through the core body may be entirely prevented even though the material forming the core body may in and of itself be highly air-permeable.

In general, characteristics of the material or materials used for forming the core body may have some impact on properties of the core body, such as its density, permeability, and so forth. For example, forming the core body from an inherently porous material may be a way of imparting a given porosity and permeability to the core body itself.

Provided that the material or materials from which the core body is formed is capable of withstanding the temperatures the aerosol-generating article reaches during use, a number of suitable materials will be known to the skilled person.

In particular, the core body may comprise one or more of cellulose acetate tow, cotton, ceramics, sintered metals, dense polymeric foams, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), glass, clay, iron oxide, alumina, titania, silica, silica-alumina, zirconia, ceria, zeolites, zirconium phosphate, and polymers capable of withstanding temperatures up to 250 degrees Celsius, preferably up to 300 degrees Celsius.

In some embodiments, the core body comprises one or more of cellulose acetate tow, cotton, ceramics, sintered metals, dense polymeric foams, and polymers capable of withstanding temperatures up to 250 degrees Celsius, preferably up to 300 degrees Celsius.

These materials are particularly suitable for forming a core body that, whilst being porous, has a relatively low air-permeability and can maintain its structure and integrity at high temperatures. Therefore, a core body formed of one these materials may be configured to enable limited airflow through the core body whilst effectively directing most of the air drawn into the aerosol-generating article to flow through the shell portion.

In other embodiments, the core body comprises one or more of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), glass, clay, iron oxide, alumina, titania, silica, silica- alumina, zirconia, ceria, zeolites, zirconium phosphate. These materials are particularly suitable for forming an air-impermeable core body, such that airflow through the aerosol-generating element is only enabled through the shell portion.

The core body may also comprise a substantially air impervious material that has been processed and formed into a permeable structure. Thus, a core body may advantageously be manufactured that, whilst being formed of a material that is not inherently air permeable, has a predetermined permeability and so enables some airflow.

In certain embodiments, the core body may comprise a further aerosol-forming component. The term “further aerosol-forming component” is used herein to denote a component that is different and distinct from the aerosol-generating substrate contained in the shell portion, and which is capable of releasing upon heating one or more further volatile compounds that can be delivered to the consumer as part of an inhalable aerosol.

In general, the further aerosol-forming component may be adapted to release one or more further volatile compounds only when heated to a temperature at least as high as the one at which the aerosol-generating substrate contained in the shell portion is capable of releasing volatile compounds. Alternatively, the further aerosol-forming component may be adapted to release one or more further volatile compounds at temperatures lower than the one at which the aerosol-generating substrate contained in the shell portion needs to be heated to release aerosol species. As the permeability and RTD of the core body will generally differ from the permeability and RTD of the shell portion, and since the core body and the shell portion will typically reach different temperatures when the aerosol-generating article is heated in an aerosol-generating device during use, timing and dynamics of release of volatile compounds from the aerosol-generating substrate contained in the shell portion and from the further aerosol-forming component contained in the core body will also generally differ.

Thus, the further volatile compounds may be released and delivered to the consumer along with the compounds released upon heating the aerosol-generating substrate contained in the shell portion or released and delivered to the consumer at a different time.

The core body may, for example, contain 0.1 percent by weight of the further aerosolforming component based on the total weight of the core body. Preferably, the core body contains 0.25 percent by weight of the further aerosol-forming component based on the total weight of the core body. More preferably, the core body contains 0.5 percent by weight of the further aerosol-forming component based on the total weight of the core body. Even more preferably, the core body contains 1 percent by weight of the further aerosol-forming component based on the total weight of the core body.

The core body may, for example, contain up to 5 percent by weight of the further aerosolforming component based on the total weight of the core body. Preferably, the core body contains less than or equal to 3 percent by weight of the further aerosol-forming component based on the total weight of the core body. More preferably, the core body contains less than or equal to 2 percent by weight of the further aerosol-forming component based on the total weight of the core body.

The further aerosol-forming component may comprise a flavourant. This has the benefit that a further desired flavour may be provided upon heating of the aerosol-generating element.

Suitable flavourants for inclusion in the core body of an aerosol-generating article in accordance with the present invention would be well known to the skilled person. The flavourant may include one or more natural flavourants, one or more synthetic flavourants, or a combination of natural and synthetic flavourants. Suitable flavourants include, but are not limited to, natural or synthetic menthol, mint flavour such as peppermint flavour or spearmint flavour, coffee flavour, spice flavours (such as cinnamon, clove and ginger), cocoa flavour, vanilla flavour, fruit flavours, chocolate flavour, liquorice flavour, citrus flavour, gamma octalactone, vanillin, ethyl vanillin, breath freshener flavours, methyl salicylate, linalool, bergamot oil, geranium oil, lemon oil, ginger oil, and tobacco flavour, tea flavour, wine flavour, berry flavour, eucalyptus, geranium, eugenol, agave, juniper, anethole and linalool.

