AEROSOL-GENERATING ARTICLE COMPRISING HOLLOW TUBULAR ELEMENT WITH CAPSULE AND VENTILATION

The present invention relates to an aerosol-generating article comprising an aerosolgenerating substrate and adapted to produce an inhalable aerosol upon heating. In particular, the present invention relates to an aerosol-generating article comprising an aerosolgenerating substrate contained within a capsule, the aerosol-generating article further comprising a ventilation zone.

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

A number of prior art documents disclose aerosol-generating devices for consuming aerosol-generating articles. Such devices include, for example, electrically heated aerosolgenerating devices in which an aerosol is generated by the transfer of heat from one or more electrical heater elements of the aerosol-generating device to the aerosol-generating substrate of a heated aerosol-generating article. For example, electrically heated aerosolgenerating devices have been proposed that comprise an internal heater blade which is adapted to be inserted into the aerosol-generating substrate.

Use of an aerosol-generating article in combination with an external heating system is also known. For example, WO 2020/115151 describes the provision of one or more heating elements arranged around the periphery of the aerosol-generating article when the aerosolgenerating article is received in a cavity of the aerosol-generating device. As an alternative, inductively heatable aerosol-generating articles comprising an aerosol-generating substrate and a susceptor arranged within the aerosol-generating substrate have been proposed by WO 2015/176898.

Certain types of aerosol-generating substrates containing nicotine and a relatively high aerosol former content are known, for example, nicotine containing gels and films. Such substrates are typically very stable during storage and advantageously provide a very consistent delivery of nicotine to the consumer upon heating. They can also advantageously generate aerosol at a lower temperature than other solid substrates. However, the use of aerosol-generating substrates of this type can also present issues. The relatively high aerosol former content increases the risk of leakage of aerosol former from the substrate during storage as well as during use. The leakage of aerosol former from the aerosol-generating article is undesirable, since it can leak into the heating chamber of the aerosol-generating device and potentially contaminate the aerosol-generating device. The leakage of aerosol former or gel composition may also be potentially unpleasant for the consumer.

It would therefore be desirable to provide a novel aerosol-generating article having an arrangement that provides improved retention of the aerosol-generating substrate within the aerosol-generating article during storage and use.

In addition, it would be desirable to provide a novel aerosol-generating article having an arrangement which maximises the generation and delivery of aerosol from an aerosolgenerating substrate.

The present disclosure relates to an aerosol-generating article for generating an inhalable aerosol upon heating. The aerosol-generating article may comprise a hollow tubular element. The aerosol-generating article may comprise a capsule mounted within the hollow tubular element. The capsule may be located at an upstream end of the hollow tubular element. The capsule may contain an aerosol-generating substrate. The hollow tubular element may comprise a ventilation zone to allow external air to enter the aerosol-generating article. The ventilation zone may be provided downstream of the downstream end of the capsule.

According to a first aspect of the present invention, there is provided an aerosolgenerating article for generating an inhalable aerosol upon heating, the article comprising a hollow tubular element and a capsule mounted within the hollow tubular element at an upstream end of the hollow tubular element. The capsule contains an aerosol-generating substrate. The hollow tubular element comprises a ventilation zone to allow external air to enter the aerosol-generating article. The ventilation zone is provided downstream of the downstream end of the capsule.

The provision of the aerosol-generating substrate contained within a capsule may advantageously provide a highly effective way to retain the aerosol-generating substrate in place within the aerosol-generating article during storage and use. The configuration of the present invention may be particularly advantageous for aerosol-generating substrates having a relatively high aerosol former content. The containment of the aerosol-generating substrate within the capsule prevents leakage of aerosol former from the aerosol-generating substrate during storage or use. In addition, in the event that the aerosol-generating substrate melts upon heating, the melted substrate can be effectively retained within the capsule. Leakage of the aerosol former or aerosol-generating substrate from the aerosol-generating article during use can therefore be substantially prevented, so that the risk of contamination of the aerosolgenerating device is advantageously minimised.

The arrangement of the capsule within the hollow tubular element is relatively simple and the amount of material required to produce the aerosol-generating article can therefore advantageously be reduced compared to existing aerosol-generating articles having a more complex structure. In particular, where aerosol-generating substrates are used that can generate aerosols at a relatively low temperature, it is possible to produce an aerosolgenerating article according to the invention within minimal filtration material downstream of the capsule.

The provision of a ventilation zone downstream of the downstream end of the capsule may allow ambient air to be drawn into the hollow tubular element. The provision of ambient air may advantageously improve aerosol generation from the aerosol-generating substrate. Without wishing to be bound by theory, the cool ambient air provided by the ventilation zone may mix with the warmer air from the capsule. This mixing may advantageously facilitate nucleation of the aerosol which may then be delivered to a user through the downstream end of the aerosol-generating article. For example, where the aerosol-generating substrate comprises nicotine and an aerosol former such as glycerine, the heating of the aerosolgenerating substrate in use may generate free-base nicotine vapour and volatile organic acid vapour. When these vapours are cooled by the ambient air, acid droplets are formed which combine with the volatile free-base nicotine. In this way, the nicotine may be delivered as a nicotine salt. In addition, the nicotine salt may bind to larger condensed glycerine droplets to make the nicotine more readily adsorbed. Accordingly, the cooling effect of the ventilation zone may advantageously improve the aerosol generation and delivery of the aerosolgenerating article.

In use, the aerosol-generating article of the present invention may be used with a corresponding aerosol-generating device. The aerosol-generating article may be inserted into the aerosol-generating device which may heat at least the portion of the aerosol-generating article containing the capsule. This may heat the aerosol-generating substrate generating vapours. These vapours may exit the capsule and mix with ambient air provided by the ventilation zone at which point the vapours may condense and nucleate to form an aerosol which can be delivered to a user.

Additional components may or may not be provided downstream of the ventilation zone, as discussed in more detail below. The capsule may include at least one air inlet and at least one air outlet, as discussed in more detail below.

The term “aerosol-generating article” is used herein to denote an article wherein an aerosol-generating substrate is heated to produce and deliver an inhalable aerosol to a consumer. As used herein, the term “aerosol-generating substrate” denotes a substrate capable of releasing volatile compounds upon heating to generate an aerosol.

As used herein, the term “aerosol-generating device” refers to a device comprising a heater element that interacts with the aerosol-generating substrate of the aerosol-generating article to generate an aerosol.

As used herein, the term “longitudinal” refers to the direction corresponding to the main longitudinal axis of the aerosol-generating article or aerosol-generating device, which extends between the upstream and downstream ends of the aerosol-generating article or aerosolgenerating device. As used herein, the terms “upstream” and “downstream” describe the relative positions of elements, or portions of elements, of the aerosol-generating article or aerosol-generating device in relation to the direction in which the aerosol is transported through the aerosol-generating article or aerosol-generating device during use.

During use, air is drawn through the aerosol-generating article in the longitudinal direction. The term “transverse” or “radial” refers to the direction that is perpendicular to the longitudinal axis. Any reference to the “cross-section” of the aerosol-generating article or a component of the aerosol-generating article refers to the transverse cross-section unless stated otherwise.

The term “length” denotes the dimension of a component of the aerosol-generating article in the longitudinal direction. For example, it may be used to denote the dimension of the rod or of the elongate tubular elements in the longitudinal direction.

As used herein, the term "hollow tubular element" is used to denote a generally elongate 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 substantially cylindrical cross-section and defining at least one airflow conduit establishing an uninterrupted fluid communication between an upstream end of the tubular element and a downstream end of the tubular element. However, it will be understood that alternative geometries (for example, alternative cross-sectional shapes) of the tubular element may be possible.

In the context of the present invention a hollow tubular element provides an unrestricted flow channel. This means that the hollow tubular element provides a negligible level of resistance to draw (RTD). The term “negligible level of RTD” is used to describe an RTD of less than 1 mm H2O per 10 millimetres of length of the hollow tubular element, preferably less than 0.4 mm H2O per 10 millimetres of length of the hollow tubular element, more preferably less than 0.1 mm H2O per 10 millimetres of length of the hollow tubular element.

The hollow tubular element has the capsule containing the aerosol-generating substrate mounted at the upstream end, as described above. Further, the hollow tubular element defines an empty cavity downstream of the capsule, which extends along a part or all of the length of the hollow tubular element. In some embodiments, the empty cavity extends from the capsule all of the way to the downstream end of the aerosol-generating article. In such embodiments, the aerosol-generating article can therefore be formed with only two elements: the capsule and the hollow tubular element. Alternatively, one or more filter segments may be provided within the hollow tubular element, at the downstream end thereof, as described in more detail below.

The empty cavity defined within the hollow tubular element downstream of the capsule preferably has a length of at least 10 millimetres, more preferably at least 12 millimetres and more preferably at least 14 millimetres. The length of the empty cavity may be up to 40 millimetres, or up to 30 millimetres, or up to 25 millimetres. For example, the empty cavity may have a length of between 10 millimetres and 40 millimetres, or between 12 millimetres and 30 millimetres, or between 14 millimetres and 25 millimetres.

The hollow tubular element preferably has a total length of at least 25 millimetres, more preferably at least 28 millimetres, more preferably at least 30 millimetres, more preferably at least 32 millimetres, more preferably at least 34 millimetres. The length of the hollow tubular element may be less than 50 millimetres, or less than 48 millimetres, or less than 45 millimetres, or less than 42 millimetres or less than 40 millimetres. For example, the total length of the hollow tubular element may be between 25 millimetres and 50 millimetres, or between 28 millimetres and 48 millimetres, or between 30 millimetres and 45 millimetres, or between 32 millimetres and 42 millimetres, or between 34 millimetres and 40 millimetres.

The hollow tubular element may have an outer diameter of between 5 millimetres and 12 millimetres, for example of between 5 millimetres and 10 millimetres or of between 6 millimetres and 8 millimetres. In a preferred embodiment, the hollow tubular element has an external diameter of 7.2 millimetres plus or minus 10 percent.

