WO2024200700A1

WO2024200700A1 - Aerosol-generating article with an obstruction element

Info

Publication number: WO2024200700A1
Application number: PCT/EP2024/058569
Authority: WO
Inventors: Matteo Bologna
Original assignee: Philip Morris Products SA
Current assignee: Philip Morris Products SA
Priority date: 2023-03-31
Filing date: 2024-03-28
Publication date: 2024-10-03
Anticipated expiration: 2025-09-30
Also published as: CN120916654A; KR20250162914A

Abstract

An aerosol-generating article (100) comprising: an aerosol-generating substrate (10); an upstream element (20) located upstream of the aerosol-generating substrate (10), the upstream element (20) comprising a longitudinal airflow channel (24) and an obstruction element (26) for obstructing the longitudinal airflow channel (24), wherein the upstream element (20) is configured to change state upon heating during use of the aerosol-generating article (10) from: an initial state, in which the longitudinal airflow channel (24) is obstructed by the obstruction element (26) to substantially prevent airflow through the longitudinal airflow channel (24), to a final state, in which the longitudinal airflow channel (24) is at least partially open to allow airflow through the longitudinal airflow channel (24), wherein the upstream element (20) has a lower resistance to draw in the final state than in the initial state.

Description

AEROSOL-GENERATING ARTICLE WITH AN OBSTRUCTION ELEMENT

The present disclosure relates to an aerosol-generating article comprising an aerosolgenerating substrate for generating an inhalable aerosol upon heating. The present disclosure also relates to an aerosol-generating system comprising the aerosol-generating article and an aerosol-generating device configured to heat the aerosol-generating substrate of the aerosolgenerating article.

Aerosol-generating articles in which an aerosol-generating substrate comprising aerosol-generating material, such as a tobacco-containing material, is heated rather than combusted are known in the art. An aim of such ‘heated’ aerosol-generating articles is to reduce known harmful smoke constituents of the type produced by the combustion and pyrolytic degradation of tobacco in conventional cigarettes.

Typically, in heated aerosol-generating articles an aerosol is generated by the transfer of heat from a heat source to a physically separate aerosol-generating substrate. In use, volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source to the aerosol-generating substrate and are 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 user.

One known type of heated aerosol-generating article, commonly referred to as a heat- not-burn tobacco product or heated tobacco product, comprises a solid aerosol-generating substrate comprising tobacco material, which is heated to produce an inhalable aerosol.

A number of handheld aerosol-generating devices configured to heat aerosolgenerating substrates of heated aerosol-generating articles are known in the art. These include electrically-operated aerosol-generating devices in which an aerosol is generated by the transfer of heat from one or more electrical heating elements of the aerosol-generating device to the aerosol-generating substrate of the heated aerosol-generating article. Known handheld electrically operated aerosol-generating devices typically comprise a battery, control electronics and one or more electrical heating elements for heating the aerosol-generating substrate of a heated aerosol-generating article designed specifically for use with the aerosolgenerating device.

Some known electrically heated aerosol-generating devices comprise an internal heating element that is configured to be inserted into the aerosol-generating substrate of a heated aerosol-generating article. For example, WO 2013/098410 A2 discloses an aerosolgenerating system comprising an aerosol-generating article and an electrically-operated aerosol-generating device comprising a heating element in the form of a blade that is inserted into the aerosol-generating substrate of the aerosol-generating article. Other known electrically-operated aerosol-generating devices comprise one or more external heating elements. For example, WO 2020/115151 A1 discloses an aerosolgenerating system comprising an aerosol-generating article and an electrically-operated aerosol-generating device comprising an external heating element that circumscribes the periphery of the aerosol-generating article.

Electrically-operated aerosol-generating devices comprising an inductor configured to inductively heat aerosol-generating substrates of heated aerosol-generating articles are also known. For example, WO 2015/176898 A1 discloses an aerosol-generating system comprising an aerosol-generating article comprising an elongate susceptor in thermal contact with the aerosol-generating substrate and an electrically-operated aerosol-generating device having an inductor for heating the aerosol-generating substrate. In use, the fluctuating or alternating electromagnetic field produced by the inductor induces eddy currents in the susceptor, causing the susceptor to heat up as a result of one or both of resistive losses (Joule heating) and, where the susceptor is magnetic, hysteresis loses. Heat generated in the susceptor is transferred to the aerosol-generating substrate by conduction.

It is known that the aerosol-generating substrate of an aerosol-generating article may absorb water from the air, for example, during storage of the aerosol-generating article . The aerosol-generating substrate may absorb water from the air until an equilibrium point is reached, at which point the water content of the aerosol-generating substrate may be equal to the relative humidity of the environment.

Heating of the aerosol-generating substrate during use of the aerosol-generating article may result in evaporation of the absorbed water, for example, prior to the evaporation of nicotine and glycerine in the aerosol-generating substrate. The resulting water vapour may carry a significant amount of energy and may increase the temperature of aerosol delivered to a user. This may result in an uncomfortable sensory experience for the user during at least the initial puffs by the user. This phenomenon is referred to as ‘warm aerosol perception’ and may be particularly problematic in warm and humid environments. In some instances, warm aerosol perception may deter a user from using the aerosol-generating article.

Aerosol-generating articles comprising an upstream element are known. Some known aerosol-generating articles comprise an upstream element formed of the same material as a mouthpiece element. For example, an aerosol-generating article may comprise: an upstream element being a plug of cellulose acetate tow, and a mouthpiece element being another plug of cellulose acetate tow. It may be difficult for a user to distinguish between the upstream end and the mouth end of known aerosol-generating articles. A user may inadvertently insert the mouth end of the aerosol-generating article into a cavity of an aerosol-generating device, which may result in inefficient heating of the aerosol-generating substrate. The user may draw on the upstream end of the aerosol-generating article, which may not provide a desired mouthfeel or sensory experience.

After use of an aerosol-generating article, a user may not be able to tell whether the aerosol-generating article has already been heated to generate an aerosol. Subsequent use of the same aerosol-generating article may result in aerosol being delivered to the user that is of poorer quality than aerosol generated by an aerosol-generating article that has not previously been used. A user may inadvertently use an already spent aerosol-generating article, for example, when the user places the spent aerosol-generating article back into its pack for disposal later and then picks out an aerosol-generating article from the same pack.

It would be desirable to provide an aerosol-generating article in which the sensory experience for the user and the quality of aerosol delivered to the user is improved compared to known aerosol-generating articles.

The present disclosure relates to an aerosol-generating article comprising an aerosolgenerating substrate. The aerosol-generating article may comprise an upstream element located upstream of the aerosol-generating substrate. The upstream element may comprise a longitudinal airflow channel. The upstream element may comprise an obstruction element for obstructing the longitudinal airflow channel. The upstream element may be configured to change state upon heating during use of the aerosol-generating article. The upstream element may be configured to change state from an initial state to a final state. In the initial state, the longitudinal airflow channel may be obstructed by the obstruction element. The longitudinal airflow channel being obstructed by the obstruction element may substantially prevent airflow through the longitudinal airflow channel. In the final state, the longitudinal airflow channel may be at least partially open. The longitudinal airflow channel may be at least partially open to allow airflow through the longitudinal airflow channel. The upstream element may have a lower resistance to draw in the final state than in the initial state.

According to a first aspect of the present disclosure, there is provided an aerosolgenerating article comprising: an aerosol-generating substrate; an upstream element located upstream of the aerosol-generating substrate, the upstream element comprising a longitudinal airflow channel and an obstruction element for obstructing the longitudinal airflow channel, wherein the upstream element is configured to change state upon heating during use of the aerosol-generating article from: an initial state, in which the longitudinal airflow channel is obstructed by the obstruction element to substantially prevent airflow through the longitudinal airflow channel, to a final state, in which the longitudinal airflow channel is at least partially open to allow airflow through the longitudinal airflow channel, wherein the upstream element has a lower resistance to draw in the final state than in the initial state.

The present disclosure also relates to an aerosol-generating system. The aerosolgenerating system may comprise an aerosol-generating article as described above. The aerosol-generating system may comprise an aerosol-generating device. The aerosolgenerating device may be configured to heat the aerosol-generating substrate of the aerosolgenerating article.

According to a second aspect of the present disclosure, there is provided an aerosolgenerating system comprising: an aerosol-generating article according to the first aspect of the present disclosure; and an aerosol-generating device configured to heat the aerosolgenerating substrate of the aerosol-generating article, wherein the aerosol-generating device comprises a housing defining a cavity configured to receive the aerosol-generating article.

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

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

As used herein with reference to the present disclosure, the term “aerosol” is used to describe a dispersion of solid particles, or liquid droplets, or a combination of solid particles and liquid droplets, in a gas. The aerosol may be visible or invisible. The aerosol 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 with reference to the present disclosure, the term “aerosol-generating device” is used to describe a device that interacts with the aerosol-generating substrate of the aerosol-generating article to generate an aerosol.

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

Aerosol-generating articles according to the present disclosure have a distal end. The distal end is opposite the proximal end. The distal end of the aerosol-generating article may also be referred to as the upstream end of the aerosol-generating article.

Components of aerosol-generating articles according to the present disclosure may be described as being upstream or downstream of one another based on their relative positions between the proximal end of the aerosol-generating article and the distal end of the aerosolgenerating article.

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

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

As used herein with reference to the present disclosure, 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 a component of the aerosol-generating article refer to the transverse cross-section.

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

Unless otherwise stated, the resistance to draw (RTD) of the aerosol-generating article or a component of the aerosol-generating article is measured in accordance with ISO 6565- 2015 at a volumetric flow rate of about 17.5 millilitres per second at the proximal end or downstream end of the aerosol-generating article or the component thereof at a temperature of about 22 degrees Celsius, a pressure of about 101 kPa (about 760 Torr) and a relative humidity of about 60%.

For the purposes of the present disclosure, the resistance to draw of the aerosolgenerating article when the upstream element is in the final state is considered to be the same as the resistance to draw of the aerosol-generating article after heating of the aerosolgenerating article, such that the upstream element changes state to the final state, and then subsequent cooling of the aerosol-generating article. For example, the resistance to draw of the aerosol-generating article when the upstream element is in the final state may be considered to be the same as the resistance to draw of the aerosol-generating article after the aerosol-generating article was heated during use of the aerosol-generating article and then subsequently cooled to about 22 degrees Celsius.