The further aerosol-forming component may comprise nicotine. In particular, the further aerosol-forming component may comprise isolated nicotine and nicotine salts derived from tobacco. Including a further aerosol-forming component comprising nicotine in the core body of an aerosol-generating article in accordance with the present invention - especially if combined with use of a tobacco-containing aerosol-generating substrate in the shell portion - may provide a way of further controlling and fine-tuning nicotine delivery to the consumer.

The further aerosol-forming component may comprise an active compound other than nicotine. The term “active compound” is used herein to denote a compound capable of exerting a direct physiological effect on a consumer. For example, the further aerosol-forming component may comprise anatabine, another alkaloid compound present in tobacco, green tomatoes, ripe red peppers, and so forth.

The further aerosol-forming component may be provided on an outer surface of the core body. This may be desirable as the further aerosol-forming component may be heated substantially to the same temperature reached by the aerosol-generating substrate located most internally within the shell portion, and this may facilitate simultaneous or quasi- simultaneous release of volatile compounds from both aerosol-generating substrate and further aerosol-forming component.

In embodiments where an air-impermeable layer is provided that circumscribes the core body and establishes a barrier between the core body and the shell portion, the further aerosol-forming component may also be provided on an outer surface of the air-impermeable layer. The further aerosol-forming component may be provided internally within the core body. For example, if the core body is formed of a porous material, the further aerosol-forming component may be provided within internal pores of the core body.

The further aerosol-forming component may also be provided in encapsulated form, be it on an outer surface of the core body or within the core body, for example as a volatile compound contained in one or more microcapsules. Thus, release of the encapsulated volatile during use may be selectively activated by an action of the consumer. As an alternative, release of the encapsulated volatile during use may be achieved when a predetermined temperature is reached within the aerosol-generating element that causes thermal degradation of the material encapsulating the volatile compound.

An aerosol-generating article according to the present invention may comprise one or more additional elements provided downstream of the aerosol-generating element and in axial alignment with the aerosol-generating element. The one or more additional elements provided downstream of the aerosol-generating element and in axial alignment with the aerosolgenerating substrate form a downstream section of the aerosol-generating article.

For example, the aerosol-generating article may comprise a mouthpiece element at the downstream end or mouth end or proximal end of the aerosol-generating article. The mouthpiece element may comprise a single plug element comprising filtration material. As an alternative, the mouthpiece element may comprise two or more components, such as for example a plug element comprising filtration material paired with a hollow tubular element arranged downstream of the plug element and defining a recess at a mouth end of the aerosolgenerating article.

The mouthpiece element may have a low particulate phase filtration efficiency or even substantially no particulate phase filtration efficiency. Whilst capable of preventing substrate material from the aerosol-generating element potentially reaching the mouth of the consumer during use, a mouthpiece element having low particulate phase filtration efficiency has a reduced impact on delivery of aerosol species to the consumer. This is especially advantageous in an aerosol-generating article wherein the aerosol-generating substrate is heated as opposed to being combusted.

A length of the mouthpiece element may be at least about 3 millimetres, or at least about 5 millimetres.

The length of the mouthpiece element may be less than or equal to about 11 millimetres, or less than or equal to about 9 millimetres.

The length of the mouthpiece element may be between about 3 millimetres and about 11 millimetres, or between about 3 millimetres and about 9 millimetres.

The length of the mouthpiece element may be between about 5 millimetres and about 11 millimetres, or between about 5 millimetres and about 9 millimetres. For example, the length of the mouthpiece element may be about 7 millimetres.

The length of the mouthpiece element may be selected based on a desired total length of the aerosol-generating article.

The mouthpiece element may be circumscribed by a plug wrap.

The mouthpiece element may be unventilated such that air does not enter the aerosolgenerating article along the mouthpiece element.

The mouthpiece element may be connected to one or more adjacent components of the aerosol-generating article by means of a tipping wrapper.

The downstream section may comprise a support element provided immediately downstream of the aerosol-generating element, preferably adjacent to the aerosol-generating element. One such support element is adapted to impart structural strength to the aerosolgenerating article.

The downstream section may comprise an aerosol-cooling element adapted to facilitate cooling of the aerosol generated during use of the aerosol-generating article prior to reaching the downstream end of the aerosol-generating article.