The internal diameter of the hollow tubular element is preferably constant along the length of the hollow tubular element. The lumen or cavity of the hollow tubular segment may have any cross sectional shape. The lumen of the hollow tubular segment may have a circular cross sectional shape.

Preferably, the internal diameter of the hollow tubular element is at least 5 millimetres, more preferably at least 5.5 millimetres, more preferably at least 6 millimetres, more preferably at least 6.5 millimetres. The internal diameter of the hollow tubular element is preferably less than 9 millimetres, more preferably less than 8.5 millimetres, more preferably less than 8 millimetres, more preferably less than 7.5 millimetres. For example, the internal diameter may be between 5 millimetres and 9 millimetres, or between 5.5 millimetres and 8.5 millimetres, or between 6 millimetres and 6 millimetres, or between 6.5 millimetres and 7.5 millimetres. The internal diameter may be around 7 millimetres.

The hollow tubular element preferably has a wall thickness of at least 100 micrometres, more preferably at least 150 micrometres, more preferably at least 200 micrometres, more preferably at least 250 micrometres, more preferably at least 500 micrometres. The wall thickness of the hollow tubular element may be less than 2 millimetres, preferably less than 1.5 millimetres and even more preferably less than 1.25 mm. The wall thickness of the hollow tubular element may be less than 1 millimetre. For example, the wall thickness of the hollow tubular element may be between 100 micrometres and 2 millimetres, or between 150 micrometres and 1.5 millimetres, or between 200 micrometres and 1.25 millimetres, or between 250 micrometres and 1 millimetre, or between 500 micrometres and 1 millimetre.

The hollow tubular segment may comprise a paper-based material. The hollow tubular segment may comprise at least one layer of paper. The paper may be very rigid paper. The paper may be crimped paper, such as crimped heat resistant paper or crimped parchment paper. Advantageously, a crimped paper may form one or more airflow channels extending around the outside of the capsule. The one or more airflow channels may be particularly advantageous in embodiments in which the capsule comprises at least one of an air inlet and an air outlet on a cylindrical wall of the capsule.

Preferably, the hollow tubular element is formed from cardboard. The hollow tubular element may be a cardboard tube. Advantageously, cardboard is a cost-effective material that provides a balance between being deformable in order to provide ease of insertion of the article into an aerosol-generating device and being sufficiently stiff to provide suitable engagement of the article with the interior of the device. A cardboard tube may therefore provide suitable resistance to deformation or compression during use.

The hollow tubular segment may be a paper tube. The hollow tubular segment may be a tube formed from spirally wound paper. The hollow tubular segment may be formed from a plurality of layers of the paper. The paper may have a basis weight of at least about 50 grams per square meter, at least about 60 grams per square meter, at least about 70 grams per square meter, or at least about 90 grams per square meter.

The hollow tubular segment may comprise a polymeric material. For example, the hollow tubular segment may comprise a polymeric film. The polymeric film may comprise a cellulosic film. The hollow tubular segment may comprise low density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibres. The hollow tube may comprise cellulose acetate tow.

Where the hollow tubular segment comprises cellulose acetate tow, the cellulose acetate tow may have a denier per filament of between about 2 and about 4 and a total denier of between about 25 and about 40. The capsule may be mounted within the hollow tubular element such that a portion of the capsule extends from the upstream end of the hollow tubular element, whereby the at least one capsule air inlet is positioned outside of the hollow tubular element. Preferably, at least 20 percent of the length of the capsule protrudes from the hollow tubular element, more preferably at least 30 percent of the length of the capsule. Preferably, no more than 50 percent of the length of the capsule protrudes from the hollow tubular element. The majority of the capsule is therefore within the hollow tubular element such that the capsule can be securely retained in place. In such embodiments, the hollow tubular element may comprise at least one stop such as a flange or protrusion extending inwards from the internal surface at the downstream end of the capsule, to prevent the capsule from being pushed downstream further into the hollow tubular element. For example, the hollow tubular element may comprise an annular flange extending from the internal surface. The provision of the at least one stop is described in more detail below.

The ventilation zone may comprise at least one ventilation perforation.

The at least one ventilation perforation may advantageously allow ambient air to enter the hollow tubular element to improve aerosol generation as described above.

The ventilation zone may comprise a plurality of ventilation perforations through the hollow tubular element.

The provision of a plurality of ventilation perforations may advantageously allow more ambient air to enter the hollow tubular element. In addition, the provision of a plurality of perforations may provide more even distribution of ambient air into the hollow tubular element. This may advantageously further improve the generation of aerosol.

The ventilation zone may comprise at least 2 ventilation perforations. For example, the ventilation zone may comprise at least 2, at least 3, at least 5, or at least 10 ventilation perforations through the hollow tubular element.

The provision of a greater number of ventilation perforations than this may advantageously improve the generation of aerosol.

The ventilation zone may comprise no more than 35 ventilation perforations. For example, the ventilation zone may comprise no more than 30, no more than 25, no more than 20, or no more than 15 ventilation perforations through the hollow tubular element.

This limit to the number of ventilation perforations may advantageously prevent the hollow tubular element from being weakened by the ventilation zone. This may also advantageously prevent the resistance to draw being reduced to an unacceptable level.

The ventilation zone may comprise between 2 ventilation perforations and 35 ventilation perforations. For example, the ventilation zone may comprise between 3 ventilation perforations and 30 ventilation perforations, between 5 ventilation perforations and 25 ventilation perforations, between 5 ventilation perforations and 20 ventilation perforations, or between 10 ventilation perforations and 15 ventilation perforations. The ventilation zone may comprise between 5 ventilation perforations and 15 ventilation perforations.

The plurality of ventilation perforations may comprise at least one perforation having a width of no more than 200 micrometres.

For example, the plurality of ventilation perforations may comprise at least one perforation having a width of no more than 175 micrometres, no more than 150 micrometres, no more than 125 micrometres, or no more than 120 micrometres.

The plurality of ventilation perforations may comprise at least one perforation having a width of no more than 2 millimetres. For example, the plurality of ventilation perforations may comprise at least one perforation having a width of no more than 1.5 millimetres, no more than 1 millimetre, no more than 500 micrometres, or no more than 250 micrometres.

The plurality of ventilation perforations may comprise at least one perforation having a width of at least 50 micrometres. For example, the plurality of ventilation perforations may comprise at least one perforation having a width of at least 65 micrometres, at least 80 micrometres, at least 90 micrometres, or at least 100 micrometres.

The plurality of ventilation perforations may comprise at least one perforation having a length of at least 400 micrometres. For example, the plurality of ventilation perforations may comprise at least one perforation having a length of at least 425 micrometres, at least 450 micrometres, at least 475 micrometres, or at least 500 micrometres.

The plurality of ventilation perforations may comprise at least one perforation having a length of no more than 1 millimetres. For example, the plurality of ventilation perforations may comprise at least one perforation having a length of no more than 950 micrometres, no more than 900 micrometres, no more than 850 micrometres, or no more than 800 micrometres.

Where the ventilation zone comprises a plurality of ventilation perforations, each of the plurality of ventilation perforations may have substantially the same dimensions. This may advantageously ensure an even supply of ambient air to the hollow tubular element.

The plurality of ventilation perforations may form a line of perforations which circumscribes the hollow tubular element.

The ventilation zone may comprise a porous portion of the hollow tubular element.

This may prevent any perforations from being visible on the outer surface of the aerosolgenerating article. This may advantageously improve the appearance of the aerosolgenerating article. In addition, the provision of a porous portion of the hollow tubular element may advantageously improve the strength of the hollow tubular element since it may remove the need for ventilation perforations. The porous portion of the hollow tubular element forming the ventilation zone may have a basis weight which is lower than that of a portion of the hollow tubular element which does not form part of the ventilation zone.

The upstream end of the ventilation zone may be located at least 20 millimetres from the upstream end of the aerosol-generating article.

For example, the upstream end of the ventilation zone may be located at least about 25 millimetres from the upstream end of the aerosol-generating article.

Locating the ventilation zone as outlined above may ensure that the ventilation zone is located outside the corresponding aerosol-generating device when the aerosol-generating article is being used with an aerosol-generating device. This may advantageously ensure that the ventilation zone is not occluded by the aerosol-generating device when is use and may also ensure that the ambient air entering the aerosol-generating device through the ventilation zone is not heated by the heater of the aerosol-generating device.

The upstream end of the ventilation zone may be located no more than 37 millimetres from the upstream end of the aerosol-generating article.

For example, the upstream end of the ventilation zone may be located no more than about 30 millimetres from the upstream end of the aerosol-generating article.

Locating the ventilation zone as outlined above may advantageously prevent the ventilation zone being occluded by a user’s mouth or lips when the aerosol-generating article is in use.

The upstream end of the ventilation zone may be located between about 20 millimetres and about 37 millimetres, or between about 25 millimetres and about 30 millimetres from the upstream end of the aerosol-generating article. The upstream end of the ventilation zone may be located about 27 millimetres from the upstream end of the aerosol-generating article.

The upstream end of ventilation zone may be located no more than 10 millimetres from the downstream end of the capsule.

For example, the upstream end of the ventilation zone may be located no more than 8 millimetres, no more than 5 millimetres, no more than 3 millimetres, or no more than 1 millimetre from the from the downstream end of the capsule.

The upstream end of the ventilation zone may be longitudinally aligned with the downstream end of the capsule.

Locating the ventilation zone close to the downstream end of the capsule may advantageously provide for a rapid and sharp temperature drop as soon as the vapour leaves the capsule. This may advantageously facilitate efficient nucleation of the aerosol from the vapour. The ventilation level of the aerosol-generating article provided by the ventilation zone may be at least 20 percent.

The aerosol-generating article may typically have a ventilation level of at least about 10 percent, preferably at least about 20 percent.

In preferred embodiments, the aerosol-generating article has a ventilation level of at least about 20 percent or 25 percent or 30 percent. More preferably, the aerosol-generating article has a ventilation level of at least about 35 percent.

The aerosol-generating article preferably has a ventilation level of less than about 80 percent. More preferably, the aerosol-generating article has a ventilation level of less than about 60 percent or less than about 50 percent.