Similarly, for the purposes of the present disclosure, the resistance to draw of the upstream element when the upstream element is in the final state is considered to be the same as the resistance to draw of the upstream element after heating of the upstream element, such that the upstream element changes state to the final state, and then subsequent cooling of the upstream element. Aerosol-generating articles according to the first aspect of the present disclosure comprise an upstream element located upstream of an aerosol-generating substrate, the upstream element comprising a longitudinal airflow channel and an obstruction element for obstructing the longitudinal airflow channel, wherein the upstream element is configured to change state upon heating during use of the aerosol-generating article from: an initial state, in which the longitudinal airflow channel is obstructed by the obstruction element to substantially prevent airflow through the longitudinal airflow channel, to a final state, in which the longitudinal airflow channel is at least partially open to allow airflow through the longitudinal airflow channel, wherein the upstream element has a lower resistance to draw in the final state than in the initial state.

Inclusion of an upstream element having a lower resistance to draw in the final state than in the initial state may advantageously mitigate or prevent warm aerosol perception by a user. Prior to use of the aerosol-generating article, the upstream element may be in the initial state; upon heating during use of the aerosol-generating article, the upstream element may transition to the final state; the resistance to draw of the upstream element decreasing from the initial state to the final state. The decrease in the resistance to draw of the upstream element may be such that less air is drawn into the aerosol-generating article through the upstream element during the initial puffs by a user than is drawn into the aerosol-generating article through the upstream element during later puffs by the user. Accordingly, less aerosol may be delivered to the user during the initial puffs than during the later puffs. This may help to minimise or avoid uncomfortably warm aerosol being delivered to a user and may improve the sensory experience of the user.

As discussed further below, the aerosol-generating article may comprise a ventilation zone located downstream of the aerosol-generating substrate. Air drawn into the aerosolgenerating article through the ventilation zone may help to cool the stream of aerosol generated by the aerosol-generating substrate prior to delivery to a user. Increasing the resistance to draw of the upstream element may increase the ventilation level of the aerosolgenerating article. The change in the resistance to draw of the upstream element on the change of state from the initial state to the final state may be such that the aerosol-generating article has a higher ventilation level during the initial puffs than during the later puffs. This may be such that a level of cooling of the stream of aerosol generated by the aerosolgenerating substrate is higher during the initial puffs than during the later puffs. The adjustment in the level of cooling of the aerosol during the user experience may counteract warm aerosol perception during the initial puffs by a user while providing an acceptable aerosol of suitable temperature during the later puffs. This may improve the sensory experience of the user. The obstruction element may provide a visual sign to a user of the upstream end of the aerosol-generating article. This may help to guide a user to correctly insert the upstream end of the aerosol-generating article into a cavity of an aerosol-generating device. Correct insertion of the aerosol-generating article into the aerosol-generating device may optimise heating of the aerosol-generating substrate of the aerosol-generating article to improve the quality of aerosol delivered to the user.

The user may identify the mouth end of the aerosol-generating article to place in their mouth during use of the aerosol-generating article. Doing so may provide a user with a desired mouthfeel and sensory experience.

During use of the aerosol-generating article, the upstream element transitions from the initial state in which the longitudinal airflow channel is obstructed by the obstruction element to the final state in which the longitudinal airflow channel is at least partially open. The transition from the initial state to the final state may provide a visual sign to a user that the aerosol-generating article has been used. Such visual sign may help a user avoid reusing an already spent aerosol-generating article. This may help a user avoid being provided with aerosol of a poor quality.

The upstream element is configured to change state upon heating during use of the aerosol-generating article from the initial state to the final state.

The initial state of the upstream element may correspond to the state of the upstream element prior to use of the aerosol-generating article. The initial state of the upstream element may correspond to the state of the upstream element prior to heating of the aerosol-generating article, for example by an aerosol-generating device.

The upstream element may be in the initial state for an initial period after the initiation of heating of the aerosol-generating article. For example, the upstream element may be in the initial state for about the first minute from initiation of heating of the aerosol-generating article. The upstream element may be in the initial state until soon after the first, second or third puff by a user.

The upstream element may be in the final state during the majority of the user experience. For example, , the upstream element may be in the final state from about the first minute from initiation of heating of the aerosol-generating article to at least the end of the user experience. The upstream element may be in the final state from soon after the first, second or third puff by a user until the end of the user experience.

The obstruction element may comprise a heat sensitive material. The obstruction element may be heat sensitive.

During the change of state of the upstream element from the initial state to the final state, the viscosity of the obstruction element may decrease. This may be such that the obstruction element flows during the change of state of the upstream element from the initial state to the final state.

The obstruction element may be absorbed by another component of the upstream element when the upstream element is in the final state. For example, where the upstream element comprises a plug of cellulose acetate tow, the obstruction element may be absorbed by the plug of cellulose acetate tow when the upstream element is in the final state.

The longitudinal airflow channel may be substantially empty when the upstream element is in the final state. The longitudinal airflow channel may be substantially unobstructed when the upstream element is in the final state.

The obstruction element may melt during the change of state of the upstream element from the initial state to the final state.

The melting point of the obstruction element may be selected based on a desired timing of the change of state of the upstream element from the initial state to the final state during use of the aerosol-generating article. The melting point of the obstruction element may be sufficiently high to avoid the upstream element changing state from the initial state to the final state during storage of the aerosol-generating article and prior to heating and use of the aerosol-generating article. The melting point of the obstruction element may be sufficiently low such that the upstream element changes state from the initial state to the final state during the heating of the aerosol-generating article, for example by an aerosol-generating device. The melting point of the obstruction element may be selected such that the upstream element changes state from the initial state to the final state once a significant amount of water in the aerosol-generating substrate has evaporated, but prior to a vaporisation of a significant amount of other components of the aerosol-generating substrate. This may advantageously avoid warm aerosol perception whilst providing a user with a desired sensory experience and improved aerosol quality. The melting point of the obstruction element may be such that the upstream element changes state from the initial state to the final state soon after a first, second, or third puff by a user. The melting point of the obstruction element may be such that the upstream element changes state from the initial state to the final state about a minute after the initiation of heating of the aerosol-generating article, for example, by an aerosol-generating device.

The obstruction element may have a melting point of between about 40 degrees Celsius and about 220 degrees Celsius, between about 40 degrees Celsius and about 150 degrees Celsius, between about 40 degrees Celsius and about 100 degrees Celsius, or between about 40 degrees Celsius and about 80 degrees Celsius.

The obstruction element may have a melting point of between about 45 degrees Celsius and about 220 degrees Celsius, between about 45 degrees Celsius and about 150 degrees Celsius, between about 45 degrees Celsius and about 100 degrees Celsius, or between about 45 degrees Celsius and about 80 degrees Celsius.

The obstruction element may have a melting point of between about 50 degrees Celsius and about 220 degrees Celsius, between about 50 degrees Celsius and about 150 degrees Celsius, between about 50 degrees Celsius and about 100 degrees Celsius, or between about 50 degrees Celsius and about 80 degrees Celsius.

After heating of the aerosol-generating article such that the upstream element changes state to the final state, the obstruction element may solidify upon subsequent cooling of the aerosol-generating article. The shape of the obstruction element when the upstream element is in the final state may be substantially the same as the shape of the obstruction element following subsequent cooling of the aerosol-generating article.

The shape of the obstruction element following both heating of the aerosol-generating article (such that the upstream element changes state to the final state) and subsequent cooling of the aerosol-generating article may be different to the shape of the obstruction element when the upstream element is in the initial state.

The obstruction element may be in the form of a solid when the upstream element is in the initial state. The obstruction element may be in the form of a solid rod when the upstream element is in the initial state.

The obstruction element may be in the form of a powder when the upstream element is in the initial state. For example, the obstruction element may be in the form of a solid rod of compress powder. As another example, the obstruction element may be in the form of loose powder.

The obstruction element may be in the form of a gel when the upstream element is in the initial state.

The obstruction element may be in the form of a liquid when the upstream element is in the final state. The obstruction element may be in the form of a gel when the upstream element is in the final state.

The obstruction element may comprise a wax. The obstruction element may comprise a lipid.

The obstruction element may comprise one or more of: stearin, paraffin, glycerine, Arabic gum, and a sugar.

Preferably the obstruction element comprises stearin. The obstruction element may comprise stearin in an amount of at least about 80 percent by weight, or at least about 90 percent by weight on a dry weight basis.

The obstruction element may comprise both stearin and glycerine.

The stearin may be in the form of a powder when the upstream element is in the initial state. The upstream element has a lower resistance to draw in the final state than in the initial state. The change in the resistance to draw of the upstream element on the change of state from the initial state to the final state may help to counteract warm aerosol perception during the initial puffs while providing an acceptable aerosol of suitable temperature during the later puffs. This may improve the sensory experience of the user throughout the entire user experience.

The resistance to draw of the upstream element in the initial state may be such that the provision of the upstream element counteracts warm aerosol perception during the initial puffs by a user. Increasing the resistance to draw of the upstream element may reduce the amount of air drawn into the aerosol-generating article via the upstream element. This may reduce the amount of aerosol delivered to a user. Reducing the amount of aerosol delivered to a user during the initial puffs by a user may help to counteract warm aerosol perception.

The resistance to draw of the upstream element in the final state may be such that the aerosol-generating article provides a user with a desired sensory experience for a majority of the user experience and after the initial few puffs by the user. For example, the resistance to draw of the upstream element in the final state may be such that the force needed to draw air through the aerosol-generating article is desired and the aerosol delivered to the user is at a desired temperature and has a desired composition.

The resistance to draw of the upstream element may vary depending on the overall configuration of the aerosol-generating article.

The resistance to draw of the upstream element in the final state may be less than the resistance to draw of the upstream element in the initial state by at least about 20 percent, at least about 40 percent, or at least about 60 percent. In some instances, the resistance to draw of the upstream element in the final state may be less than the resistance to draw of the upstream element in the initial state by at least about 90 percent.

The resistance to draw of the upstream element in the final state may be less than the resistance to draw of the upstream element in the initial state by less than or equal to about 95 percent, less than or equal to about 90 percent, or less than or equal to about 85 percent.

The resistance to draw of the upstream element in the final state may be less than the resistance to draw of the upstream element in the initial state by between about 20 percent and about 95 percent, between about 20 percent and about 90 percent, or between about 20 percent and about 85 percent.