The aerosol-cooling element preferably has a low resistance to draw. That is, the aerosol-cooling element preferably offers a low resistance to the passage of air through the aerosol-generating article. Preferably, the aerosol-cooling element does not substantially affect the resistance to draw of the aerosol-generating article.

The aerosol-cooling element may comprise a plurality of longitudinally extending channels. The plurality of longitudinally extending channels may be defined by a sheet of material that has been one or more of crimped, pleated, gathered and folded to form the channels. The plurality of longitudinally extending channels may be defined by a single sheet that has been one or more of crimped, pleated, gathered and folded to form multiple channels. Alternatively, the plurality of longitudinally extending channels may be defined by multiple sheets that have been one or more of crimped, pleated, gathered and folded to form multiple channels.

For example, the aerosol-cooling element may be formed from a gathered sheet of paper material having a specific surface area of between approximately 10 square millimetres per milligram and approximately 100 square millimetres per milligram. In some embodiments, the aerosol-cooling element may be formed from a gathered sheet of PLA.

At least one of the support element and the aerosol-cooling element may be in the form of a hollow tubular element. In some embodiments, both the support element and the aerosolcooling element are in the form of hollow tubular elements, which may differ in length, internal diameter or both.

In an aerosol-generating article in accordance with the present invention, such a hollow tubular element provides an unrestricted flow channel. This means that the hollow tubular element provides a negligible level of RTD. As used herein with reference to the invention, the term “negligible level of RTD” is used to describe an RTD of less than 1 mm H2O per 10 millimetres of length of the hollow tubular substrate element, less than 0.4 mm H2O per 10 millimetres of length of the hollow tubular substrate element, or less than 0.1 mm H2O per 10 millimetres of length of the hollow tubular substrate element. The flow channel should therefore be free from any components that would obstruct the flow of air in a longitudinal direction. Preferably, the flow channel is substantially empty.

The hollow tubular element may have a total length of at least about 10 millimetres, at least about 12 millimetres, or at least about 15 millimetres.

The hollow tubular element may have a total length of less than or equal to about 30 millimetres, less than or equal to about 25 millimetres, or less than or equal to about 23 millimetres.

The hollow tubular element may have a total length of between about 10 millimetres and about 30 millimetres, between about 10 millimetres and about 25 millimetres, or between about 10 millimetres and about 23 millimetres. The hollow tubular element may have a total length of between about 12 millimetres and about 30 millimetres, between about 12 millimetres and about 25 millimetres, or between about 12 millimetres and about 23 millimetres. The hollow tubular element may have a total length of between about 12 millimetres and about 30 millimetres, between about 12 millimetres and about 25 millimetres, or between about 12 millimetres and about 23 millimetres.

The total length of the hollow tubular element may be selected based on a desired total length of the aerosol-generating article.

In some embodiments, a ventilation zone may be provided at a location downstream of the aerosol-generating element.

For example, a satisfactory cooling of the stream of aerosol generated upon heating the aerosol-generating substrate and drawn through a hollow tubular element as described above may be achieved by providing a ventilation zone at a location along the hollow tubular element itself. Without wishing to be bound by theory, the temperature drop caused by the admission of cooler, external air into the aerosol-generating article downstream of the aerosol-generating element via the ventilation zone may have an advantageous effect on the nucleation and growth of aerosol particles.

The ventilation zone may comprise a plurality of perforations, for example provided through a tubular wall of the hollow tubular element. The ventilation zone may comprise at least one circumferential row of perforations. The ventilation zone may comprise two circumferential rows of perforations. For example, the perforations may be formed online during manufacturing of the aerosol-generating article. Each circumferential row of perforations may comprise from 8 to 30 perforations. In some embodiments, the aerosol-generating article comprises an upstream section located upstream of the aerosol-generating element. The upstream section is preferably located immediately upstream of the aerosol-generating element. The upstream section preferably extends from an upstream end of the aerosol-generating article to an upstream end of the aerosol-generating element. The upstream section preferably comprises an upstream element located immediately upstream of the aerosol-generating element.

Where the aerosol-generating substrate comprises shredded tobacco, such as tobacco cut filler, the upstream section or element thereof may additionally help to prevent the loss of loose particles of tobacco from the upstream end of the article.

The upstream section, or upstream element thereof, may also additionally provide a degree of protection to the aerosol-generating substrate during storage, as it covers at least to some extent the upstream end of the aerosol-generating element, which may otherwise be exposed. For aerosol-generating articles that are intended to be inserted into a cavity in an aerosol-generating device such that the aerosol-generating substrate can be externally heated within the cavity, the upstream section, or upstream element thereof, may advantageously facilitate the insertion of the upstream end of the article into the cavity.