The aerosol-generating article may typically have a ventilation level of between about 10 percent and about 80 percent.

In some embodiments, the aerosol-generating article has a ventilation level from about 20 percent to about 80 percent, preferably from about 20 percent to about 60 percent, more preferably from about 20 percent to about 50 percent. In other embodiments, the aerosolgenerating article has a ventilation level from about 25 percent to about 80 percent, preferably from about 25 percent to about 60 percent, more preferably from about 25 percent to about 50 percent. In further embodiments, the aerosol-generating article has a ventilation level from about 30 percent to about 80 percent, preferably from about 30 percent to about 60 percent, more preferably from about 30 percent to about 50 percent.

In particularly preferred embodiments, the aerosol-generating article has a ventilation level from about 40 percent to about 50 percent. In some particularly preferred embodiments, the aerosol-generating article has a ventilation level of about 45 percent.

The aerosol-generating article may further comprise at least one stop protruding from the inner surface of the hollow tubular element to prevent the capsule from moving further downstream than the at least one stop.

The provision of the at least one stop may advantageously help to retain the capsule in place within the hollow tubular element. In particular, the at least one stop may advantageously prevent the capsule from moving too far downstream where it may occlude the ventilation zone preventing ambient air entering the hollow tubular element.

The at least one stop may be located upstream of the ventilation zone.

Locating the at least one stop upstream of the ventilation zone may further advantageously prevent the capsule from moving too far downstream and occluding the ventilation zone.

The at least one stop may be any type of stop. The at least one stop may restrict the inner diameter of the hollow tubular element at a point. The inner diameter of the hollow tubular element at the at least one stop may be less than the outer diameter of the capsule thereby preventing the capsule from moving any further downstream than the at least one stop.

The at least one stop may comprise an embossed potion of the hollow tubular element extending into the interior of the hollow tubular element.

The at least one stop may comprise a thicker portion of the hollow tubular element which reduces the inner diameter of the hollow tubular element to prevent the capsule from moving any further downstream than the thicker portion.

The at least one stop may comprise a flange within and attached to the hollow tubular element which prevents the capsule from moving further downstream.

The hollow tubular element may comprise at least one flap, the at least one flap formed from a portion of the hollow tubular element which is partially detached from the remainder of the hollow tubular element forming a gap between the flap and the remainder of the hollow tubular element, the flap remaining attached to the remainder of the hollow tubular element along an attachment line, wherein the flap extends into the interior or the hollow tubular element such that: the at least one stop comprises the at least flap, and the at least one ventilation perforation comprises the gap between the flap and the remainder of the hollow tubular element.

In other words, the at least one ventilation perforation may be formed by piercing a hole in the hollow tubular element from the outside of the hollow tubular element to form a hole. In doing so, a portion of the hollow tubular element is pushed into the interior of the hollow tubular element. The piercing is performed such that the portion of the hollow tubular element remains attached to the hollow tubular element along an attachment line, forming a flap. This flap extending into the interior of the hollow tubular element is the at least one stop.

The formation of the at least one stop in this way may advantageously allow both the ventilation zone and the at least one stop to be formed during a single process thereby simplifying manufacture of the aerosol-generating article.

The attachment line may be located at the upstream end of the flap. Locating the attachment line at the upstream end of the flap may advantageously mean that the flap, acting as the at least one stop, is located upstream of the ventilation perforation formed by the manufacture of the flap. As described above, this may advantageously prevent the capsule from occluding the ventilation perforation which would disadvantageously prevent ambient air from entering the hollow tubular element.

The capsule may comprise a capsule outer wall which defines the internal cavity that contains the aerosol-generating substrate. The capsule outer wall may be formed of any suitable material. Preferably, the capsule outer wall is formed of an air impermeable material, most preferably an air impermeable polymeric material. This ensures that air does not pass through the capsule outer wall, other than in the holes provided specifically for airflow during use. The airflow through the capsule during use can therefore be effectively controlled.

The capsule outer wall may comprise a polymeric material or a cellulose based material. For example, the capsule outer wall may be made of one or more polymers that are compatible with nicotine, including medical grade polymers such as ALTUGLAS® Medical Resins Polymethlymethacrylate (PMMA) , Chevron Phillips K- Resin® Styrene-butadiene copolymer (SBC) , Arkema special performance polymers Pebax®, Rilsan®, and Rilsan® Clear, DOW (Health+™) Low-Density Polyethylene (LDPE) , DOW™ LDPE 91003, DOW™ LDPE 91020 (MFI 2.0; density 923), ExxonMobil™ Polypropylene (PP) PP1013H1 , PP1014H1 and PP9074MED, Trinseo CALIBRE™ Polycarbonate (PC) 2060-SERIES.

The capsule outer wall may alternatively be formed from one or more materials selected from: polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), gelatin and hydroxypropyl methyl cellulose (HPMC).

In embodiments in which it is intended for the capsule outer wall to be pierced by a heating element or piercing element in the aerosol-generating device, as described below, the capsule outer wall should be formed of a pierceable or frangible material. The upstream end wall of the capsule may optionally comprise one or more lines or areas of weakness, which are positioned in order to facilitate the insertion of a heating element through the capsule outer wall during use.

The capsule is preferably capsule shaped, in the form of a sphero-cylinder, with a cylindrical portion defined by a cylindrical wall and rounded, hemispherical end walls at each end of the cylindrical portion. This type of capsule is commonly used in the pharmaceutical industry. Alternatively, the capsule may be spherical, or ovoid.

Preferably, the capsule is a two part capsule, with two separate parts that fit together to close the capsule and retain the contents. The two separate parts may fit together by means of a friction fit, without adhesive. Alternatively, an adhesive may be used to seal the two parts together.

Preferably, the capsule comprises a first part and a second part, wherein the second part has a smaller diameter than the first part such that an end of the second part can be inserted into an open end of the first part in order to close the capsule.

In such embodiments, the outer diameters of the first part and the second part of the capsule may be adapted such that only the second part of the capsule can be received within the hollow tubular element. The outer diameter of the first part of the capsule is adapted to be larger than the inner diameter of the hollow tubular element so that the first part of the capsule cannot be received within the hollow tubular element and remains outside of the hollow tubular element Preferably, the second part of the capsule is retained within the hollow tubular element by means of a friction fit.

Alternatively, the capsule may be fully inserted into the hollow tubular element and the outer diameters of the first part and the second part of the capsule may be adapted such that the outer diameter of the second part is smaller than the internal diameter of the hollow tubular element. This provides a space between the second part of the capsule and the wall of the hollow tubular element to enable airflow around the second part of the capsule. Such an arrangement may be beneficial in embodiments in which it is desired to position air outlets on the cylindrical wall of the capsule, as described below.

The internal cavity of the capsule has a volume of at least 250 cubic millimetres, corresponding to 0.25 millimetres. This corresponds to the internal volume of the capsule, or the capacity. Preferably, the internal cavity of the capsule has a volume of at least 400 cubic millimetres (0.4 millilitres), more preferably at least 500 cubic millimetres (0.5 millilitres), more preferably at least 600 cubic millimetres (0.6 millilitres). The internal cavity of the capsule may be less than 2000 cubic millimetres (2 millilitres), or less than 1500 cubic millimetres (1.5 millilitres) or less than 1000 cubic millimetres (1 millilitre). For example, standard capsule sizes 000, 00, 0, 0, 1 , 2 and 3 may be suitable.

The capsule preferably has a length of at least 10 millimetres, more preferably at least 12 millimetres, more preferably at least 15 millimetres, more preferably at least 18 millimetres. The length of the capsule is preferably less than 30 millimetres, more preferably less than 28 millimetres, more preferably less than 25 millimetres. For example, the capsule length may be between 10 millimetres and 30 millimetres, or between 12 millimetres and 28 millimetres, or between 15 millimetres and 25 millimetres, or between 18 millimetres and 25 millimetres. The capsule length may be around 20 millimetres.

The capsule preferably has a maximum diameter of at least 5 millimetres, more preferably at least 5.5 millimetres, more preferably at least 6 millimetres, more preferably at least 6.5 millimetres. The maximum diameter of the capsule is preferably less than 9 millimetres, more preferably less than 8.5 millimetres, more preferably less than 8 millimetres, more preferably less than 7.5 millimetres. For example, the capsule maximum diameter may be between 5 millimetres and 9 millimetres, or between 5.5 millimetres and 8.5 millimetres, or between 6 millimetres and 6 millimetres, or between 6.5 millimetres and 7.5 millimetres. The capsule maximum diameter may be around 7 millimetres. The external diameter of the capsule may be approximately the same as the inner diameter of the hollow tubular element.

In this way, air is substantially prevented from passing from the upstream end of the hollow tubular element to the downstream end of the hollow tubular element without passing through the capsule.

Without wishing to be bound by theory, it is anticipated that the airflow through the aerosol-generating article will significantly slow down once the air exits the capsule through the at least one capsule air outlet and enters the interior of the hollow tubular element. This is because the diameter of the hollow tubular element is greater than the diameter of the at least one capsule air outlet. This slowing down of the airflow also results is a pressure decrease which may additionally facilitate desirable nucleation of the aerosol. In addition, the slowing down of the airflow may also improve the cooling of the airflow by the ambient air entering through the ventilation zone. This may further advantageously facilitate aerosol generation.

The internal cavity of the capsule preferably contains at least 50 milligrams of the solid aerosol-generating substrate, more preferably at least 100 milligrams of the solid aerosolgenerating substrate, more preferably at least 150 milligrams of the solid aerosol-generating substrate. The internal cavity may contain up to 1000 milligrams of the solid aerosolgenerating substrate, or up to 750 milligrams of the solid aerosol-generating substrate, or up to 500 milligrams of the solid aerosol-generating substrate, or up to 250 milligrams of the solid aerosol-generating substrate. For example, the internal cavity of the capsule may contain between 50 milligrams and 1000 milligrams of the solid aerosol-generating substrate, or between 100 milligrams and 750 milligrams of the solid aerosol-generating substrate, or between 150 milligrams and 500 milligrams of the solid aerosol-generating substrate, or between 150 milligrams and 250 milligrams of the solid aerosol-generating substrate.