The resistance to draw of the upstream element in the final state may be less than the resistance to draw of the upstream element in the initial state by between about 40 percent and about 95 percent, between about 40 percent and about 90 percent, or between about 40 percent and about 85 percent. The resistance to draw of the upstream element in the final state may be less than the resistance to draw of the upstream element in the initial state by between about 60 percent and about 95 percent, between about 60 percent and about 90 percent, or between about 60 percent and about 85 percent.

In some instances, the resistance to draw of the upstream element in the final state may be less than the resistance to draw of the upstream element in the initial state by between about 90 percent and about 95 percent.

The resistance to draw of the upstream element in the final state may be less than the resistance to draw of the upstream element in the initial state by at least about 5 millimetres H2O, at least about 15 millimetres H2O, or at least about 25 millimetres H2O. In some instances, the resistance to draw of the upstream element in the final state may be less than the resistance to draw of the upstream element in the final state by at least about 90 millimetres H₂O.

The resistance to draw of the upstream element in the final state may be less than the resistance to draw of the upstream element in the initial state by less than or equal to about 200 millimetres H2O. The resistance to draw of the upstream element in the final state may be less than the resistance to draw of the upstream element in the initial state by less than or equal to about 90 millimetres H2O, less than or equal to about 75 millimetres H2O, or less than or equal to about 60 millimetres H2O.

The resistance to draw of the upstream element in the final state may be less than the resistance to draw of the upstream element in the initial state by between about 5 millimetres H2O and about 200 millimetres H2O, between about 5 millimetres H2O and about 90 millimetres H2O, between about 5 millimetres H2O and about 75 millimetres H2O, or between about 5 millimetres H2O and about 60 millimetres H2O.

The resistance to draw of the upstream element in the final state may be less than the resistance to draw of the upstream element in the initial state by between about 15 millimetres H2O and about 200 millimetres H2O, between about 15 millimetres H2O and about 90 millimetres H2O, between about 15 millimetres H2O and about 75 millimetres H2O, or between about 15 millimetres H2O and about 60 millimetres H2O.

The resistance to draw of the upstream element in the final state may be less than the resistance to draw of the upstream element in the initial state by between about 25 millimetres H2O and about 200 millimetres H2O, between about 25 millimetres H2O and about 90 millimetres H2O, between about 25 millimetres H2O and about 75 millimetres H2O, or between about 25 millimetres H2O and about 60 millimetres H2O.

In some instances, the resistance to draw of the upstream element in the final state may be less than the resistance to draw of the upstream element in the initial state by between about 90 millimetres H2O and about 200 millimetres H2O. The resistance to draw of the upstream element in the initial state may be at least about 15 millimetres H2O, at least about 25 millimetres H2O, or at least about 35 millimetres H2O. In some instances, the resistance to draw of the upstream element in the initial state may be at least about 100 millimetres H2O.

The resistance to draw of the upstream element in the initial state may be less than or equal to about 200 millimetres H2O. The resistance to draw of the upstream element in the initial state may be less than or equal to about 100 millimetres H2O, less than or equal to about 85 millimetres H2O, or less than or equal to about 70 millimetres H2O.

The resistance to draw of the upstream element in the final state may be at least about 2 millimetres H2O, at least about 5 millimetres H2O, or at least about 10 millimetres H2O.

The resistance to draw of the upstream element in the final state may be less than or equal to about 25 millimetres H2O, less than or equal to about 20 millimetres H2O, or less than or equal to about 15 millimetres H2O.

On a decrease in the resistance to draw of the upstream element on a change of state from the initial state to the final state, the overall resistance to draw of the aerosol-generating article may also decrease .

The overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosolgenerating article when the upstream element is in the initial state.

A reduction in the overall resistance to draw of the aerosol-generating article on a change of state of the upstream element from the initial state to the final state may help to counteract warm aerosol perception during the initial puffs while providing an acceptable aerosol of suitable temperature during the later puffs. This may improve the sensory experience of the user throughout the entire user experience.

In some instances, the resistance to draw of the aerosol-generating article when the upstream element is in the initial state may be relatively large. In some instances, the difference in the resistance to draw of the aerosol-generating article when the upstream element is in the initial state and when the upstream element is in the final state may be relatively large. These instances may be, for example, where the obstruction element has a relatively large cross-sectional area, or where the upstream element comprises a plurality of obstruction elements and the total cross-sectional area of the plurality of cross-sectional elements is relatively large. In these instances, the obstruction element may be provided as a coating or a layer on an end face of an upstream plug of the upstream element.

The overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosolgenerating article when the upstream element is in the initial state by at least about 5 percent, at least about 10 percent, or at least about 15 percent. In some instances, the overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosol-generating article when the upstream element is in the initial state by at least about 30 percent.

The overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosolgenerating article when the upstream element is in the initial state by less than or equal to about 80 percent, less than or equal to about 60 percent, or less than or equal to about 40 percent.

The overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosolgenerating article when the upstream element is in the initial state by between about 5 percent and about 80 percent, between about 5 percent and about 60 percent, or between about 5 percent and about 40 percent.

The overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosolgenerating article when the upstream element is in the initial state by between about 10 percent and about 80 percent, between about 10 percent and about 60 percent, or between about 10 percent and about 40 percent.

The overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosolgenerating article when the upstream element is in the initial state by between about 15 percent and about 80 percent, between about 15 percent and about 60 percent, or between about 15 percent and about 40 percent.

The overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosolgenerating article when the upstream element is in the initial state by between about 30 percent and about 80 percent, between about 30 percent and about 60 percent, or between about 30 percent and about 40 percent.

The overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosolgenerating article when the upstream element is in the initial state by at least about 5 millimetres H2O, at least about 8 millimetres H2O, or at least about 12 millimetres H2O. In some instances, the overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosol-generating article by at least about 50 millimetres H2O.

The overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosol- generating article when the upstream element is in the initial state by less than or equal to about 120 millimetres H2O. The overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosol-generating article when the upstream element is in the initial state by less than or equal to about 40 millimetres H2O, less than or equal to about 30 millimetres H2O, or less than or equal to about 20 millimetres H2O.

The overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosolgenerating article when the upstream element is in the initial state by between about 5 millimetres H2O and about 120 millimetres H2O, between about 5 millimetres H2O and about 40 millimetres H2O, between about 5 millimetres H2O and about 30 millimetres H2O between about 5 millimetres H2O and about 20 millimetres H2O.

The overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosolgenerating article when the upstream element is in the initial state by between about 8 millimetres H2O and about 120 millimetres H2O, between about 8 millimetres H2O and about 40 millimetres H2O, between about 8 millimetres H2O and about 30 millimetres H2O between about 8 millimetres H2O and about 20 millimetres H2O.

The overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosolgenerating article when the upstream element is in the initial state by between about 12 millimetres H2O and about 120 millimetres H2O, between about 12 millimetres H2O and about 40 millimetres H2O, between about 12 millimetres H2O and about 30 millimetres H2O between about 12 millimetres H2O and about 20 millimetres H2O.

In some instances, the overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than the overall resistance to draw of the aerosol-generating article when the upstream element is in the initial state by between about 50 millimetres H2O and about 120 millimetres H2O.

The overall resistance to draw of the aerosol-generating article when the upstream element is in the initial state may be at least about 40 millimetres H2O, at least about 45 millimetres H2O, or at least about 50 millimetres H2O. In some instances, the overall resistance to draw of the aerosol-generating article when the upstream element is in the initial state may be at least about 100 millimetres H2O.

The overall resistance to draw of the aerosol-generating article when the upstream element is in the initial state may be less than or equal to about 200 millimetres H2O. The overall resistance to draw of the aerosol-generating article when the upstream element is in the initial state may be less than or equal to about 100 millimetres H2O, less than or equal to about 85 millimetres H2O, or less than or equal to about 70 millimetres H2O.

The overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be at least about 25 millimetres H2O, at least about 30 millimetres H2O, or at least about 35 millimetres H2O.

The overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than or equal to about 80 millimetres H2O, less than or equal to about 70 millimetres H2O, or less than or equal to about 60 millimetres H2O.

As discussed further below, the aerosol-generating article may comprise a downstream section located downstream of the aerosol-generating substrate. The downstream section may comprise a ventilation zone.

A ventilation level of the aerosol-generating article when the upstream element is in the final state may be less than a ventilation level of the aerosol-generating article when the upstream element is in the initial state.

As used herein with reference to the present disclosure, the term “ventilation level” is used to denote a volume ratio between the airflow admitted into the aerosol-generating article via a ventilation zone (ventilation airflow) and the sum of the aerosol airflow and the ventilation airflow. The greater the ventilation level, the higher the dilution of the aerosol flow delivered to a user. Increasing the ventilation level may increase a level of cooling of the aerosol flow prior to delivery to a user.

A change in the ventilation level of the aerosol-generating article when the upstream element changes state from the initial state to the final state during the user experience may help to counteract warm aerosol percent during the initial puffs by a user while providing an acceptable aerosol of suitable temperature during the later puffs.

A greater difference in the resistance to draw of the upstream element or of the aerosol-generating article when the upstream element is in the initial state and when the upstream element is in the final state may result in a greater difference in the ventilation level of the aerosol-generating article when the upstream element is in the initial state and when the upstream element is in the final state.

In some instances, a ventilation level of the aerosol-generating article when the upstream element is in the initial state may be relatively large. In some instances, the difference in the ventilation level of the aerosol-generating article when the upstream element is in the initial state and when the upstream element is in the final state may be relatively large. These instances may be, for example, where the obstruction element has a relatively large cross-sectional area, or where the upstream element comprises a plurality of obstruction elements and the total cross-sectional area of the plurality of cross-sectional elements is relatively large. In these instances, the obstruction element may be provided as a coating on an end face of an upstream plug of the upstream element.

A ventilation of the aerosol-generating article when the upstream element is in the final state may be less than a ventilation level of the aerosol-generating article when the upstream element is in the initial state by at least about 4 percentage points, at least about 6 percentage points, or at least about 8 percentage points. In some instances, a ventilation of the aerosolgenerating article when the upstream element is in the final state may be less than a ventilation level of the aerosol-generating article when the upstream element is in the initial state by at least about 30 percentage points.