An upstream element of the upstream section may be made of any material suitable for use in an aerosol-generating article. The upstream element may, for example, be made of a same material as used for one of the other components of the aerosol-generating article, such as the mouthpiece, the aerosol-cooling element or the support element, the geometry and function of which have been described above. Suitable materials for forming the upstream element include filter materials, ceramic, polymer material, cellulose acetate, cardboard, zeolite or aerosol-generating substrate.

In preferred embodiments, the upstream element may comprise a plug element comprising a filtration material. For example, the upstream element may be formed of the same cellulosic filtration material as the mouthpiece element described above.

Preferably, the upstream section or an upstream element has a length of between about 2 millimetres and about 8 millimetres, more preferably between about 3 millimetres and about 7 millimetres, more preferably between about 4 millimetres and about 6 millimetres. In a particularly preferred embodiment, the upstream section or an upstream element has a length of about 5 millimetres. The length of the upstream section or an upstream element can advantageously be varied in order to provide the desired total length of the aerosol-generating article.

The upstream section is preferably circumscribed by a wrapper, such as a plug wrap. The wrapper circumscribing the upstream section may be a stiff plug wrap, for example, a plug wrap having a basis weight of at least about 80 grams per square metre (gsm), or at least about 100 gsm, or at least about 110 gsm. This provides increased structural rigidity to the upstream section.

The upstream section is preferably connected to the aerosol-generating element and optionally at least a part of the downstream section by means of an outer wrapper.

The aerosol-generating article preferably has an overall length of from 40 millimetres to 80 millimetres, or from 40 millimetres to about 70 millimetres, or from 40 millimetres to about 60 millimetres, or from 45 millimetres to about 80 millimetres, or from about 45 millimetres to about 70 millimetres, or from 45 millimetres to 60 millimetres, or from 50 millimetres to 80 millimetres, or from 50 millimetres to about 70 millimetres or from about 50 millimetres to about 60 millimetres. In an exemplary embodiment, an overall length of the aerosol-generating article is about 45 millimetres.

Preferably, the aerosol-generating article has a substantially circular cross-section.

The aerosol-generating article preferably has an external diameter of from about 5 millimetres to about 12 millimetres, or from about 6 millimetres to about 12 millimetres, or from about 7 millimetres to about 12 millimetres, or from about 5 millimetres to about 10 millimetres, or from about 6 millimetres to about 10 millimetres, or from about 7 millimetres to about 10 millimetres, or from about 5 millimetres to about 8 millimetres, or from about 6 millimetres to about 8 millimetres, or from about 7 millimetres to about 8 millimetres. In other embodiments, the aerosol-generating article has an external diameter of less than 7 millimetres.

An aerosol-generating element in accordance with the present disclosure may be paired with a suitable aerosol-generating device to provide an aerosol-generating system.

As described briefly above, an aerosol-generating system for producing an inhalable aerosol may comprise an aerosol-generating article in line with the foregoing description and an aerosol-generating device comprising a heating arrangement configured to heat at least a portion of the aerosol-generating substrate to generate an aerosol.

For example, the aerosol-generating device may comprise a heating chamber adapted to at least partly receive the aerosol-generating article to supply heat to the aerosol-generating element. In particular, the aerosol-generating element may comprise one or more heating element configured to be positioned externally of the aerosol-generating element when the aerosol-generating article is received within the heating chamber.

The invention is defined in the claims. However, below there is provided a non- exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

Examples

Example Ex1 : An aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article comprising: a longitudinally extending aerosol- generating element; and a downstream section at a location downstream of the aerosolgenerating element; wherein the aerosol-generating element comprises a core body and an air-permeable shell portion circumscribing the core body, the shell portion comprising a primary aerosol-generating substrate and defining an airflow path through the shell portion; wherein the core body is substantially free of the primary aerosol-generating substrate; wherein a cross-sectional area of the core body is at least 3 percent of an overall cross- sectional area of the aerosol-generating element.

Example Ex2: An aerosol-generating article according to example Ex1 , wherein a cross- sectional area of the core body is at least 5 percent of an overall cross-sectional area of the aerosol-generating section.

Example Ex3: An aerosol-generating article according to example Ex1 or example Ex2, wherein a cross-sectional area of the core body is at least 10 percent of an overall cross- sectional area of the aerosol-generating section.