According to the invention, the density of the solid aerosol-generating substrate within the capsule corresponds to at least 0.1 milligrams per cubic millimetre of the internal cavity. This corresponds to the total weight of the solid aerosol-generating substrate, divided by the total volume of the internal cavity. Preferably, the density of the solid aerosol-generating substrate within the capsule corresponds to at least 0.12 milligrams per cubic millimetre of the internal cavity, more preferably at least 0.15 milligrams per cubic millimetre of the internal cavity, more preferably at least 0.18 milligrams per cubic millimetre of the internal cavity, more preferably at least 0.2 milligrams per cubic millimetre more preferably at least 0.22 milligrams per cubic millimetre, more preferably at least 0.25 milligrams per cubic millimetre, more preferably at least 0.28 milligrams per cubic millimetre, more preferably at least 0.3 milligrams per cubic millimetre, more preferably at least 0.32 milligrams per cubic millimetre, more preferably at least 0.35 milligrams per cubic millimetre, more preferably at least 0.38 milligrams per cubic millimetre, more preferably at least 0.4 milligrams per cubic millimetre. Preferably, the density of the solid aerosol-generating substrate within the capsule corresponds to less than 2 milligrams per cubic millimetre of the internal cavity, more preferably less than 1.9 milligrams per cubic millimetre, more preferably less than 1.8 milligrams per cubic millimetre, more preferably less than 1.7 milligrams per cubic millimetre, more preferably less than 1.6 milligrams per cubic millimetre, more preferably less than 1 .5 milligrams per cubic millimetre, more preferably less than 1.4 milligrams per cubic millimetre, more preferably less than 1.3 milligrams per cubic millimetre, more preferably less than 1.2 milligrams per cubic millimetre, more preferably less than 1.1 milligrams per cubic millimetre, more preferably less than 1 milligram per cubic millimetre of the internal cavity. For example, the density of the solid aerosol-generating substrate within the capsule may correspond to between 0.1 milligrams per cubic millimetre and 2 milligrams per cubic millimetre of the internal cavity, or between 0.12 milligrams per cubic millimetre and 1.9 milligrams per cubic millimetre of the internal cavity, or between 0.15 milligrams per cubic millimetre and 1.8 milligrams per cubic millimetre of the internal cavity, or between 0.18 milligrams per cubic millimetre and 1.7 milligrams per cubic millimetre of the internal cavity, or between 0.2 milligrams per cubic millimetre and 1.6 milligrams per cubic millimetre of the internal cavity, or between 0.22 milligrams per cubic millimetre and 1.5 milligrams per cubic millimetre of the internal cavity, or between 0.25 milligrams per cubic millimetre and 1 .4 milligrams per cubic millimetre of the internal cavity, or between 0.28 milligrams per cubic millimetre and 1.3 milligrams per cubic millimetre of the internal cavity, or between 0.3 milligrams per cubic millimetre and 1.2 milligrams per cubic millimetre of the internal cavity, or between 0.32 milligrams per cubic millimetre and 1.1 milligrams per cubic millimetre of the internal cavity, or between 0.35 milligrams per cubic millimetre and 1 milligrams per cubic millimetre of the internal cavity, or between 0.38 milligrams per cubic millimetre and 1 milligrams per cubic millimetre of the internal cavity, or between 0.4 milligrams per cubic millimetre and 1 milligrams per cubic millimetre of the internal cavity.

The percentage fill of the capsule by the solid aerosol-generating substrate is preferably at least 50 percent, more preferably at least 60 percent, more preferably at least 70 percent. The percentage fill is preferably less than 90 percent. The percentage fill corresponds to the percentage of the internal cavity of the capsule that is occupied by the solid aerosol-generating substrate. It may be advantageous to retain some empty space within the internal cavity to allow for air flow through the internal cavity and for the solid aerosol-generating substrate to be heated evenly. The capsule may be adapted such that one or more airflow pathways is provided through the capsule during heating. This enables the aerosol generated from the aerosol-generating substrate to be drawn through the aerosol-generating article and delivered to the consumer. The capsule may be initially sealed and airtight but adapted such that airflow pathways are created when the aerosol-generating article is inserted into an aerosol-generating device, for example, through the insertion of an internal heating element or by means of a piercing element which pierces the capsule outer wall.

Alternatively and preferably, the capsule comprises at least one capsule air inlet and at least one capsule air outlet in the capsule outer wall. The at least one capsule air inlet and the at least one capsule air outlet define one or more airflow pathways through the internal cavity of the capsule. The at least one capsule air outlet is provided downstream of the at least one capsule air inlet.

The capsule may comprise at least one capsule air inlet located at the upstream end of the capsule, and at least one capsule air outlet located at the downstream end of the capsule.

The capsule may comprise a plurality of capsule air inlets. For example, the capsule may comprise between 2 and 6 capsule air inlets.

The capsule may comprise a plurality of capsule air outlets. For example, the capsule may comprise between 2 and 6 capsule air outlets. The number of capsule air outlets may be the same as the number of capsule air inlets, or different. It may be advantageous to provide a greater number of capsule air outlets than capsule air inlets, since the capsule air outlets need to allow the aerosol generated within the capsule to pass out of the capsule into the hollow tubular element.

The number and size of the capsule air inlets and capsule air outlets may be adjusted in order to control the airflow through the capsule and also the resistance to draw (RTD) of the aerosol-generating article. In certain embodiments, the capsule will provide the main source of RTD within the article and the overall RTD of the aerosol-generating article is therefore likely to be very dependent on the RTD of the capsule.

Each capsule air inlet and capsule air outlet is preferably in the form of a hole through the capsule outer wall. Preferably, each hole is spherical, although other shapes may also be suitable. The diameter of each hole should be sufficiently large that the hole cannot easily be blocked, for example, by dust. However, the diameter of each hole should also be adapted depending on the form and nature of the solid aerosol-generating substrate, so that the solid aerosol-generating substrate is not lost from the internal cavity, through the hole.

Preferably, each hole forming an air inlet or air outlet has a diameter of at least 0.2 millimetres, more preferably at least 0.25 millimetres, more preferably at least 0.3 millimetres, more preferably at least 0.35 millimetres, more preferably at least 0.4 millimetres, more preferably at least 0.5 millimetres. The diameter of each hole may be less than 2 millimetres, or less than 1.8 millimetres, or less than 1.6 millimetres, or less than 1.4 millimetres, or less than 1.2 millimetres, or less than 1 millimetre, or less than 0.9 millimetres, or less than 0.8 millimetres. For example, the diameter of each hole may be between 0.2 millimetres and 2 millimetres, or between 0.25 millimetres and 1.8 millimetres, or between 0.3 millimetres and 1.6 millimetres, or between 0.35 millimetres and 1.4 millimetres, or between 0.4 millimetres and 1.2 millimetres, or between 0.45 millimetres and 1 millimetres, or between 0.5 millimetres and 0.9 millimetres or between 0.5 millimetres and 0.8 millimetres.

Where a plurality of capsule air inlets or capsule air outlets is provided, the respective holes should be spaced apart sufficiently so that the presence of the holes does not adversely impact the structural integrity of the capsule. For example, the holes are preferably spaced at least 1 millimetre apart from each other.

The at least one capsule air outlet is preferably at least 5 millimetres downstream of the at least one air inlet, more preferably at least 8 millimetres downstream of the at least one air inlet and more preferably at least 10 millimetres downstream of the at least one air inlet. This spacing enables the length of the airflow pathway through the capsule to be maximised.

The at least one capsule air outlet is preferably positioned at the downstream end of the capsule. Where the capsule has a conventional capsule shape, with an elongate cylindrical body and rounded end walls, the at least one capsule air outlet is preferably provided on the downstream end wall.

The at least one capsule air inlet may be positioned at the upstream end of the capsule. For example, where the capsule has a conventional capsule shape as described above, the at least one capsule air inlet may be provided on the upstream end wall. However, in certain embodiments it may be advantageous to position the at least one capsule air inlet a certain distance downstream of the upstream end. For example, the at least one capsule air inlet may be provided at least 2 millimetres downstream of the upstream end of the capsule, or at least 3 millimetres downstream of the upstream end of the capsule, or at least 4 millimetres downstream of the upstream end of the capsule, or at least 5 millimetres downstream of the upstream end of the capsule. Where a plurality of capsule air inlets are provided, all of the air inlets should be provided at least this distance from the upstream end, even when the position of the capsule air inlets along the length of the capsule varies.

In preferred embodiments, the capsule comprises a cylindrical wall and rounded end walls at the upstream and downstream ends of the cylindrical wall (as in a conventional capsule shape) and the at least one capsule air inlet may advantageously be provided in the cylindrical wall, downstream of the upstream end wall. This positioning of the at least one capsule air inlet away from the upstream end of the capsule may be particularly beneficial when the solid aerosol-generating substrate is in the form of a gel composition or any other type of substrate that melts or becomes more viscous upon heating. By the at least one capsule air inlet away from the upstream end of the cavity, where the melted substrate may collect, this ensures that the risk of the aerosol-generating substrate leaking from the capsule is minimised. The risk of blockage of the capsule air inlets by the aerosol-generating substrate is also reduced.

The at least one capsule air outlet may comprise a plurality of air outlets located at the downstream end of the capsule, the plurality of air outlets being arranged on the circumference of a circle centred on the longitudinal axis of the capsule, the circle having a diameter less than the diameter of the aerosol-generating article.

The plurality of capsule air outlets may be arranged on the circle such that each of the capsule air outlets radially overlaps with at least a portion of a ventilation perforation.

As used herein, the term “radially overlap” means that the plurality of capsule air outlets and the plurality of ventilation perforations are arranged such that a straight line extending radially our from the centre of the aerosol-generating article may intersect both a capsule air outlet and at least one ventilation perforation.