A ventilation level of the aerosol-generating article when the upstream element is in the final state may be less than a ventilation level of the aerosol-generating article when the upstream element is in the initial state by less than or equal to about 60 percentage points. A ventilation level of the aerosol-generating article when the upstream element is in the final state may be less than a ventilation level of the aerosol-generating article when the upstream element is in the initial state by less than or equal to about 25 percentage points, less than or equal to about 20 percentage points, or less than or equal to about 15 percentage points.

A ventilation level of the aerosol-generating article when the upstream element is in the final state may be less than a ventilation level of the aerosol-generating article when the upstream element is in the initial state by between about 4 percentage points and about 60 percentage points, between about 4 percentage points and about 25 percentage points, between about 4 percentage points and about 20 percentage points, or between about 4 percentage points and about 15 percentage points.

A ventilation level of the aerosol-generating article when the upstream element is in the final state may be less than a ventilation level of the aerosol-generating article when the upstream element is in the initial state by between about 6 percentage points and about 60 percentage points, between about 6 percentage points and about 25 percentage points, between about 6 percentage points and about 20 percentage points, or between about 6 percentage points and about 15 percentage points.

A ventilation level of the aerosol-generating article when the upstream element is in the final state may be less than a ventilation level of the aerosol-generating article when the upstream element is in the initial state by between about 8 percentage points and about 60 percentage points, between about 8 percentage points and about 25 percentage points, between about 8 percentage points and about 20 percentage points, or between about 8 percentage points and about 15 percentage points.

In some instances, a ventilation level of the aerosol-generating article when the upstream element is in the final state may be less than a ventilation level of the aerosol- generating article when the upstream element is in the initial state by between about 30 percentage points and about 60 percentage points.

When the upstream element is in the initial state, the aerosol-generating article may have a ventilation level of at least about 30 percent, at least about 35 percent, or at least about 40 percent. In some instances, when the upstream element is in the initial state, the aerosolgenerating article may have a ventilation level of at least about 60 percent.

When the upstream element is in the initial state, the aerosol-generating article may have a ventilation level of less than or equal to about 80 percent, less than or equal to about 70 percent, or less than or equal to about 60 percent.

When the upstream element is in the initial state, the aerosol-generating article may have a ventilation level of between about 30 percent and about 80 percent, between about 30 percent and about 70 percent, or between about 30 percent and about 60 percent.

When the upstream element is in the initial state, the aerosol-generating article may have a ventilation level of between about 35 percent and about 80 percent, between about 35 percent and about 70 percent, or between about 35 percent and about 60 percent.

When the upstream element is in the initial state, the aerosol-generating article may have a ventilation level of between about 40 percent and about 80 percent, between about 40 percent and about 70 percent, or between about 40 percent and about 60 percent.

In some instances, when the upstream element is in the initial state, the aerosolgenerating article may have a ventilation level of between about 60 percent and about 80 percent, or between about 60 percent and about 70 percent.

When the upstream element is in the initial state, the obstruction element may substantially prevent airflow through the upstream element. Where this is the case, when the upstream element is in the initial state, the aerosol-generating article may have a ventilation level of about 100 percent. In other words, substantially all air entering the aerosol-generating article may be drawn into the aerosol-generating article via the ventilation zone.

When the upstream element is in the final state, the aerosol-generating article may have a ventilation level of at least about 15 percent, at least about 20 percent, or at least about 25 percent.

When the upstream element is in the final state, the aerosol-generating article may have a ventilation level of less than or equal to about 60 percent, less than or equal to about 55 percent, or less than or equal to about 50 percent.

When the upstream element is in the final state, the aerosol-generating article may have a ventilation level of between about 15 percent and about 60 percent, or between about 15 percent and about 55 percent, or between about 15 percent and about 50 percent. When the upstream element is in the final state, the aerosol-generating article may have a ventilation level of between about 20 percent and about 60 percent, or between about 20 percent and about 55 percent, or between about 20 percent and about 50 percent.

When the upstream element is in the final state, the aerosol-generating article may have a ventilation level of between about 25 percent and about 65 percent, or between about 25 percent and about 55 percent, or between about 25 percent and about 50 percent.

For example, when the upstream element is in the final state, the aerosol-generating article may have a ventilation level of about 50 percent.

When the upstream element is in the initial state, the obstruction element may be located at least partially in the longitudinal airflow channel to substantially prevent airflow through the longitudinal channel. When the upstream element is in the initial state, the obstruction element may be located entirely in the longitudinal airflow channel.

When the upstream element is in the initial state, the obstruction element may be located at the upstream end of the upstream element. When the upstream element is in the initial state, the obstruction element may extend from the upstream end of the upstream element towards the downstream end of the upstream element. The obstruction element being located at the upstream end of the upstream element may act as a visual sign to a user of the upstream end of the aerosol-generating article. When the upstream element changes state from the initial state to the final state, the obstruction element may move such that configuration and position of the obstruction element in the final state may indicate to a user that the aerosol-generating article has been used.

When the upstream element is in the initial state, the obstruction element may be located at the downstream end of the upstream element. When the upstream element is in the initial state, the obstruction element may extend from the downstream end of the upstream element towards the upstream end of the upstream element. During use of the aerosolgenerating article, the aerosol-generating article may be oriented such that the upstream end thereof is located vertically below the downstream end thereof. The obstruction element being located at the downstream end of the upstream element when the upstream element is in the initial state may mean that upon heating during use of the aerosol-generating article and during the change of state of the upstream element from the initial state to the final state, the obstruction element flows towards the upstream end of the aerosol-generating article and away from the aerosol-generating substrate. During the change of state of the upstream element, the obstruction element may be absorbed by another component of the upstream element, such as an upstream plug of the upstream element.

When the upstream element is in the initial state, the obstruction element may extend from the upstream end of the upstream element to the downstream end of the upstream element. This may simplify manufacturing of the upstream element, since this may enable multiple upstream elements to be produced from a single continuous rod. The obstruction element extending from the upstream end of the upstream element to the downstream end of the upstream element may simplify assembling of the aerosol-generating article, since the orientation in which the upstream element is assembled in the aerosol-generating article may be immaterial.

When the upstream element is in the initial state, the obstruction element may cover the longitudinal airflow channel to substantially prevent airflow through the longitudinal airflow channel. For example, the obstruction element may be provided as an obstruction layer at the upstream end of the upstream element, such as an obstruction layer on the upstream end face of an upstream plug of the upstream element. As another example, the obstruction element may be provided as an obstruction layer at the downstream end of the upstream element, such as an obstruction layer on the downstream end face of an upstream plug of the upstream element.

Where the upstream element comprises one or more longitudinal airflow channels extending through an upstream plug of the upstream element, an obstruction element provided as an obstruction layer on an end face of the upstream element may be such that each of the one or more longitudinal airflow channels are obstructed by the obstruction layer when the upstream element is in the initial state.

Where the obstruction element is in the form of an obstruction layer at an end of the upstream element, the obstruction element may be a coating at an end of the upstream element. For example, the obstruction element may be provided as a coating on an end face of an upstream plug of the upstream element. The obstruction element may be sprayed onto the end face of the upstream plug of the upstream element.

When the upstream element is in the initial state, the obstruction element may be completely embedded within another component of the upstream element, such as an upstream plug of the upstream element. This may help to ensure that the obstruction element is contained within the upstream element one or both of when the upstream element is in the initial state and when the upstream element changes state from the initial state to the final state. This may be particularly advantageous where the obstruction element is in the form of a powder when the upstream element is in the initial state.

The longitudinal airflow channel may have a substantially circular cross-sectional shape. The longitudinal airflow channel may be substantially cylindrical.

The size of the longitudinal airflow channel may be selected based on a desired resistance to draw of the upstream element in the initial state and a desired resistance to draw of the upstream element in the final state. Increasing the size of the longitudinal airflow channel may increase a reduction in the resistance to draw of the upstream element on the change of state from the initial state to the final state. This is because when the upstream element is in the final state, the longitudinal airflow channel may provide a substantially unobstructed pathway for air to flow through. Increasing the size of the substantially unobstructed pathway of the upstream element when may decrease the resistance to draw of the upstream element.

The longitudinal airflow channel may have a width of at least about 0.5 millimetres, at least about 0.7 millimetres, or at least about 1 millimetre.

The longitudinal airflow channel may have a width of less than or equal to about 3 millimetres, less than or equal to about 2.5 millimetres, or less than or equal to about 2 millimetres.

The longitudinal airflow channel may have a width of between about 0.5 millimetres and about 3 millimetres, between about 0.5 millimetres and about 2.5 millimetres, or between about 0.5 millimetres and about 2 millimetres.

The longitudinal airflow channel may have a width of between about 0.7 millimetres and about 3 millimetres, between about 0.7 millimetres and about 2.5 millimetres, or between about 0.7 millimetres and about 2 millimetres.

The longitudinal airflow channel may have a width of between about 1 millimetre and about 3 millimetres, between about 1 millimetre and about 2.5 millimetres, or between about 1 millimetre and about 2 millimetres.

The longitudinal airflow channel may extend along substantially the entire length of the upstream element. The longitudinal airflow channel may extend substantially from the upstream end of the upstream element to the downstream end of the upstream element. For example, the longitudinal airflow channel may extend the entire length of an upstream plug of the upstream element. Where the longitudinal airflow channel extends along substantially the entire length of the upstream element, the reduction in the resistance to draw of the upstream element from the initial state to the final state may be greater than in an upstream element where the longitudinal airflow channel does not extend substantially the entire length of the upstream element. This is because, where the longitudinal airflow channel extends substantially the entire length of the upstream element, the upstream element in the final state may have a substantially unobstructed longitudinal airflow channel extending substantially the entire length of the upstream element which provides a pathway with a low resistance for air to flow through.

The longitudinal airflow channel may not extend the entire length of upstream element.

The longitudinal airflow channel may extend along at least about 20 percent of the length of the upstream element, at least about 50 percent of the length of the upstream element, or at least about 80 percent of the length of the upstream element.

The longitudinal airflow channel may extend up to the entire length of the upstream element. For example, the longitudinal airflow channel may extend up to about 90 percent of the length of the upstream element, or up to about 80 percent of the length of the upstream element.

The longitudinal airflow channel may extend along between about 20 percent and about 100 percent of the length of the upstream element, between about 50 percent and about 100 percent of the length of the upstream element, or between about 80 percent and about 100 percent of the length of the upstream element.

The longitudinal airflow channel may extend along between about 20 percent and about 90 percent of the length of the upstream element, between about 50 percent and about 90 percent of the length of the upstream element, or between about 80 percent and about 90 percent of the length of the upstream element.