Example Ex4: An aerosol-generating article according to any one of the preceding examples, wherein a cross-sectional area of the core body is at least 12 percent of an overall cross-sectional area of the aerosol-generating section.

Example Ex5: An aerosol-generating article according to any one of the preceding examples, wherein a cross-sectional area of the core body is less than or equal to 30 percent of an overall cross-sectional area of the aerosol-generating section.

Example Ex6: An aerosol-generating article according to any one of the preceding examples, wherein a cross-sectional area of the core body is less than or equal to 25 percent of an overall cross-sectional area of the aerosol-generating section.

Example Ex7: An aerosol-generating article according to any one of the preceding examples, wherein a cross-sectional area of the core body is less than or equal to 20 percent of an overall cross-sectional area of the aerosol-generating section.

Example Ex8: An aerosol-generating article according to any one of the preceding examples, wherein an equivalent diameter of the core body is at least 1.3 millimetres.

Example Ex9: An aerosol-generating article according to any one of the preceding examples, wherein an equivalent diameter of the core body is at least 1.5 millimetres.

Example Ex10: An aerosol-generating article according to any one of the preceding examples, wherein an equivalent diameter of the core body is at least 2.0 millimetres.

Example Ex11 : An aerosol-generating article according to any one of the preceding examples, wherein an equivalent diameter of the core body is less than or equal to 3.0 millimetres.

Example Ex12: An aerosol-generating article according to any one of the preceding examples, wherein an equivalent diameter of the core body is less than or equal to 2.7 millimetres. Example Ex13: An aerosol-generating article according to any one of the preceding examples, wherein an equivalent diameter of the core body is less than or equal to 2.5 millimetres.

Example Ex14: An aerosol-generating article according to any one of the preceding examples, wherein a resistance to draw (RTD) of the core body is at least 110 percent of an RTD of the aerosol-generating article.

Example Ex15: An aerosol-generating article according to any one of the preceding examples, wherein a resistance to draw (RTD) of the core body is at least 120 percent of an RTD of the aerosol-generating article.

Example Ex16: An aerosol-generating article according to any one of the preceding examples, wherein a resistance to draw (RTD) of the core body is at least 130 percent of an RTD of the aerosol-generating article.

Example Ex17: An aerosol-generating article according to any one of the preceding examples, wherein a resistance to draw (RTD) of the core body is less than or equal to 160 percent of an RTD of the aerosol-generating article.

Example Ex18: An aerosol-generating article according to any one of the preceding examples, wherein a resistance to draw (RTD) of the core body is less than or equal to 150 percent of an RTD of the aerosol-generating article.

Example Ex19: An aerosol-generating article according to any one of the preceding examples, wherein a resistance to draw (RTD) of the core body is less than or equal to 140 percent of an RTD of the aerosol-generating article.

Example Ex20: An aerosol-generating article according to any one of the preceding examples, wherein a resistance to draw (RTD) measured across the aerosol-generating article by the CORESTA method No. 41 (June 2007) is at least 20 millimetres WC.

Example Ex21 : An aerosol-generating article according to any one of the preceding examples, wherein a resistance to draw measured across the aerosol-generating article by the CORESTA method No. 41 (June 2007) is less than or equal to 110 millimetres WC.

Example Ex22: An aerosol-generating article according to any one of the preceding examples, wherein the aerosol-generating element comprises at least one air-impervious peripheral layer circumscribing the core body, an outer surface of the peripheral layer facing an inner surface of the shell portion.

Example Ex23: An aerosol-generating article according to example Ex22, wherein the at least one peripheral layer is applied onto the core body by one or more of spray-coating, vapour deposition, sputtering, dipping, brushing, gluing, electrostatic deposition

Example Ex24: An aerosol-generating article according to any one of examples Ex1 to Ex23, wherein the core body comprises one or more of cellulose acetate tow, cotton, ceramics, sintered metals, dense polymeric foams, and polymers capable of withstanding temperatures up to 250 degrees Celsius, preferably up to 300 degrees Celsius.

Example Ex25: An aerosol-generating article according to any one of examples Ex1 to Ex23, wherein the core body comprises one or more of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), glass, clay, iron oxide, alumina, titania, silica, silica-alumina, zirconia, ceria, zeolites, zirconium phosphate.

Example Ex26: An aerosol-generating article according to any one of examples Ex1 to Ex23, wherein the core body is made of a substantially air-impervious material.

Example Ex27: An aerosol-generating article according to any one of the preceding examples, wherein the core body comprises a further aerosol-forming component.

Example Ex28: An aerosol-generating article according to example Ex27, wherein the core body contains 0.1 percent by weight of the further aerosol-forming component based on the total weight of the core body.