The plurality of capsule air outlets may further comprise a capsule air outlet located a the centre of the circle.

This arrangement may mean that the ambient air provided by the at least one ventilation perforation is provided directly into the path of the vapour leaving the capsule through the capsule air outlets. This may advantageously improve the aerosol generation.

The aerosol-generating article may comprise the same number of ventilation perforations and capsule air outlets such that each capsule air outlet may have a corresponding ventilation perforation, each capsule air outlet being radially aligned with a corresponding ventilation perforation.

The arrangement of the plurality of capsule air outlets may be arranged on the circle such that each of the capsule air outlets radially overlaps with at least a portion of a ventilation perforation, and that each capsule air outlet radially overlaps with the same sized portion of ventilation perforation. This may advantageously improve the consistency of the aerosol generation since the vapour passing through each capsule air outlet should encounter a similar amount of ambient cooling air.

The angular diameter of each of the capsule air outlets (0c) measured from the centre of the circle may be greater than the angular distance between adjacent ventilation perforations (0s). In other words: This may advantageously ensure that every capsule air outlet radially overlaps with a portion of a ventilation perforation regardless of the orientation in which the capsule is provided in the hollow tubular element. This is advantageous since it may make manufacturing more straightforward since the desired radial overlap is achievable without needed to carefully control the orientation of the capsule during manufacturing.

The angular diameter of each of the capsule air outlets (0c) measured from the centre of the circle may be greater than the angular diameter of each ventilation perforation (0v) added to the angular distance between adjacent ventilation perforations (0s). In other words:

This may advantageously ensure that total radial overlap between each capsule air outlet and the ventilation perforations remails constant regardless of the orientation in which the capsule is provided in the hollow tubular element. This is advantageous since it may make manufacturing more straightforward since the desired radial overlap is achievable without needed to carefully control the orientation of the capsule during manufacturing.

The aerosol-generating articles of the present invention comprise an aerosol-generating substrate. The aerosol-generating substrate may be a solid aerosol-generating substrate contained within the capsule. The solid aerosol-generating substrate may comprise nicotine and an aerosol former but may take a variety of different forms.

The aerosol-generating substrate may comprise at least 15 percent by weight of aerosol former on a dry weight basis. Preferably, the aerosol-generating substrate comprises at least 20 percent by weight of aerosol former, on a dry weight basis. More preferably, the aerosolgenerating substrate comprises at least 25 percent by weight of aerosol former, on a dry weight basis. More preferably, the aerosol-generating substrate comprises at least 30 percent by weight of aerosol former, on a dry weight basis. More preferably, the aerosol-generating substrate comprises at least 35 percent by weight of aerosol former, on a dry weight basis. More preferably, the aerosol-generating substrate comprises at least 40 percent by weight of aerosol former, on a dry weight basis. More preferably, the aerosol-generating substrate comprises at least 45 percent by weight of aerosol former, on a dry weight basis. More preferably, the aerosol-generating substrate comprises at least 50 percent by weight of aerosol former, on a dry weight basis.

Preferably, the aerosol-generating substrate comprises no more than 80 percent by weight on a dry weight basis. More preferably, the second aerosol-generating substrate comprises no more than 75 percent by weight on a dry weight basis. More preferably, the second aerosol-generating substrate comprises no more than 70 percent by weight on a dry weight basis. For example, the aerosol-generating substrate may gave an aerosol former content of between 15 percent by weight and 80 percent by weight, or between 20 percent by weight and 80 percent by weight, or between 25 percent by weight and 80 percent by weight, or between 30 percent by weight and 75 percent by weight, or between 35 percent by weight and 75 percent by weight, or between 40 percent by weight and 70 percent by weight, or between 45 percent by weight and 70 percent by weight, or between 50 percent by weight and 70 percent by weight, on a dry weight basis.

In certain preferred embodiments, the aerosol former content of the aerosol-generating substrate may be between 40 percent and 80 percent by weight, or between 45 percent and 75 percent by weight, or between 50 percent and 70 percent by weight, on a dry weight basis. In such embodiments, the aerosol former content of the aerosol-generating substrate is therefore relatively high.

Suitable aerosol formers for inclusion in the aerosol-generating substrate are known in the art and include, but are not limited to: polyhydric alcohols, such as triethylene glycol, propylene glycol, 1 ,3-butanediol and glycerol; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate.

Preferably, the aerosol-generating substrate comprises glycerol as aerosol former.

The aerosol-generating substrate further comprises nicotine. As used herein with reference to the invention, the term “nicotine” is used to describe nicotine, a nicotine base or a nicotine salt. In embodiments in which the aerosol-generating substrate comprises a nicotine base or a nicotine salt, the amounts of nicotine recited herein are the amount of free base nicotine or amount of protonated nicotine, respectively.

The aerosol-generating substrate may comprise natural nicotine or synthetic nicotine. The nicotine may comprise one or more nicotine salts. The one or more nicotine salts may be selected from the list consisting of nicotine lactate, nicotine citrate, nicotine pyruvate, nicotine bitartrate, nicotine benzoate, nicotine pectate, nicotine alginate, and nicotine salicylate.

The nicotine may comprise an extract of tobacco.

Preferably, the aerosol-generating substrate comprises at least 0.5 percent by weight of nicotine on a dry weight basis. More preferably, the aerosol-generating substrate comprises at least 1 percent by weight of nicotine on a dry weight basis. Even more preferably, the aerosol-generating substrate comprises at least 2 percent by weight of nicotine on a dry weight basis. In addition, or as an alternative, the aerosol-generating substrate preferably comprises less than 10 percent by weight of nicotine on a dry weight basis. More preferably, the aerosolgenerating substrate comprises less than 8 percent by weight of nicotine on a dry weight basis. More preferably, the aerosol-generating substrate comprises less than 6 percent by weight of nicotine on a dry weight basis.

For example, the aerosol-generating substrate may comprise between 0.5 percent and 10 percent by weight of nicotine, or between 1 percent and 8 percent by weight of nicotine, or between 2 percent and 6 percent by weight of nicotine, on a dry weight basis.

The aerosol-generating substrate may comprise one or more carboxylic acids. Advantageously, including one or more carboxylic acids in the aerosol-generating substrate may create a nicotine salt.

The one or more carboxylic acids comprise one or more of lactic acid and levulinic acid. Advantageously, the present inventors have found that lactic acid and levulinic acid are particularly good carboxylic acids for creating nicotine salts.

Preferably, the aerosol-generating substrate comprises at least 0.5 percent by weight of carboxylic acid, on a dry weight basis. More preferably, the aerosol-generating substrate comprises at least 1 percent by weight of carboxylic acid, on a dry weight basis. More preferably, the aerosol-generating substrate comprises at least 2 percent by weight of carboxylic acid, on a dry weight basis.

In addition, or as an alternative, the aerosol-generating substrate preferably comprises less than 15 percent by weight of carboxylic acid, on a dry weight basis. More preferably, the aerosol-generating substrate preferably comprises less than 10 percent by weight of carboxylic acid, on a dry weight basis. More preferably, the aerosol-generating substrate preferably comprises less than 5 percent by weight of carboxylic acid, on a dry weight basis. For example, the aerosol-generating substrate may comprise between 0.5 percent and 15 percent by weight of carboxylic acid, or between 1 percent and 10 percent by weight of carboxylic acid, or between 2 percent and 5 percent by weight of carboxylic acid.

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

As used herein, the term “film” is used to describe a solid laminar element having a thickness that is less than the width or length thereof. The film may be self-supporting. In other words, a film may have cohesion and mechanical properties such that the film, even if obtained by casting a film-forming formulation on a support surface, can be separated from the support surface. Alternatively, the film may be disposed on a support or sandwiched between other materials. This may enhance the mechanical stability of the film. The solid aerosol-generating substrate may be provided in any suitable form. Preferably, the capsule contains a plurality of particles of the solid aerosol-generating substrate. For example, the capsule may comprise a plurality of beads, pellets, granules, strips, shreds or flakes of the aerosol-generating substrate.

In certain embodiments, the maximum dimension of each of the particles is preferably at least 0.05 millimetres, more preferably at least 0.1 millimetres, more preferably at least 0.15 millimetres, more preferably at least 0.2 millimetres, more preferably at least 0.25 millimetres, more preferably at least 0.5 millimetres, more preferably at least 0.75 millimetres, more preferably at least 1 millimetre. Preferably, the maximum dimension of each of the particles is no more than 10 millimetres, more preferably no more than 9 millimetres, more preferably no more than 8 millimetres, more preferably no more than 6 millimetres, more preferably no more than 5 millimetres. Providing relatively large particles within these ranges may be preferable when the capsule wall is provided with holes to form air inlets and outlets, as described below. The relatively large maximum dimension of the particles will then ensure that the particles are not lost through the holes in the capsule wall.

The maximum dimension of a particle corresponds to the largest external diameter of that particles. Where the particles are substantially spherical, the maximum dimension of a particle will correspond to the diameter of that particle.

In such embodiments, the capsule preferably comprises at least 2 particles of the aerosol-generating substrate, more preferably at least 5 particles of the aerosol-generating substrate, more preferably at least 10 particles of the aerosol-generating substrate, more preferably at least 20 particles of the aerosol-generating substrate, more preferably at least 30 particles. The capsule may contain up to 200 particles.

In other embodiments, the solid aerosol-generating substrate may be in the form of a powder having a larger number of much smaller particles. For example, in such embodiments, the powder may be formed of particles having a D50 size of between 50 micrometres and 80 micrometres, between 50 micrometres and 75 micrometres, between 55 micrometres and 75 micrometres, between 55 micrometres and 70 micrometres, or between 60 micrometres and 70 micrometres.

As used herein with reference to the present invention, the term “D50 size” refers to the median particle size of the particulate material or powder. The D50 size is the particle size which splits the distribution in half, where half of the particles are larger than the D50 size and half of the particles are smaller than the D50 size. The particle size distribution may be determined by laser diffraction. For example, the particle size distribution may be determined by laser diffraction using a Malvern Mastersizer 3000 laser diffraction particle size analyser in accordance with the manufacturer’s instructions. The powder may be formed of particles having a D95 size of between 80 micrometres and 130 micrometres, between 90 micrometres and 125 micrometres, between 100 micrometres and 120 micrometres, or between 110 micrometres and 120 micrometres.