The longitudinal airflow channel may extend along between about 20 percent and about 80 percent of the length of the upstream element, or between about 50 percent and about 80 percent of the length of the upstream element.

The longitudinal airflow channel may have a length of at least about 1 millimetre, at least about 2.5 millimetres, or at least about 4 millimetres. The longitudinal airflow channel may have a length of less than or equal to about 10 millimetres, less than or equal to about 8 millimetres or less than or equal to about 6 millimetres. For example, the longitudinal airflow channel may have a length of about 5 millimetres.

The width, cross-sectional area, length, size and shape of the longitudinal airflow channel discussed herein may refer to width, cross-sectional area, length, size and shape of the longitudinal airflow channel when the upstream element is in one or both of the initial state and the final state.

The width, cross-sectional area, length, size and shape of the longitudinal airflow channel may be unchanged upon a change of state of the upstream element from the initial state to the final state.

The upstream element may comprise a single longitudinal airflow channel. The width, cross-sectional area, length, size and shape of the longitudinal airflow channel described herein may apply to the single longitudinal airflow channel.

The obstruction element may substantially fill the volume of the longitudinal airflow channel.

The size and shape of the obstruction element may be substantially the same as the size and shape of the longitudinal airflow channel. This may particularly be the case where the obstruction element is located substantially entirely within the longitudinal airflow channel when the upstream element is in the initial state. The size and shape of the obstruction element being substantially the same as the size and shape of the longitudinal airflow channel may be such that the longitudinal airflow channel is obstructed by the obstruction element to substantially prevent airflow through the longitudinal airflow channel when the upstream element is in the initial state.

The obstruction element may have a substantially circular cross-sectional shape. The obstruction element may be substantially cylindrical.

The obstruction element may have a width substantially the same as a width of the longitudinal airflow channel.

The obstruction element may have a width of at least about 0.5 millimetres, at least about 0.7 millimetres, or at least about 1 millimetre.

The obstruction element may have a width of less than or equal to about 3 millimetres, less than or equal to about 2.5 millimetres, or less than or equal to about 2 millimetres.

The obstruction element may have a width of between about 0.5 millimetres and about 3 millimetres, between about 0.5 millimetres and about 2.5 millimetres, or between about 0.5 millimetres and about 2 millimetres.

The obstruction element may have a width of between about 0.7 millimetres and about 3 millimetres, between about 0.7 millimetres and about 2.5 millimetres, or between about 0.7 millimetres and about 2 millimetres.

The obstruction element may have a width of between about 1 millimetre and about 3 millimetres, between about 1 millimetre and about 2.5 millimetres, or between about 1 millimetre and about 2 millimetres.

The obstruction element may have a cross-sectional shape substantially the same as a cross-sectional shape of the longitudinal airflow channel. The obstruction element may have a cross-sectional area substantially the same as a cross-sectional area of the longitudinal airflow channel.

The obstruction element may have a cross-sectional area and cross-sectional shape substantially the same as a cross-sectional area and a cross-sectional shape of the longitudinal airflow channel. This may be such that the obstruction element is able to obstruct the longitudinal airflow channel to substantially prevent airflow through the longitudinal airflow channel.

The obstruction element may have a cross-sectional area greater than a cross- sectional area of the longitudinal airflow channel. This may particularly be case where the obstruction element is located at an end of the longitudinal airflow channel, for example as a coating at an upstream end face of an upstream plug of the upstream element having the longitudinal airflow channel extending therethrough. The obstruction element may have a shape and a cross-sectional area such that the obstruction element covers the entirety of an end of the longitudinal airflow channel to substantially prevent airflow through the longitudinal channel. The obstruction element may have a cross-sectional area and a cross-sectional shape substantially the same as a cross-sectional area and a cross-sectional shape of an end of an upstream plug of the upstream element having the longitudinal airflow channel extending therethrough. Where the upstream element comprises an upstream plug, the obstruction element may be located on an end face of the upstream plug, the obstruction element having a cross-sectional area and a cross-sectional shape substantially the same as a cross-sectional area and a cross-sectional shape of the end face of the upstream plug.

The obstruction element may have a length substantially the same as a length of the longitudinal airflow channel. The obstruction element may have a length less than a length of the longitudinal airflow channel.

The obstruction element may extend along substantially the entire length of the upstream element. The obstruction element may extend substantially from the upstream end of the upstream element to the downstream end of the upstream element. For example, the obstruction element may extend the entire length of an upstream plug of the upstream element. Where the obstruction element extends along substantially the entire length of the upstream element, the reduction in the resistance to draw of the upstream element from the initial state to the final state may be greater than in an upstream element where the obstruction element does not extend substantially the entire length of the upstream element. This is because, where the obstruction element extends substantially the entire length of the upstream element, the upstream element in the final state may have a substantially unobstructed longitudinal airflow channel extending substantially the entire length of the upstream element which provides a pathway with a low resistance for air to flow through.

The obstruction element may not extend the entire length of upstream element.

The obstruction element may extend along at least about 20 percent of the length of the upstream element, at least about 50 percent of the length of the upstream element, or at least about 80 percent of the length of the upstream element.

The obstruction element may extend up to the entire length of the upstream element. For example, the obstruction element may extend up to about 90 percent of the length of the upstream element, or up to about 80 percent of the length of the upstream element.

The obstruction element may extend along between about 20 percent and about 100 percent of the length of the upstream element, between about 50 percent and about 100 percent of the length of the upstream element, or between about 80 percent and about 100 percent of the length of the upstream element.

The obstruction element may extend along between about 20 percent and about 90 percent of the length of the upstream element, between about 50 percent and about 90 percent of the length of the upstream element, or between about 80 percent and about 90 percent of the length of the upstream element. The obstruction element may extend along between about 20 percent and about 80 percent of the length of the upstream element, or between about 50 percent and about 80 percent of the length of the upstream element.

The obstruction element may have a length of at least about 1 millimetre, at least about 2.5 millimetres, or at least about 4 millimetres. The obstruction element may have a length of less than or equal to about 10 millimetres, less than or equal to about 8 millimetres or less than or equal to about 6 millimetres. For example, the obstruction element may have a length of about 5 millimetres.

Where the obstruction element is in the form of a powder, the width, cross-sectional area, length, size and shape of the obstruction element may refer to the width, cross-sectional area, length, size and shape of the volume occupied by the powder, respectively.

The width, cross-sectional area, length, size and shape of the obstruction element discussed herein refer to the width, cross-sectional area, length and shape of the obstruction element when the upstream element is in the initial state, unless stated otherwise.

The upstream element may comprise a plurality of longitudinal airflow channels. The properties of the longitudinal airflow channel discussed above may be applicable to each of the plurality of longitudinal airflow channels.

The upstream element may comprise a plurality of obstruction elements. The properties of the obstruction element discussed above may be applicable to each of the plurality of obstruction elements.

The upstream element may comprise a plurality of longitudinal airflow channels and a plurality of corresponding obstruction elements. For example, the upstream element may comprise three longitudinal airflow channels and three corresponding obstruction elements.

When the upstream element is in the initial state, each of the plurality of longitudinal airflow channels may be obstructed by a corresponding obstruction element to substantially prevent airflow through each of the plurality of longitudinal airflow channels.

When the upstream element is in the final state, each of the plurality of longitudinal airflow channels may be at least partially open to allow airflow through the longitudinal airflow channel.

The upstream element may comprise an upstream plug. The longitudinal airflow channel of the upstream element may be defined within the upstream plug. The longitudinal airflow channel of the upstream element may extend through the upstream plug. The longitudinal airflow channel of the upstream element may extend from the upstream end of the upstream plug to the downstream end of the upstream plug.

The upstream plug of the upstream element may be formed from one or more of: a paper based material, such as paper and cardboard; a polymeric material, such as polylactic acid; and any other cellulose based material, such as cellulose acetate. The upstream plug of the upstream element may be a plug of cellulose acetate tow.

The upstream element may have a length of at least about 2 millimetres, at least about 3 millimetres, or at least about 4 millimetres. The upstream element may have a length of less than or equal to about 10 millimetres, less than or equal to about 8 millimetres, or less than or equal to about 6 millimetres. For example, the upstream element may have a length of about 5 millimetres.

The length of the upstream element may be selected based on a desired RTD of the upstream element in one or both of the initial state and the final state. The length of the upstream element may be selected based on a desired total length of the aerosol-generating article.

The upstream element may have a substantially circular cross-sectional shape.

The upstream element may have an external diameter of at least about 5 millimetres, about 6 millimetres, or about 7 millimetres. The upstream element may have an external diameter of less than or equal to 12 millimetres, less than or equal to about 10 millimetres, or less than or equal to about 8 millimetres. For example, the upstream element may have an external diameter of about 7.3 millimetres.

The upstream element may have an external dimeter substantially the same as an external diameter of the aerosol-generating substrate. The upstream element may have an external dimeter substantially the same as an external diameter of the aerosol-generating article.

The upstream element is located upstream of the aerosol-generating substrate. The upstream element may abut the aerosol-generating substrate. The upstream element may be located at the upstream end of the aerosol-generating article.

The aerosol-generating article may comprise one or more additional elements located upstream of the upstream element.

The aerosol-generating substrate may be in the form of a rod. As used herein with reference to the present disclosure, the term “rod” is used to denote a generally cylindrical element having a substantially circular, oval or elliptical cross-section.

The aerosol-generating substrate may comprise aerosol-generating material circumscribed by a wrapper, such as an upstream plug wrap. For example, the aerosolgenerating substrate may comprise aerosol-generating material circumscribed by a wrapper to form a rod.

The aerosol-generating substrate may have a length of at least about 8 millimetres, at least about 9 millimetres, or at least about 10 millimetres. The aerosol-generating substrate may have a length of less than or equal to about 16 millimetres, less than or equal to about 15 millimetres, or less than or equal to about 14 millimetres. For example, the aerosolgenerating substrate may have a length of about 12 millimetres. The aerosol-generating substrate may have a substantially circular cross-sectional shape.

The aerosol-generating substrate may have an external diameter of at least about 5 millimetres, about 6 millimetres, or about 7 millimetres. The aerosol-generating substrate may have an external diameter of less than or equal to 12 millimetres, less than or equal to about 10 millimetres, or less than or equal to about 8 millimetres. For example, the aerosolgenerating substrate may have an external diameter of about 7.3 millimetres.