Example Ex29: An aerosol-generating article according to example Ex27 or example Ex28, wherein the core body contains 1 percent by weight of the further aerosol-forming component based on the total weight of the core body.

Example Ex30: An aerosol-generating article according to any one of examples Ex27 to Ex29, wherein the core body contains less than or equal to 5 percent by weight of the further aerosol-forming component based on the total weight of the core body.

Example Ex31 : An aerosol-generating article according to any one of examples Ex27 to Ex30, wherein the core body contains less than or equal to 2 percent by weight of the further aerosol-forming component based on the total weight of the core body.

Example Ex32: An aerosol-generating article according to any one of examples Ex27 to Ex31 , wherein the further aerosol-forming component comprises a flavourant.

Example Ex33: An aerosol-generating article according to any one of examples Ex27 to Ex31 , wherein the further aerosol-forming component comprises nicotine or another active compound.

Example Ex34: An aerosol-generating article according to any one of examples Ex27 to Ex33, wherein the further aerosol-forming component is provided on an outer surface of the core body.

Example Ex35: An aerosol-generating article according to any one of examples Ex27 to Ex33, wherein the core body is air-permeable and the further aerosol-forming component is provided internally within the core body.

Example Ex36: An aerosol-generating article according to any one of the preceding examples, wherein the downstream section comprises a hollow tubular element, the hollow tubular element defining a cavity in direct fluid communication with the shell portion. Example Ex37: An aerosol-generating article according to any one of the preceding examples, wherein the downstream section comprises a mouthpiece element at the downstream end of the aerosol-generating article.

Example Ex38: An aerosol-generating article according to any one of the preceding examples, further comprising an upstream section at a location upstream of the aerosolgenerating element.

Example Ex39: An aerosol-generating article according to any one of the preceding examples, wherein the aerosol-generating substrate comprises tobacco.

Example Ex40: An aerosol-generating article according to example Ex39, wherein the aerosol-generating substrate comprises a homogenised tobacco material comprising an aerosol former.

Example Ex41 : An aerosol-generating system for producing an inhalable aerosol, the system comprising: an aerosol-generating article according to any one of examples Ex1 to Ex40, and an aerosol-generating device comprising a heating arrangement configured to heat at least a portion of the aerosol-generating substrate to generate an aerosol.

Example Ex42: An aerosol-generating system according to example Ex41 , wherein the heating arrangement comprises a heating chamber configured to at least partly receive the aerosol-generating article and one or more heating element provided along or around a peripheral wall of the heating chamber and configured to supply heat to the aerosol-generating substrate.

Examples will now be further described with reference to the figures in which:

Figure 1 shows a schematic sectional side view of an aerosol-generating article according to the present invention;

Figure 2 shows a cross sectional view of the aerosol-generating element of the aerosolgenerating article of Figure 1 taken along the plane A-A in Figure 1 ;

Figure 3 shows a schematic sectional side view of another aerosol-generating article according to the present invention;

Figure 4 shows a cross sectional view of the aerosol-generating element of the aerosolgenerating article of Figure 3 article taken along the plane B-B in Figure 3; and

Figure 5 shows a sectional side view of an aerosol-generating system according to the present invention.

An aerosol-generating article 100 in accordance with the present invention is illustrated schematically in Figure 1.

The aerosol-generating article 100 shown in Figure 1 extends from an upstream end 101 to a downstream end 102. The aerosol-generating article 100 comprises an aerosol-generating element 103 at the upstream end 101 of the aerosol-generating article 100.

The aerosol-generating element 103 extends longitudinally from the upstream end 101 of the aerosol-generating article 100 and an intermediate point 104.

The aerosol-generating element 103 comprises a core body 105 and a shell portion 106 circumscribing the core body 105.

The shell portion 106 is substantially tubular in shape, comprises an aerosolgenerating substrate and defines an airflow path through the shell portion 106. Thus, gaseous flow is enabled from the upstream end 101 to the intermediate point 104 through the aerosolgenerating substrate. In more detail, the aerosol-generating substrate is in the form of a sheet of homogenised tobacco material. Use of a primary aerosol-generating substrate in sheet form, such as homogenised tobacco material, has the advantage that the sheet can be conveniently gathered our wound around the core portion. The aerosol-generating substrate may be circumscribed by a wrapper (not shown).

An outer diameter of the shell portion 106 is 7 millimetres. This can also be described as the equivalent outer diameter (DEQ) of the aerosol-generating element 103 (see Figure 2).