As used herein with reference to the present invention, the term “D95 size” is the size at which the proportion by mass of particles with sizes below this value is 95 percent.

The powder may be formed of particles having a maximum diameter of between 50 micrometres and 250 micrometres, between 80 micrometres and 225 micrometres, or between 100 micrometres and 125 micrometres.

In embodiments where the capsule contains a plurality of particles, the mass of each particle is preferably at least 0.05 micrograms, more preferably at least 0.1 micrograms, more preferably at least 0.2 micrograms, more preferably at least 0.3 micrograms, more preferably at least 0.4 micrograms, more preferably at least 0.5 micrograms, more preferably at least 0.6 micrograms, more preferably at least 0.7 micrograms, more preferably at least 0.8 micrograms, more preferably at least 0.9 micrograms, more preferably at least 1 microgram, more preferably at least 10 micrograms, more preferably at least 100 micrograms, more preferably at least 200 micrograms, more preferably at least 500 micrograms, more preferably at least 1 milligram. The mass of each particle is preferably no more than 600 milligrams, more preferably no more than 500 milligrams, more preferably no more than 400 milligrams, more preferably no more than 300 milligrams, more preferably no more than 200 milligrams, more preferably no more than 100 milligrams, more preferably no more than 50 milligrams, more preferably no more than 10 milligrams.

Alternatively, the solid aerosol-generating substrate may be in the form of one or more sheets. As used herein with reference to the invention, the term “sheet” describes a laminar element having a width and length substantially greater than the thickness thereof.

The one or more sheets as described herein may have been one or more of crimped, folded, gathered and pleated. The one or more sheets may be cut into strands.

Aerosol-generating articles according to the invention may further comprise a downstream filter segment mounted within the hollow tubular element at a downstream end of the hollow tubular element. The downstream filter segment may extend to the downstream end of the hollow tubular element. The downstream end of the downstream filter segment may define the downstream end of the aerosol-generating article. The inclusion of a downstream filter segment within the hollow tubular element may be useful in order to provide a desired level of RTD for the aerosol-generating article.

The downstream filter segment is located downstream of the capsule and preferably, the capsule and the downstream filter segment are spaced apart in a longitudinal direction such that a cavity is defined between them. Preferably, the downstream filter segment is located at least 5 millimetres downstream from the downstream end of the capsule, more preferably at least 8 millimetres downstream from the downstream end of the capsule, more preferably at least 10 millimetres downstream from the downstream end of the capsule, more preferably at least 15 millimetres downstream from the downstream end of the capsule. Preferably, the downstream filter segment is located less than 30 millimetres downstream from the downstream end of the capsule, more preferably less than 25 millimetres downstream from the downstream end of the capsule. The distance defined between the downstream end of the capsule and the downstream filter segment corresponds to the length of the cavity between the capsule and the downstream filter segment.

The downstream filter segment is preferably a solid plug, which may also be described as a ‘plain’ plug and is non-tubular. The filter segment therefore preferably has a substantially uniform transverse cross section.

The downstream filter segment is preferably formed of a fibrous filtration material. The fibrous filtration material may be for filtering the aerosol that is generated from the aerosolgenerating substrate. Suitable fibrous filtration materials would be known to the skilled person. Particularly preferably, the at least one downstream filter segment comprises a cellulose acetate filter segment formed of cellulose acetate tow.

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

Preferably, the downstream filter segment has a low particulate filtration efficiency.

The downstream filter segment preferably has an external diameter that is approximately equal to the internal diameter of the hollow tubular element, so that the downstream filter segment is retained within the hollow tubular element by means of a friction fit.

Preferably, the external diameter of the downstream filter segment is between 5 millimetres and 12 millimetres, more preferably between 6 millimetres and 10 millimetres, more preferably between 7 millimetres and 8 millimetres.

Unless otherwise specified, the resistance to draw (RTD) of a component or the aerosolgenerating article is measured in accordance with ISO 6565-2015. The RTD refers the pressure required to force air through the full length of a component. The terms “pressure drop” or “draw resistance” of a component or article may also refer to the “resistance to draw”. Such terms generally refer to the measurements in accordance with ISO 6565-2015 are normally carried out at under test at a volumetric flow rate of 17.5 millilitres per second at the output or downstream end of the measured component at a temperature of 22 degrees Celsius, a pressure of 101 kPa (about 760 Torr) and a relative humidity of 60%. Conditions for smoking and smoking machine specifications are set out in ISO Standard 3308 (ISO 3308:2000). Atmosphere for conditioning and testing are set out in ISO Standard 3402 (ISO 3402:1999).

The resistance to draw (RTD) of the downstream filter segment may be at least 0 millimetres H2O, or at least 3 millimetres H2O, or at least 6 millimetres H2O.

The RTD of the downstream filter segment may be no greater than 12 millimetres H2O, or no greater than 11 millimetres H2O, or no greater than 10 millimetres H2O.

As mentioned above, the downstream filter segment may be formed of a fibrous filtration material. The downstream filter segment may be formed of a porous material. The downstream filter segment may be formed of a biodegradable material. The downstream filter segment may be formed of a cellulose material, such as cellulose acetate. For example, a downstream filter segment may be formed from a bundle of cellulose acetate fibres having a denier per filament between 10 and 15. For example, a downstream filter segment formed from relatively low density cellulose acetate tow, such as cellulose acetate tow comprising fibres of 12 denier per filament.

The downstream filter segment may be formed of a polylactic acid based material. The downstream filter segment may be formed of a bioplastic material, preferably a starch-based bioplastic material. The downstream filter segment may be made by injection moulding or by extrusion. Bioplastic-based materials are advantageous because they are able to provide downstream filter segment structures which are simple and cheap to manufacture with a particular and complex cross-sectional profile, which may comprise a plurality of relatively large air flow channels extending through the downstream filter segment material, that provides suitable RTD characteristics.

The length of the downstream filter segment may be at least 5 millimetres, or at least 8 millimetres, or at least 10 millimetres. The length of the downstream filter segment may be less than 20 millimetres, or less than 15 millimetres, or less than 12 millimetres. For example, the length of the downstream filter segment may be between 5 millimetres and 20 millimetres, or between 8 millimetres and 15 millimetres, or between 8 millimetres and 12 millimetres, or between 10 millimetres and 12 millimetres.

In alternative embodiments of the present invention, a downstream filter segment may be provided downstream of the hollow tubular element. The downstream filter segment may extend between the hollow tubular element and the downstream end of the aerosol-generating article. In such embodiments, the downstream filter segment may be connected to the hollow tubular element by means of a tipping wrapper.

The overall RTD of the aerosol-generating article may be at least 1 millimetre H2O. For example, the overall RTD of the aerosol-generating article may be at least 2 millimetres H2O, at least 3 millimetres H2O, at least 4 millimetres H2O, at least 5 millimetres H2O, at least 6 millimetres H2O, at least 7 millimetres H2O, at least 8 millimetres H2O, at least 9 millimetres H2O, at least 10 millimetres H2O, at least 15 millimetres H2O, at least 20 millimetres H2O, at least 30 millimetres H2O, at least 40 millimetres H2O, or at least 50 millimetres H2O.

The overall RTD of the aerosol-generating article may be no more than 180 millimetres H2O. For example, the overall RTD of the aerosol-generating article may be no more than 170 millimetres H2O, no more than 160 millimetres H2O, no more than 150 millimetres H2O, or no more than 140 millimetres H2O.

The overall RTD of the aerosol-generating article may be between 1 millimetre H2O and 180 millimetres H2O. For example, the overall RTD of the aerosol-generating article may be between 5 millimetres H2O and 170 millimetres H2O, between 10 millimetres H2O and 160 millimetres H2O, between 20 millimetres H2O and 150 millimetres H2O, or between 50 millimetres H2O and 140 millimetres H2O.

The aerosol-generating article in accordance with the invention may have an overall length of at least 40 millimetres, or at least 50 millimetres, or at least 60 millimetres.

An overall length of an aerosol-generating article in accordance with the invention may be less than or equal to 90 millimetres, or less than or equal to 85 millimetres, or less than or equal to 80 millimetres.

In some embodiments, an overall length of the aerosol-generating article is preferably from 40 millimetres to 70 millimetres, more preferably from 45 millimetres to 70 millimetres. In other embodiments, an overall length of the aerosol-generating article is preferably from 40 millimetres to 60 millimetres, more preferably from about 45 millimetres to about 60 millimetres. In further embodiments, an overall length of the aerosol-generating article is preferably from 40 millimetres to 50 millimetres, more preferably from 45 millimetres to 50 millimetres. In an exemplary embodiment, an overall length of the aerosol-generating article is about 45 millimetres.

The aerosol-generating article may have an external diameter of at least 5 millimetres, or at least 6 millimetres, or at least 7 millimetres.

The aerosol-generating article may have an external diameter of less than or equal to about 12 millimetres, or less than or equal to about 10 millimetres, or less than or equal to about 8 millimetres.

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

The external diameter of the aerosol-generating article may be substantially constant over the whole length of the article. As an alternative, different portions of the aerosolgenerating article may have different external diameters.

According to a second aspect of the present invention, there is further provided an aerosol-generating system comprising the aerosol-generating article of the first aspect of the present invention; and an aerosol-generating device comprising a heating chamber for receiving the aerosol-generating article, and a heating element provided in the heating chamber or about the periphery of the heating chamber.

The aerosol-generating device may comprise an upstream end and a downstream end. The aerosol-generating device may comprise a body. The body or housing of the aerosolgenerating device may define a heating chamber for removably receiving the aerosolgenerating article at the downstream end of the device. The aerosol-generating device comprises a heating element or heater for heating the aerosol-generating substrate when the aerosol-generating article is received within the heating chamber.