The RTD of the aerosol-generating substrate may be at least about 4 millimetres H2O, at least about 5 millimetres H2O, or at least about 6 millimetres H2O. The RTD of the aerosolgenerating substrate may be less than or equal to about 10 millimetres H2O, less than or equal to about 9 millimetres H2O, or less than or equal to about 8 millimetres H2O.

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

The aerosol-generating substrate may comprise an aerosol former.

The aerosol former may be any suitable known compound or mixture of compounds that, in use, facilitates formation of a dense and stable aerosol. 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.

The aerosol-generating substrate may comprise at least about 5 percent, at least about 10 percent, or at least about 12 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate. The aerosol-generating substrate may comprise less than or equal to about 30 percent, less than or equal to about 25 percent, or less than or equal to about 20 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate.

The aerosol-generating substrate may comprise a plurality of shreds of tobacco material. As used herein with reference to the present disclosure, the term “shred” denotes an element having a length substantially greater than a width and a thickness thereof.

The aerosol-generating substrate may comprise a plurality of pellets or granules of tobacco material.

The aerosol-generating substrate may comprise one or more sheets of tobacco material. The one or more sheets of tobacco material may have been one or more of crimped, folded, gathered, and pleated. The tobacco material may be homogenised tobacco material. As used herein with reference to the present disclosure, the term “homogenised tobacco material” is used to describe material formed by agglomerating particulate tobacco material.

The aerosol-generating article may comprise a susceptor. As used herein with reference to the present invention, the term “susceptor” refers to a material that can convert electromagnetic energy into heat. When located within a fluctuating electromagnetic field, eddy currents induced in the susceptor cause heating of the susceptor.

The susceptor is arranged in thermal contact with the aerosol-generating substrate. Thus, when the susceptor heats up, the aerosol-generating substrate is heated by the susceptor to generate an aerosol. The susceptor may be arranged in direct physical contact with the aerosol-generating substrate.

The susceptor may be arranged within the aerosol-generating substrate.

The susceptor may be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol-generating substrate. For example, the susceptor may comprise a metal or carbon. The susceptor may comprise or consist of a ferromagnetic material, for example a ferromagnetic alloy, ferritic iron, or a ferromagnetic steel or stainless steel. A suitable susceptor may be, or comprise, aluminium.

The aerosol-generating article may comprise a downstream section located downstream of the aerosol-generating substrate. The downstream section may be located immediately downstream of the aerosol-generating substrate. The downstream section may extend between the aerosol-generating substrate and the downstream end of the aerosolgenerating article.

The aerosol-generating article may comprise one or more elements provided downstream of the aerosol-generating substrate. Where present, the one or more elements located downstream of the aerosol-generating substrate form the downstream section of the aerosol-generating article.

The one or more elements may be in an abutting end to end relationship with each other.

A length of the downstream section may be at least 20 millimetres, or at least 25 millimetres, or at least 30 millimetres. A length of the downstream section may be less than 70 millimetres, or less than 60 millimetres, or less than 50 millimetres.

The aerosol-generating article may comprise a mouthpiece element located downstream of the aerosol-generating substrate. The aerosol-generating article may comprise a downstream section comprising a mouthpiece element. The mouthpiece element may be located at the downstream end of the aerosol-generating article.

The mouthpiece element may be a mouthpiece filter element. The mouthpiece element may comprises at least one filter segment for filtering aerosol generated upon heating the aerosol-generating substrate. For example, the mouthpiece element may comprise one or more segments of a fibrous filtration material. Suitable fibrous filtration materials are known in the art. For example, the at least one mouthpiece filter segment may comprise a cellulose acetate filter segment formed of cellulose acetate tow.

Each of the at least one filter segment may be a solid plug. That is, each of the at least one filter segment may be non-tubular.

The mouthpiece element may consist of a single filter segment. The mouthpiece element may include two or more filter segments axially aligned in an abutting end to end relationship with each other.

The mouthpiece element may comprise a flavourant, which may be provided in any suitable form. For example, the mouthpiece element may comprise one or more capsules, beads or granules of a flavourant, or one or more flavour loaded threads or filaments.

Parameters or characteristics described herein in relation to the mouthpiece element as a whole may equally be applied to a filter segment of the mouthpiece element.

The mouthpiece element may have an RTD of at least about 10 millimetres H2O. The mouthpiece element may have an RTD of less than or equal to about 25 millimetres H2O, less than or equal to about 20 millimetres H2O, or less than or equal to about 15 millimetres H2O.

The mouthpiece element may have a length of 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. For example, the mouthpiece element may have a length of about 7 millimetres.

The mouthpiece element may have a substantially circular cross-sectional shape.

The mouthpiece element may have an external diameter substantially the same as an external diameter of the aerosol-generating substrate. The mouthpiece element may have an external diameter substantially the same as an external diameter of the aerosol-generating article.

The mouthpiece element may be circumscribed by an upstream 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 aerosol-generating article may comprise a mouth end cavity at the downstream end of the aerosol-generating article. The aerosol-generating article may comprise a downstream section comprising a mouth end cavity.

The mouth end cavity may be downstream of the mouthpiece element, where present.

The mouth end cavity may be defined by a hollow tubular element provided at the downstream end of the mouthpiece. Alternatively, the mouth end cavity may be defined by an outer wrapper of the mouthpiece element, wherein the outer wrapper extends in a downstream direction from the mouthpiece element.

The aerosol-generating article may comprise one or more intermediate elements between the aerosol-generating substrate and the mouthpiece element. The one or more intermediate elements may be in an abutting end to end relationship with each other.

One of the one or more intermediate elements may abut the downstream end of the aerosol-generating substrate. One of the one or more intermediate elements may abut the upstream end of the mouthpiece element. For example, where there is a single intermediate element, the single intermediate element may abut both the downstream end of the aerosolgenerating substrate and the upstream end of the mouthpiece element. For example, where there are a plurality of intermediate elements, one intermediate element may abut the downstream end of the aerosol-generating substrate and another intermediate element may abut the upstream end of the mouthpiece element.

At least one of the one or more intermediate elements may be a tubular element. The one or more intermediate elements may be one or more tubular elements.

The tubular element comprises a tubular body. The tubular body defining a cavity extending from the upstream end of the tubular body to the downstream end of the tubular body.

As used herein, the term "tubular element" is used to denote a generally cylindrical element defining a lumen or airflow passage along a longitudinal axis thereof. In particular, the term "tubular" will be used in the following with reference to a tubular element having a tubular body with a substantially cylindrical cross-section and defining at least one airflow conduit establishing an uninterrupted fluid communication between an upstream end of the tubular body and a downstream end of the tubular body. However, it will be understood that alternative geometries (for example, alternative cross-sectional shapes) of the tubular body may be possible.

In the context of the present disclosure, the tubular body of the tubular element provides an unrestricted flow channel. This means that the tubular body of the tubular element provides a negligible level of resistance to draw (RTD). As used herein with reference to the present disclosure, 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 tubular body, less than 0.4 mm H2O per 10 millimetres of length of the tubular body, or less than 0.1 mm H2O per 10 millimetres of length of the tubular body. 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. In such a case, the tubular body of the tubular element defines an empty cavity. The tubular element may comprise a folded end portion forming a first end wall at the first end of the tubular body, the first end wall delimiting an opening for airflow between the cavity of the tubular body and the exterior of the tubular element. The first end of the tubular body may be the upstream end of the tubular body. The first end wall may be referred to as the upstream end wall. The first end wall may be at the upstream end of the tubular element.

The tubular element may comprise a folded end portion forming a second end wall at the second end of the tubular body, the second end wall delimiting an opening for airflow between the cavity of the tubular body and the exterior of the tubular element. The second end of the tubular body may be the downstream end of the tubular body. The second end wall may be referred to as the downstream end wall. The second end wall may be at the downstream end of the tubular element.

The tubular element may not comprise a folded end portion.

The tubular body of the tubular element may extend from the upstream end of the tubular element to the downstream end of the tubular element. That is, the tubular body may extend the entire length of the tubular element.

The one or more intermediate elements may have a total length of at least about 10 millimetres, at least about 12 millimetres, or at least about 15 millimetres. The one or more intermediate elements 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. For example, the one or more intermediate elements may have a total length of about 21 millimetres.

Where the aerosol-generating article comprises a single intermediate element, the total length of the one or more intermediate elements is the length of the single intermediate element. Where the aerosol-generating article comprises a plurality of intermediate elements, the total length of the one or more intermediate elements is the sum of the lengths of each of the plurality of intermediate elements.

Each of the one or more intermediate elements may have a substantially circular cross- sectional shape.

Each of the one or more intermediate elements may have an external diameter substantially the same as an external diameter of the aerosol-generating substrate. Each of the one or more intermediate elements may have an external diameter substantially the same as an external diameter of the aerosol-generating article.

The one or more intermediate elements may be formed from any suitable material or combination of materials. For example, at least one of the one or more intermediate elements may be formed from one or more materials selected from the group consisting of: cellulose acetate; a paper based material such as paper or cardboard; and polymeric materials, such as low density polyethylene (LDPE). Other suitable materials include polyhydroxyalkanoate (PHA) fibres.

The aerosol-generating article may comprise a ventilation zone. The aerosolgenerating article may comprise a downstream section and a ventilation zone at a location along the downstream section. A satisfactory cooling of the stream of aerosol generated upon heating the aerosol-generating substrate and drawn through the one or more intermediate elements may be achieved by providing a ventilation zone at a location along the downstream section. A ventilation zone may provide particularly efficient cooling of the generated aerosol prior to delivery to a user. Without wishing to be bound by theory, the temperature drop caused by the admission of cooler, external air into the downstream section via the ventilation zone may have an advantageous effect on the nucleation and growth of aerosol particles.

The aerosol-generating article may comprise a tubular element at a location downstream of the aerosol-generating substrate, and a ventilation zone provided at a location along the tubular element. The ventilation zone may comprise a plurality of perforations through a tubular wall of the tubular element.

A ventilation zone may be provided at a location along the one or more intermediate elements. The ventilation zone may be provided at a location along at least one of the one or more intermediate elements. Where the one or more intermediate elements are one or more tubular elements, the ventilation zone may be provided at a location along at least one of the one or more tubular elements. Where the one or more intermediate elements are one or more tubular elements, the ventilation zone may comprise a plurality of perforations through a tubular wall of at least one of the one or more tubular elements.