The core body 105 comprises a cylindrical insert made of a cellulosic material, and contains none of the aerosol-generating substrate contained in the shell portion 106.

Suitable cellulosic materials for forming the core body 105 will be known to the skilled person. In an example, the cylindrical insert may be formed of a fibrous material comprising regenerated cellulose fibres, such as one or more of viscose fibres, modal fibres, Lyocell fibres and viscose rayon fibres, and wherein the additive coating is applied to the plurality of regenerated cellulose fibres. In another example, the cylindrical insert may be formed of a fibrous material comprising natural fibres, such as one or more of flax fibres, hemp fibres, jute fibres, kenaf fibres, ramie fibres, abaca fibres, phormium fibres, sisal fibres, coir fibres, cotton fibres, and kapok fibres, and wherein the additive coating is applied to the plurality of natural fibres. In a further example, the cylindrical insert may be formed of a paper material.

An outer diameter of the core body is substantially equal to an internal diameter of the shell portion, and measures 3 millimetres. This can also be described as the equivalent outer diameter (dEo) of the core body 105.

The aerosol-generating article 100 further comprises a downstream section located immediately downstream of the aerosol-generating element 103.

The downstream section comprises a hollow tubular element 107 and a mouthpiece element 108 downstream of the hollow tubular element 107.

The hollow tubular element 107 defines a hollow section of the aerosol-generating article 100. The hollow tubular element 107 does not substantially contribute to the overall RTD of the aerosol-generating article 100. In more detail, an RTD of the hollow tubular element 107 is about 0 mm H2O.

The hollow tubular element 107 is provided in the form of a hollow cylindrical tube made of cardboard. The hollow tubular element 107 defines an internal cavity 109 that extends all the way from an upstream end of the hollow tubular element 107 to a downstream end of the hollow tubular element 107. The internal cavity 109 is substantially empty, and so substantially unrestricted airflow is enabled along the internal cavity 109. Fluid communication is therefore established between the shell portion 106 and the cavity 109.

The aerosol-generating article 100 comprises a ventilation zone 110 provided at a location along the hollow tubular element 107. The ventilation zone 110 comprises a circumferential row of openings or perforations circumscribing the hollow tubular element 107. The perforations of the ventilation zone 110 extend through the wall of the hollow tubular element 107, in order to allow fluid ingress into the internal cavity 109 from the exterior of the article 100. A ventilation level of the aerosol-generating article 100 is about 40 percent.

The mouthpiece element 108 extends from a downstream end of the hollow tubular element 107 to the downstream end 102 of the aerosol-generating article 100. The mouthpiece element 108 comprises a low-density filter segment.

The aerosol-generating article 100 comprises a wrapper 111 circumscribing the aerosol-generating element 103, the hollow tubular element 107, and the mouthpiece element 108. The ventilation zone 110 may also comprise a circumferential row of perforations provided through the wrapper 111.

The aerosol-generating article 100 has an overall length of about 45 millimetres and an external diameter of about 7.2 millimetres.

Figures 3 and 4 illustrate another example of aerosol-generating article in accordance with the present invention. The aerosol-generating article 200 of Figures 3 and 4 will only be described insofar as it differs from the previously described aerosol-generating article 100 of Figures 1 and 2.

The aerosol-generating article 200 further comprises an air-impervious peripheral layer 112 circumscribing the core body 105, an outer surface of the peripheral layer 112 facing an inner surface of the shell portion 106.

The peripheral layer 112 is applied onto the core body 105 by one or more of spraycoating, vapour deposition, sputtering, dipping, brushing, gluing, electrostatic deposition.

Thus, the assembly formed of core body 105 and peripheral layer 112 has an augmented equivalent diameter adEQ which is substantially equal to an internal equivalent diameter of the shell portion 106.

Figure 5 illustrates an aerosol-generating system 200 according to the present invention. The first aerosol-generating system 200 comprises the aerosol-generating article 100 of Figure 1 , and a first aerosol-generating device 250. The aerosol-generating device 250 comprises a housing (or body) 201 , extending between a downstream end and an upstream end. The housing 201 defines a heating chamber 202 for receiving an aerosol-generating article 100. The heating chamber 202 is defined by a closed, upstream end and an open, downstream end. The downstream end of the heating chamber 202 is located at the downstream end of the aerosol-generating device 250. The aerosol-generating article 100 is configured to be received through the open, downstream end of the heating chamber 202 and is configured to abut a closed, upstream end of the heating chamber 202, when the aerosolgenerating article 100 is fully received in the heating chamber 202.