The heating chamber may extend between an upstream end and a downstream end. The upstream end of the heating chamber may be a closed end and the downstream end of the heating chamber may be an open end. An aerosol-generating article may be inserted into the heating chamber, via the open end of the heating chamber. The heating chamber may be cylindrical in shape so as to conform to the same shape of an aerosol-generating article.

The expression “received within” may refer to the fact that a component or element is fully or partially received within another component or element. For example, the expression “aerosol-generating article is received within the heating chamber” refers to the aerosolgenerating article being fully or partially received within the heating chamber of the aerosolgenerating article. When the aerosol-generating article is received within the heating chamber, the aerosol-generating article may abut the upstream end of the heating chamber. When the aerosol-generating article is received within the heating chamber, the aerosolgenerating article may be in substantial proximity to the upstream end of the heating chamber. The upstream end of the heating chamber may be defined by an end-wall.

The length of the heating chamber may be between 15 millimetres and 80 millimetres, or between 20 millimetres and 70 millimetres, or between 25 millimetres and 60 millimetres, or between 25 millimetres and 50 millimetres. The length of the heating chamber may be between 25 millimetres and 29 millimetres, or between 26 millimetres and 29 millimetres, or between 27 millimetres or 28 millimetres.

When the aerosol-generating article is received within the heating chamber, the capsule is preferably fully within the device cavity, in order to optimise the heating of the solid aerosolgenerating substrate within the capsule. The length of the device cavity is therefore preferably greater than the length of the capsule.

A diameter of the heating chamber may be between 4 millimetres and 10 millimetres. A diameter of the heating chamber may be between 5 millimetres and 9 millimetres. A diameter of the heating chamber may be between 6 millimetres and 8 millimetres. A diameter of the heating chamber may be between 6 millimetres and 7 millimetres.

A diameter of the heating chamber may be substantially the same as or greater than a diameter of the aerosol-generating article. A diameter of the heating chamber may be the same as a diameter of the aerosol-generating article in order to establish a tight fit with the aerosol-generating article.

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

Such a tight fit may establish an airtight fit or configuration between the heating chamber and an aerosol-generating article received therein.

With such an airtight configuration, there would be substantially no gap or empty space between the peripheral wall defining the heating chamber and the aerosol-generating article for air to flow through.

The tight fit with an aerosol-generating article may be established along the entire length of the heating chamber or along a portion of the length of the heating chamber.

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

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

The air-flow channel of the aerosol-generating device may extend from an inlet located at the downstream end of the aerosol-generating device to an outlet located away from the downstream end of the device. The air-flow channel may extend along a direction parallel to the longitudinal axis of the aerosol-generating device.

The heater may be any suitable type of heater. Preferably, in the present invention, the heater is an external heater which heats the capsule and its contents externally. Such an external heater may circumscribe the aerosol-generating article when inserted in or received within the aerosol-generating device.

Alternatively, the heater may be an elongate heater blade that is adapted to be inserted into the capsule in order to internally heat the capsule and its contents.

The heater may comprise at least one heating element. The at least one heating element may be any suitable type of heating element. In some embodiments, the device comprises only one heating element. In some embodiments, the device comprises a plurality of heating elements.

The heating element may be a resistive heating element.

Suitable materials for forming the resistive heating element include but are not limited to: semiconductors such as doped ceramics, electrically ‘conductive’ ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys and composite materials made of a ceramic material and a metallic material. Such composite materials may comprise doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbides. Examples of suitable metals include titanium, zirconium, tantalum and metals from the platinum group. Examples of suitable metal alloys include stainless steel, nickel-, cobalt-, chromium-, aluminium- titanium- zirconium-, hafnium-, niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese- and iron-containing alloys, and super-alloys based on nickel, iron, cobalt, stainless steel, Timetai® and iron-manganese-aluminium based alloys. In some embodiments, the resistive heating element comprises one or more stamped portions of electrically resistive material, such as stainless steel. Alternatively, the at least one resistive heating element may comprise a heating wire or filament, for example a Ni-Cr (Nickel- Chromium), platinum, tungsten or alloy wire.

In some embodiments, the heating element comprises an electrically insulating substrate, wherein the at least one resistive heating element is provided on the electrically insulating substrate.

The electrically insulating substrate may comprise any suitable material. For example, the electrically insulating substrate may comprise one or more of: paper, glass, ceramic, anodized metal, coated metal, and Polyimide. The ceramic may comprise mica, Alumina (AI2O3) or Zirconia (ZrCh). Preferably, the electrically insulating substrate has a thermal conductivity of less than or equal to about 40 Watts per metre Kelvin, preferably less than or equal to about 20 Watts per metre Kelvin and ideally less than or equal to about 2 Watts per metre Kelvin.

The heater may comprise a heating element comprising a rigid electrically insulating substrate with one or more electrically conductive tracks or wire disposed on its surface. The size and shape of the electrically insulating substrate may allow it to be inserted directly into an aerosol-generating substrate. If the electrically insulating substrate is not sufficiently rigid, the heating element may comprise a further reinforcement means. A current may be passed through the one or more electrically conductive tracks to heat the heating element and the aerosol-generating substrate.

In some embodiments, the heater comprises an inductive heating arrangement. The inductive heating arrangement may comprise an inductor coil and a power supply configured to provide high frequency oscillating current to the inductor coil. As used herein, a high frequency oscillating current means an oscillating current having a frequency of between about 500 kHz and about 30 MHz. The heater may advantageously comprise a DC/AC inverter for converting a DC current supplied by a DC power supply to the alternating current. The inductor coil may be arranged to generate a high frequency oscillating electromagnetic field on receiving a high frequency oscillating current from the power supply. The inductor coil may be arranged to generate a high frequency oscillating electromagnetic field in the device cavity. In some embodiments, the inductor coil may substantially circumscribe the device cavity. The inductor coil may extend at least partially along the length of the device cavity.

The heater may comprise an inductive heating element. The inductive heating element may be a susceptor element. A susceptor element may be arranged such that, when the aerosol-generating article is received in the cavity of the aerosol-generating device, the oscillating electromagnetic field generated by the inductor coil induces a current in the susceptor element, causing the susceptor element to heat up. In these embodiments, the aerosol-generating device is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of between 1 and 5 kilo amperes per metre (kA m), preferably between 2 and 3 kA/m, for example about 2.5 kA/m. The electrically- operated aerosol-generating device is preferably capable of generating a fluctuating electromagnetic field having a frequency of between 1 and 30 MHz, for example between 1 and 10 MHz, for example between 5 and 7 MHz.

In these embodiments, the susceptor element is preferably located in contact with the solid aerosol-generating substrate. In some embodiments, a susceptor element is located in the aerosol-generating device. In these embodiments, the susceptor element may be located in the cavity. The aerosol-generating device may comprise only one susceptor element. The aerosol-generating device may comprise a plurality of susceptor elements. In some embodiments, the susceptor element is preferably arranged to heat the outer surface of the aerosol-generating substrate.

The susceptor element may comprise any suitable susceptor element.

In some embodiments the aerosol-generating device may comprise at least one resistive heating element and at least one inductive heating element. In some embodiments the aerosol-generating device may comprise a combination of resistive heating elements and inductive heating elements.

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

The aerosol-generating device may comprise a power supply. The power supply may be a DC power supply. In some embodiments, the power supply is a battery. The power supply may be a nickel-metal hydride battery, a nickel cadmium battery, or a lithium based battery, for example a lithium-cobalt, a lithium-iron-phosphate or a lithium-polymer battery. However, in some embodiments the power supply may be another form of charge storage device, such as a capacitor. The power supply may require recharging and may have a capacity that allows for the storage of enough energy for one or more user operations, for example one or more aerosol-generating experiences.

The aerosol-generating device may comprise a piercing device for piercing the capsule when the aerosol-generating article is inserted into the device cavity. As described above, the piercing of the capsule may be necessary in order to establish one or more airflow pathways through the capsule. Below, there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

Example 1 : An aerosol-generating article for generating an inhalable aerosol upon heating, the article comprising: a hollow tubular element, and a capsule mounted within the hollow tubular element at an upstream end of the hollow tubular element, the capsule containing an aerosol-generating substrate, the hollow tubular element comprising a ventilation zone to allow external air to enter the aerosol-generating article, the ventilation zone being provided downstream of the downstream end of the capsule.

Example 2: An aerosol-generating article according to Example 1 , wherein the ventilation zone comprises at least one ventilation perforation.

Example 3: An aerosol-generating article according to Example 2, wherein the ventilation zone comprises a plurality of ventilation perforations through the hollow tubular element.

Example 4: An aerosol-generating article according to Example 3, wherein the ventilation zone comprises at least 5 ventilation perforations through the hollow tubular element.

Example 5: An aerosol-generating article according to Example 3 or Example 4, wherein the ventilation zone comprises no more than 15 ventilation perforations through the hollow tubular element.

Example 6: An aerosol-generating article according to any one of Examples 3 to 5, wherein the plurality of ventilation perforations comprises at least one perforation having a width of no more than 200 micrometres.

Example 7: An aerosol-generating article according to any one of Examples 3 to 6, wherein the plurality of ventilation perforations comprises at least one perforation having a width of at least 50 micrometres.

Example 8: An aerosol-generating article according any one of Examples 3 to 7, wherein the plurality of ventilation perforations comprises at least one perforation having a length of at least 400 micrometres.

Example 9: An aerosol-generating article according to any one of Examples 3 to 8, wherein the plurality of ventilation perforations comprises at least one perforation having a length of no more than 1 millimetres. Example 10: An aerosol-generating article according to any one of Examples 3 to 9, wherein the plurality of ventilation perforations form a line of perforations which circumscribes the hollow tubular element.

Example 11 : An aerosol-generating article according to any one of Examples 3 to 10, further comprising at least one stop protruding from the inner surface of the hollow tubular element to prevent the capsule from moving further downstream than the at least one stop.

Example 12: An aerosol-generating article according to Example 11 , wherein the at least one stop is located upstream of the ventilation zone.