The ventilation zone may comprise at least one circumferential row of perforations. The ventilation zone may comprise two circumferential rows of perforations. Each circumferential row of perforations may comprise from 8 to 30 perforations. For example, the perforations may be formed online during manufacturing of the aerosol-generating article.

The aerosol-generating article may have a total length of at least about 35 millimetres, at least about 38 millimetres, at least about 40 millimetres, or at least about 42 millimetres. The aerosol-generating article may have a total length of less than or equal to about 100 millimetres, less than or equal to about 70 millimetres, less than or equal to about 60 millimetres, or less than or equal to 50 millimetres. For example, the aerosol-generating article may have a total length of about 45 millimetres.

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

The aerosol-generating article may have an external diameter of at least about 5 millimetres, at least about 6 millimetres, or at least about 7 millimetres. The aerosolgenerating article may have an external diameter of less than or equal to about 12 millimetres, less than or equal to about 10 millimetres, or less than or equal to about 8 millimetres. For example, the aerosol-generating article may have an external diameter of about

7.3 millimetres.

The upstream element of the aerosol-generating article may be heated by the aerosolgenerating device during use of the aerosol-generating article. In particular, the obstruction element of the upstream element of the aerosol-generating article may be heated by the aerosol-generating device during use of the aerosol-generating article.

Preferably, the aerosol-generating article is heated by the aerosol-generating device indirectly. The aerosol-generating device is configured to heat the aerosol-generating substrate of the aerosol-generating device. During use of the aerosol-generating article with the aerosol-generating device, the aerosol-generating substrate of the aerosol-generating device is heated. Heat from the aerosol-generating substrate may be conducted to the upstream element such that the upstream element changes state from the initial state to the final state, for example upon melting of the obstruction element.

The aerosol-generating device may be a handheld aerosol-generating device.

The aerosol-generating device may be an electrically-operated aerosol-generating device. The aerosol-generating device may comprise a power supply and control electronics. The aerosol-generating device may comprise a battery and control electronics.

The aerosol-generating device may be configured to externally heat the aerosolgenerating substrate of the aerosol-generating article. That is, the aerosol-generating device may be configured to heat the aerosol-generating substrate of the aerosol-generating article from an exterior of the aerosol-generating substrate of the aerosol-generating article.

The aerosol-generating device may comprise a heating element, for example an external heating element. The heating element may be located about a perimeter of the cavity. The heating element may be one or both of a resistive heating element and an inductive heating element.

The aerosol-generating device may comprise a mouthpiece.

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, or embodiment, or aspect described herein.

EX1 : An aerosol-generating article comprising: an aerosol-generating substrate; an upstream element located upstream of the aerosol-generating substrate, the upstream element comprising a longitudinal airflow channel and an obstruction element for obstructing the longitudinal airflow channel, wherein the upstream element is configured to change state upon heating during use of the aerosol-generating article from: an initial state, in which the longitudinal airflow channel is obstructed by the obstruction element to substantially prevent airflow through the longitudinal airflow channel, to a final state, in which the longitudinal airflow channel is at least partially open to allow airflow through the longitudinal airflow channel.

EX2: An aerosol-generating article according to EX1 , wherein the upstream element has a lower resistance to draw in the final state than in the initial state.

EX3: An aerosol-generating article according to any preceding example, wherein the obstruction element has a lower viscosity when the upstream element is in the final state than when the upstream element is in the initial state.

EX4: An aerosol-generating article according to any preceding example, wherein the obstruction element is configured to melt during the change of state of the upstream element from the initial state to the final state.

EX5: An aerosol-generating article according to any preceding example, wherein the obstruction element has a melting point of between about 40 degrees Celsius and about 220 degrees Celsius.

EX6: An aerosol-generating article according to any preceding example, wherein the obstruction element is in form of a compressed powder when the upstream element is in the initial state.

EX7: An aerosol-generating article according to any preceding example, wherein the obstruction element comprises a wax.

EX8: An aerosol-generating article according to any preceding example, wherein the obstruction element comprises one or more of: stearin, paraffin, glycerin, Arabic gum, and a sugar.

EX9: An aerosol-generating article according to any preceding example, wherein the resistance to draw of the upstream element in the final state is less than the resistance to draw of the upstream element in the initial state by at least about 20 percent.

EX10: An aerosol-generating article according to any preceding example, wherein the resistance to draw of the upstream element in the final state is less than the resistance to draw of the upstream element in the initial state by at least about 5 millimetres H2O.

EX11 : An aerosol-generating article according to any preceding example, wherein the resistance to draw of the upstream element in the initial state is at least about 15 millimetres H₂O.

EX12: An aerosol-generating article according to any preceding example, wherein the resistance to draw of the upstream element in the final state is less than or equal to about 25 millimetres H2O. EX13: An aerosol-generating article according to any preceding example, wherein the overall resistance to draw of the aerosol-generating article when the upstream element is in the final state is less than the overall resistance to draw of the aerosol-generating article when the upstream element is in the initial state.

EX14: An aerosol-generating article according to any preceding example, wherein the overall resistance to draw of the aerosol-generating article when the upstream element is in the final state is less than the overall resistance to draw of the aerosol-generating article when the upstream element is in the initial state by at least about 5 percent.

EX15: An aerosol-generating article according to any preceding example, wherein the overall resistance to draw of the aerosol-generating article when the upstream element is in the final state is less than the overall resistance to draw of the aerosol-generating article when the upstream element is in the initial state by at least about 5 millimetres H2O,

EX16: An aerosol-generating article according to any preceding example, wherein the overall resistance to draw of the aerosol-generating article when the upstream element is in the initial state is at least about 40 millimetres H2O.

EX17: An aerosol-generating article according to any preceding example, wherein the overall resistance to draw of the aerosol-generating article when the upstream element is in the final state may be less than or equal to about 80 millimetres H2O.

EX18: An aerosol-generating article according to any preceding example, wherein a ventilation level of the aerosol-generating article when the upstream element is in the final state is less than a ventilation level of the aerosol-generating article when the upstream element is in the initial state.

EX19: An aerosol-generating article according to any preceding example, wherein a ventilation of the aerosol-generating article when the upstream element is in the final state is less than a ventilation level of the aerosol-generating article when the upstream element is in the initial state by at least about 4 percentage points.

EX20: An aerosol-generating article according to any preceding example, wherein the aerosol-generating article has a ventilation level of at least about 30 percent when the upstream element is in the initial state.

EX21 : An aerosol-generating article according to any preceding example, wherein the aerosol-generating article has a ventilation level of less than or equal to about 60 percent when the upstream element is in the final state.

EX22: An aerosol-generating article according to any preceding example, wherein the obstruction element is located substantially entirely in the longitudinal airflow channel when the upstream element is in the initial state. EX23: An aerosol-generating article according to any one of EX1 to EX21 , wherein the obstruction element is located outside of the longitudinal airflow channel when the upstream element is in the initial state.

EX24: An aerosol-generating article according to any preceding example, wherein the upstream element is located at the upstream end of the aerosol-generating article.

EX25: An aerosol-generating article according to any preceding example, wherein the longitudinal airflow channel has a width of at least about 0.5 millimetres.

EX26: An aerosol-generating article according to any preceding example, wherein the longitudinal airflow channel extends along the entire length of the upstream element.

EX27: An aerosol-generating article according to any preceding example, wherein the obstruction element has a cross-sectional shape substantially the same as a cross-sectional shape of the longitudinal airflow channel.

EX28: An aerosol-generating article according to any preceding example, wherein the obstruction element extends along the entire length of the upstream element.

EX29: An aerosol-generating article according to any preceding example, wherein the upstream element comprises a plurality of longitudinal airflow channels and a plurality of obstruction elements.

EX30: An aerosol-generating article according to any preceding example, wherein the upstream element comprises an upstream plug, and wherein the longitudinal airflow channel is defined within the upstream plug.

EX31 : An aerosol-generating article according to any preceding example, further comprising a ventilation zone located downstream of the aerosol-generating substrate.

EX32: An aerosol-generating article according to EX31 , further comprising a tubular element located downstream of the aerosol-generating substrate, and wherein the ventilation zone is provided at a location along the tubular element.

EX33: An aerosol-generating system comprising: an aerosol-generating article according to any preceding example, and an aerosol-generating device configured to heat the aerosol-generating substrate of the aerosol-generating article, wherein the aerosol-generating device comprises a housing defining a cavity configured to receive the aerosol-generating article.

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

Figure 1 shows a schematic side sectional view of an aerosol-generating article in accordance with the first aspect of the present disclosure comprising an upstream element in an initial state; Figure 2 shows a schematic side sectional view of the aerosol-generating article shown in Figure 1 following a change of state of the upstream element from the initial state to a final state;

Figure 3 shows a schematic side perspective view of the upstream element in the initial state shown in Figure 1 ;

Figure 4 shows a schematic side sectional view of part of an aerosol-generating system in accordance with the second aspect of the present disclosure comprising: an aerosolgenerating article in accordance with the first aspect of the present disclosure having an upstream element, and an aerosol-generating device;

Figure 5 shows a schematic side perspective view of the upstream element of the aerosol-generating article shown in Figure 4;

Figure 6 shows a schematic side perspective view of another upstream element for an aerosol-generating article in accordance with the first aspect of the present disclosure; and

Figure 7 shows a schematic side perspective view of another upstream element for an aerosol-generating article in accordance with the first aspect of the present disclosure.

Figure 1 shows an aerosol-generating article 100 comprising an aerosol-generating substrate 10, an upstream element 20 located upstream of the aerosol-generating substrate 10, and a downstream section 30 located downstream of the aerosol-generating substrate 10 and extending to a downstream end of the aerosol-generating article.

The downstream section 30 comprises a tubular element 32 abutting the downstream end of the aerosol-generating substrate 10. The downstream section 30 also comprises a filter element 34 located downstream of and abutting the tubular element 32. The filter element 34 comprises a plug of cellulose acetate tow.

The aerosol-generating article also comprises a ventilation zone located along the downstream section 30. In particular, the ventilation zone is located along the tubular element 32. The ventilation zone comprises a circumferential row of perforations or holes 40 extending through a tubular wall of the tubular element 32, in order to allow air flow into the internal cavity defined by the tubular element 32 from the exterior of the aerosol-generating article 100.