The aerosol-generating device 250 further comprises a heater arrangement 203 and a power source 204 for supplying power to the heater arrangement 203. A controller (not shown) is also provided to control such supply of power to the heater arrangement 203. The heater arrangement 203 is configured to controllably heat the aerosol-generating article 100 during use, when the aerosol-generating article 100 is fully received within the heating chamber 202.

The heater arrangement 203 extends from an upstream end to a downstream end defining a heating zone. The heater arrangement 203 is substantially the same length as the aerosol-generating element 103 such that when the aerosol-generating article 100 is fully received within the heating chamber 202, the entire length of the aerosol-generating element 103 is received within the heating zone to provide optimal heating of the aerosol-generating substrate reservoir 103. The heater arrangement 203 comprises a resistive heating element.

The ventilation zone 108 is arranged to be exposed when the aerosol-generating article 100 is fully received within the heating chamber 202.

In use, the aerosol-generating article 100 is fully received within the heating chamber 202 of the aerosol-generating device 250. The heater arrangement 203 is activated by the controller and the resistive heating element generates heat which is transferred directly to the aerosol-generating substrate reservoir 103 which is disposed within the heating zone. This generates an aerosol in the aerosol-generating element 103. When a pressure drop is applied to the downstream end 102 of the aerosol-generating article 100, air is drawn into the heating chamber 202 and into the aerosol-generating element 103. The aerosols generated in the aerosol-generating element 103 is entrained in the airflow which then passes through the downstream section before leaving through the downstream end 102 of the aerosolgenerating article 100.

In particular, given the difference in RTD between the shell portion 106 and the core body 105, the air drawn into the heating cavity is directed to flow primarily through the shell portion 106. For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ± 5% of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

Claims

1. An aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article comprising: a longitudinally extending aerosol-generating element; and a downstream section at a location downstream of the aerosol-generating element; wherein the aerosol-generating element comprises a core body and an air-permeable shell portion circumscribing the core body, the shell portion comprising an aerosol-generating substrate and defining an airflow path through the shell portion; wherein the core body comprises one or more of cellulose acetate tow, cotton, ceramics, dense polymeric foams, and polymers capable of withstanding temperatures up to 250 degrees Celsius or one or more of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), glass, clay, iron oxide, alumina, titania, silica, silica-alumina, zirconia, ceria, zeolites, zirconium phosphate and is substantially free of the aerosol-generating substrate; wherein a cross-sectional area of the core body is at least 3 percent of an overall cross- sectional area of the aerosol-generating element.

2. An aerosol-generating article according to claim 1 , wherein a cross-sectional area of the core body is at least 5 percent of an overall cross-sectional area of the aerosol-generating section.

3. An aerosol-generating article according to any one of the preceding claims, wherein a cross-sectional area of the core body is less than or equal to 30 percent of an overall cross- sectional area of the aerosol-generating section.

4. An aerosol-generating article according to any one of the preceding claims, wherein an equivalent diameter of the core body is at least 1.3 millimetres.

5. An aerosol-generating article according to any one of the preceding claims, wherein an equivalent diameter of the core body is less than or equal to 3.0 millimetres.

6. An aerosol-generating article according to any one of the preceding claims, wherein a resistance to draw (RTD) of the core body is at least 110 percent of an RTD of the aerosolgenerating article.

7. An aerosol-generating article according to any one of the preceding claims, wherein a resistance to draw (RTD) of the core body is less than or equal to 160 percent of an RTD of the aerosol-generating article.

8. An aerosol-generating article according to any one of the preceding claims, wherein the aerosol-generating element comprises at least one air-impervious peripheral layer circumscribing the core body, an outer surface of the peripheral layer facing an inner surface of the shell portion.

9. An aerosol-generating article according to claim 8, wherein the at least one peripheral layer is applied onto the core body by one or more of spray-coating, vapour deposition, sputtering, dipping, brushing, gluing, electrostatic deposition

10. An aerosol-generating article according to any one of claims 1 to 9, wherein the core body is made of a substantially air-impervious material.

11. An aerosol-generating article according to any one of the preceding claims, wherein the core body comprises a further aerosol-forming component.

12. An aerosol-generating system for producing an inhalable aerosol, the system comprising: an aerosol-generating article according to any one of claims 1 to 11 , and an aerosol-generating device comprising a heating arrangement configured to heat at least a portion of the aerosol-generating substrate to generate an aerosol.

13. An aerosol-generating system according to claim 12, wherein the heating arrangement comprises a heating chamber configured to at least partly receive the aerosol-generating article and one or more heating element provided along or around a peripheral wall of the heating chamber and configured to supply heat to the aerosol-generating substrate.