The upstream element 20 extends to the upstream end of the aerosol-generating article and abuts the upstream end of the aerosol-generating substrate 10.

The upstream element 20 is configured to change state upon heating during use of the aerosol-generating article 100 from an initial state (as shown in Figure 1) to a final state (as shown in Figure 2).

The upstream element 20 comprises a plug of cellulose acetate tow 22, a longitudinal airflow channel 24 defined within the plug of cellulose acetate tow 22, and an obstruction element 26. In the initial state (as shown in Figures 1 and 3), the longitudinal airflow channel 24 is obstructed by the obstruction element 26 to substantially prevent airflow through the longitudinal airflow channel 24. The obstruction element 26 is located substantially entirely within the longitudinal airflow channel 24. The obstruction element 26 has substantially the same size and shape as the longitudinal airflow channel 24. The obstruction element 26 extends from the upstream end of the upstream element 20 to the downstream end of the upstream element 20. The obstruction element 26 is a solid rod. In particular, the obstruction element 26 is a solid rod of compressed stearin powder. In some other examples, the obstruction element may be in the form of loose powder.

The longitudinal airflow channel 24 is substantially cylindrical and has a diameter of about 1.5 millimetres. Accordingly, the obstruction element 24 is also substantially cylindrical and has a diameter of about 1 .5 millimetres.

In the final state (as shown in Figure 2), the longitudinal airflow channel 24 is open to allow airflow through the longitudinal airflow channel 24.

Upon heating during use of the aerosol-generating article 100, the upstream element 22 changes state from the initial state to the final state. In particular, upon heating during use of the aerosol-generating article 100, the obstruction element 26 is heated such that it melts and flows and is absorbed by the plug of cellulose acetate tow 22. Accordingly, the longitudinal airflow channel 24 may be substantially empty when the upstream element 20 is in the final state.

As such, upon heating during use of the aerosol-generating article 100 and on a change of state of the upstream element 20 from the initial state to the final state, the resistance to draw of the upstream element 20 decreases. Upon heating during use of the aerosol-generating article 100, the overall resistance to draw of the aerosol-generating article 100 also decreases.

Upon a reduction of the resistance to draw of the upstream element 20 on a change of state of the upstream element 20 from the initial state to the final state, the ventilation level of the aerosol-generating article 100 also decreases. The aerosol-generating article 100 having a high ventilation level when the upstream element 20 is in the initial state and a lower ventilation level when the upstream element 20 is in the final state may mean that the aerosol generated during the initial few puffs by a user is cooled to a greater extent than the aerosol generating during later puffs by the user. This may be such that the aerosol delivered to a user throughout the entire user experience is at an acceptable temperature.

The upstream element 22 has a length of about 5 millimetres. The aerosol-generating substrate 10 has a length of about 12 millimetres. The tubular element 32 has a length of about 21 millimetres. The mouthpiece element 34 has a length of about 7 millimetres. Accordingly, the aerosol-generating article has a length of about 45 millimetres. The aerosol-generating article has an external diameter of about 7.3 millimetres.

Figure 4 shows part of an aerosol-generating system 1000 comprising an aerosolgenerating article 200 and an aerosol-generating device 250. In particular, Figure 4 shows a part of the aerosol-generating device 250.

In Figure 4, the aerosol-generating article 200 is inserted into a cavity 254 of the aerosol-generating device 250.

The aerosol-generating article 200 has an upstream element 120. Figure 4 shows the aerosol-generating article 200 with the upstream element 120 in an initial state.

The aerosol-generating article 200 shown in Figure 4 is of substantially similar construction to the aerosol-generating article 100 shown in Figures 1 and 2. Like reference numerals are used in Figures 1 , 2 and 4 to designate like parts.

The aerosol-generating substrate 10, tubular element 32, ventilation holes 40 and filter element 34 shown in Figure 4 are the same as the aerosol-generating substrate 10, tubular element 32, ventilation holes 40 and filter element 34 shown in Figures 1 and 2, respectively.

The aerosol-generating article 200 shown in Figure 4 differs from the aerosolgenerating article 100 shown in Figures 1 and 2 in that the longitudinal airflow channel 124 does not extend to either the upstream end or the downstream end of the upstream element 120. The longitudinal airflow channel 124 extends about 80 percent along the length of the upstream element 122.

Accordingly, when the upstream element 120 of the aerosol-generating article 200 is in the initial state, the obstruction element 122 does not extend to either the upstream end or the downstream end of the upstream element 120. Instead, the obstruction element 122 is embedded entirely within the plug of cellulose acetate tow 122. The obstruction element 126 extends about 80 percent along the length of the upstream element 122. Figure 5 shows the upstream element 122 when it is in the initial state.

The aerosol-generating device 250 comprises a housing defining a cavity 254 configured to receive the aerosol-generating article 200. The aerosol-generating device 250 comprises an external heating element 258 for resistively heating the aerosol-generating substrate 10 of the aerosol-generating article 200 during use. During use, the upstream element 120 is heated by the external heating element 258 of the aerosol-generating device 250 indirectly. During use, the external heating element 258 of the aerosol-generating device 250 heats the aerosol-generating substrate 10 of the aerosol-generating article 200, and heat from the aerosol-generating substrate 10 is conducted to the upstream element 120. The upstream element 120 is heated such that the obstruction element 122 melts.

The aerosol-generating device 250 comprises air flow inlets 256 located at the distal end of the cavity 254 such that air can be drawn through the aerosol-generating article 200 during use. Figure 6 shows an example of another upstream element 220 in an initial state. The upstream element 220 shown in Figure 6 is of substantially similar construction to the upstream element 20 shown in Figures 1 , 2 and 3. Like reference numerals are used in Figures 1 , 2, 3 and 6 to designate like parts.

The upstream element 220 shown in Figure 6 differs from the upstream element 20 shown in Figures 1 , 2 and 3 in that the upstream element 220 comprises three longitudinal airflow channels. The longitudinal airflow channels shown in Figure 6 are of substantially similar construction to the longitudinal airflow channel 24 shown in Figures 1 , 2 and 3 and also extend from the upstream end of the upstream element 220 to the downstream end of the upstream element 220.

The upstream element 220 also comprises three corresponding obstruction elements 226, each located within one of the longitudinal airflow channels.

Figure 7 shows an example of another upstream element 320 in an initial state. The upstream element 320 comprises a plurality of longitudinal airflow channels (not shown).

The upstream element 320 comprises an obstruction element 326 provided as a layer located at the upstream end of the upstream element 320. In particular, the obstruction element 326 is provided as a coating on an upstream end face of a plug of cellulose acetate tow 322 of the upstream element 320. The coating covers substantially the entirety of the upstream end face of the plug of cellulose acetate tow 322.

When the upstream element 320 is in the initial state, the obstruction element 326 substantially obstructs each of the plurality of longitudinal airflow channels to substantially prevent airflow through the upstream element 326.

On a change of state of the upstream element 320 from the initial state to the final state, at least a majority of the plurality of longitudinal airflow channels are at least partially open to allow airflow through the longitudinal airflow channels and through the upstream element. As such, the upstream element has a lower resistance to draw when the upstream element is in the final state than in the initial state.

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

Claims

CLAIMS:

1. An aerosol-generating article comprising: an aerosol-generating substrate; an upstream element located upstream of the aerosol-generating substrate, the upstream element comprising a longitudinal airflow channel and an obstruction element for obstructing the longitudinal airflow channel, wherein the upstream element is configured to change state upon heating during use of the aerosol-generating article from: an initial state, in which the longitudinal airflow channel is obstructed by the obstruction element to substantially prevent airflow through the longitudinal airflow channel, to a final state, in which the longitudinal airflow channel is at least partially open to allow airflow through the longitudinal airflow channel, wherein the upstream element has a lower resistance to draw in the final state than in the initial state.

2. An aerosol-generating article according to claim 1 , wherein during the change of state of the upstream element from the initial state to the final state, the viscosity of the obstruction element decreases.

3. An aerosol-generating article according to claim 1 or 2, wherein the obstruction element has a melting point between about 40 degrees Celsius and about 220 degrees Celsius.

4. An aerosol-generating article according to any one of claims 1 to 3, wherein the resistance to draw of the upstream element in the final state is less than the resistance to draw of the upstream element in the initial state by at least about 20 percent.

5. An aerosol-generating article according to any one of claims 1 to 4, wherein the resistance to draw of the upstream element in the final state is less than the resistance to draw of the upstream element in the final state by at least about 90 millimetres H2O.

6. An aerosol-generating article according to any one of claims 1 to 5 further comprising a ventilation zone, wherein a ventilation level of the aerosol-generating article when the upstream element is in the final state is less than a ventilation level of the aerosol-generating article when the upstream element is in the initial state.

7. An aerosol-generating article according to claim 6, wherein a ventilation level of the aerosol-generating article when the upstream element is in the final state is less than a ventilation level of the aerosol-generating article when the upstream element is in the initial state by at least about 5 percentage points.

8. An aerosol-generating article according to any one of claims 1 to 7, wherein the overall resistance to draw of the aerosol-generating article when the upstream element is in the final state is less than the overall resistance to draw of the aerosol-generating article when the upstream element is in the initial state by at least about 5 percent.

9. An aerosol-generating article according to any one of claims 1 to 8, wherein the obstruction element comprises a wax.

10. An aerosol-generating article according to any one of claims 1 to 9, wherein the obstruction element comprises one or more of: stearin, paraffin, glycerine, Arabic gum, and a sugar.

11. An aerosol-generating article according to any one of claims 1 to 10, wherein the obstruction element is located at the upstream end of the upstream element when the upstream element is in the initial state.

12. An aerosol-generating article according to any one of claims 1 to 11 , wherein the obstruction element is at least partially located in the longitudinal airflow channel when the upstream element is in the initial state.

13. An aerosol-generating article according to any one of claims 1 to 12, wherein the longitudinal airflow channel has a width of at least about 0.5 millimetres.

14. An aerosol-generating article according to any one of claims 1 to 13, wherein the upstream element comprises a plug of cellulose acetate tow, and wherein the longitudinal airflow channel of the upstream element extends through the plug of cellulose acetate tow.

15. An aerosol-generating system comprising: an aerosol-generating article according to any one of claims 1 to 14; and an aerosol-generating device configured to heat the aerosol-generating substrate of the aerosol-generating article, wherein the aerosol-generating device comprises a housing defining a cavity configured to receive the aerosol-generating article.