Example 13: An aerosol-generating article according to Example 11 or Example 12, wherein the at least one stop comprises an embossed potion of the hollow tubular element extending into the interior of the hollow tubular element.

Example 14: An aerosol-generating article according to any one of Examples 11 to 13, wherein the hollow tubular element comprises at least one flap, the at least one flap formed from a portion of the hollow tubular element which is partially detached from the remainder of the hollow tubular element forming a gap between the flap and the remainder of the hollow tubular element, the flap remaining attached to the remainder of the hollow tubular element along an attachment line, wherein the flap extends into the interior or the hollow tubular element such that: the at least one stop comprises the at least flap, and the at least one ventilation perforation comprises the gap between the flap and the remainder of the hollow tubular element.

Example 15: An aerosol-generating article according to Example 14, wherein the attachment line is located at the upstream end of the flap.

Example 16: An aerosol-generating article according to any one of Example 3 to Example 15, wherein the capsule comprises at least one capsule air inlet located at the upstream end of the capsule, and at least one capsule air outlet located at the downstream end of the capsule.

Example 17: An aerosol-generating article according to Example 16, wherein the at least one capsule air outlet comprises a plurality of air outlets located at the downstream end of the capsule, the plurality of air outlets being arranged on the circumference of a circle centred on the longitudinal axis of the capsule, the circle having a diameter less than the diameter of the aerosol-generating article.

Example 18: An aerosol-generating article according to Example 17, wherein the plurality of capsule air outlets are arranged on the circle such that each of the capsule air outlets radially overlaps with at least a portion of a ventilation perforation. Example 19: An aerosol-generating article according to Example 18, wherein the angular diameter of each of the plurality of capsule air outlets measured from the centre of the circle is greater than the angular distance between adjacent ventilation perforations of the ventilation zone.

Example 20: An aerosol-generating article according to Example 19, wherein the angular diameter of each of the plurality of capsule air outlets measured from the centre of the circle is greater than the angular diameter of each ventilation perforation added to the angular distance between adjacent ventilation perforations of the ventilation zone.

Example 21 : An aerosol-generating article according to any preceding Example, wherein the ventilation zone comprises a porous portion of the hollow tubular element.

Example 22: An aerosol-generating article according to any preceding Example, wherein the external diameter of the capsule is approximately the same as the inner diameter of the hollow tubular element.

Example 23: An aerosol-generating article according to any preceding Example, wherein the upstream end of the ventilation zone is located at least 20 millimetres from the upstream end of the aerosol-generating article.

Example 24: An aerosol-generating article according to any preceding Example, wherein the upstream end of the ventilation zone is located no more than 37 millimetres from the upstream end of the aerosol-generating article.

Example 25: An aerosol-generating article according to any preceding Example, wherein the upstream end of ventilation zone is located no more than 8 millimetres from the downstream end of the capsule.

Example 26: An aerosol-generating article according to any preceding Example, wherein the ventilation level of the aerosol-generating article provided by the ventilation zone is at least 20 percent.

Example 27: An aerosol-generating system comprising: an aerosol-generating article according to any one of Examples 1 to 26; and an aerosol-generating device comprising a heating chamber for receiving the aerosolgenerating article and a heating element provided in the heating chamber or about the periphery of the heating chamber.

In the following, the invention will be further described with reference to the drawings of the accompanying Figures, wherein:

Figure 1 shows a schematic side sectional view of an aerosol-generating article in accordance with an embodiment of the invention;

Figure 2 shows a close-up, schematic side sectional view of a portion of an aerosolgenerating article in accordance with an embodiment of the invention; Figure 3 shows a schematic sectional view along the longitudinal axis of a first aerosolgenerating article in accordance with an embodiment of the invention;

Figure 4 shows a schematic sectional view along the longitudinal axis of a second aerosol-generating article in accordance with an embodiment of the invention;

Figure 5 shows a schematic sectional view along the longitudinal axis of a third aerosolgenerating article in accordance with an embodiment of the invention; and

Figure 6 shows a schematic side sectional view of an aerosol-generating system in accordance with an embodiment of the invention.

The aerosol-generating article 10 shown in Figure 1 comprises a hollow tubular element 101 and a capsule 102 mounted within the hollow tubular element 101.

The hollow tubular element 101 is formed from cardboard and has a cylindrical shape extending from an upstream end to a downstream end. The hollow tubular element 101 has a constant outer diameter of about 7.2 millimetres and a constant inner diameter of about 6.7 millimetres. The hollow tubular element 101 therefore has a wall thickness of about 0.25 millimetres. The hollow tubular element 101 has a length of about 40 millimetres.

The capsule 102 comprises an outer wall formed from air impermeable polymer such as HPMC. The capsule 102 has an elongate, capsule (sphero-cylindrical) shape with a round cross section. The capsule comprises a capsule outer wall defining an internal cavity which contains a plurality of beads of solid aerosol-generating substrate (not shown in Figure 1). The solid aerosol-generating substrate comprises nicotine and glycerin as an aerosol former. The capsule outer wall is defined by a cylindrical wall and opposed hemispherical end walls at the upstream and downstream end of the capsule 102. The capsule 102 has a length of about 20 millimetres and an external diameter of about 6.7 millimetres. The external diameter of the capsule 102 is therefore similar to the internal diameter of the hollow tubular element

101 such that the capsule 102 is retained within the hollow tubular element 101 by means of a friction fit.

The capsule 102 has an internal volume of about 600 cubic millimetres and contains about 200 milligrams of the solid aerosol-generating substrate. The capsule therefore contains approximately 0.33 milligrams of aerosol-generating substrate per cubic millimetre of the internal cavity.

The capsule 102 comprises a plurality of capsule air inlets 105 at the upstream end of the capsule 102, on the hemispherical upstream end wall of the capsule 102. The capsule

102 comprises a plurality of capsule air outlets 106 at the downstream end of the capsule 102, on the hemispherical downstream end wall of the capsule 102. The arrangement of the capsule air inlets 105 and capsule air outlets 106 is set out in more detail below. The hollow tubular element 101 comprises a ventilation zone to allow external air to enter the aerosol-generating article. The ventilation zone is provided downstream of the downstream end of the capsule 102. More specifically, the upstream end of the ventilation zone is aligned with the downstream end of the capsule 102.

The ventilation zone comprises 10 ventilation perforations 102 which extend through the hollow tubular element 101. The ventilation perforations 102 are evenly spaced from one- another, and are arranged in a line circumscribing the hollow tubular element 101. The ventilation perforations 102 are all the same size. Each ventilation perforation 102 has a width of 100 micrometres and a length of 600 micrometres. The ventilation zone provides a ventilation level of at least 20 percent.

The aerosol-generating article 10 further comprises at least one stop 107 protruding from the inner surface of the hollow tubular element 101 to prevent the capsule 102 from moving further downstream than the at least one stop 107. In the aerosol-generating article 10 shown in Figure 1 , the at least one stop 107 comprises an annular flange attached to and extending from the inner surface of the hollow tubular element 101. The inner diameter of the flange is smaller than the outer diameter of the capsule 102 thereby preventing the capsule from moving further downstream than the stop 107. The at least one stop 107 is located upstream of the ventilation zone.

The aerosol-generating article 10 further comprises an empty cavity 104 downstream of the capsule 102 and a downstream filter segment 108 downstream of the empty cavity 104. The empty cavity 104 extends from the downstream end of the capsule 102 to the upstream end of the downstream filter segment 108. The empty cavity 104 has a length of about 20 millimetres.

The downstream filter segment 108 extends from the downstream end of the empty cavity 104 to the downstream end of the aerosol-generating article. The downstream filter segment 108 is formed from cellulose acetate tow.

Figure 2 shows a portion of an alternative aerosol-generating article 10 according to the present invention. As shown in Figure 2, the hollow tubular element 101 comprises a plurality of flaps which are cut from the hollow tubular element 101 . The flaps are detached from the hollow tubular element 101 at a downstream end of the flaps but attached to the hollow tubular element 101 at an upstream end. As can be seen in Figure 2, these flaps may be formed during manufacture by an angled piercing element 201 which cuts the hollow tubular element 101 and folds the flap inwardly.

In this example, the holes in the hollow tubular element 101 formed by the piercing element 201 form the ventilation perforations 103 to allow ambient air to enter the aerosol- generating article 10, and the flaps of material form the at least one stop 107 to prevent the capsule 102 from moving any further downstream.

Figure 3 shows a sectional view of an aerosol-generating article 10 viewed along the longitudinal axis of the article at position ‘A’ marked in Figure 1. As shown in Figure 3, the capsule 102 includes four capsule air outlets 106 arranged on a circle 301 , with a further capsule air outlet arranged at the centre of the downstream end of the capsule 102. The aerosol-generating article 10 shown in Figure 3 further includes a ventilation zone comprising four ventilation perforations 103 through the hollow tubular element 101. Each capsule air outlet 106 is arranged to radially overlap with a ventilation perforation 103. This radial overlap is demonstrated by the radius line 302 which clearly intersects with both a capsule air outlet 106 and a ventilation perforation 103.

Figure 4 shows a sectional view of a further aerosol-generating article 10 viewed along the longitudinal axis of the article at position ‘A’ marked in Figure 1 . The aerosol-generating article 10 shown in Figure 4 includes a ventilation zone comprising eight ventilation perforations 103 through the hollow tubular element 101. The angular diameter of the capsule air outlets (0c) and the angular distance between adjacent ventilation perforations (0s) are shown. The angular diameter of the capsule air outlets (0c) is greater than the angular distance between adjacent ventilation perforations (0s).

Figure 5 shows a sectional view of a further aerosol-generating article 10 viewed along the longitudinal axis of the article at position ‘A’ marked in Figure 1 . The aerosol-generating article 10 shown in Figure 5 includes a ventilation zone comprising eighteen ventilation perforations 103 through the hollow tubular element 101. The angular diameter of the capsule air outlets (0c) is shown. The angular diameter of each ventilation perforation (0v) added to the angular distance between adjacent ventilation perforations (0s) is also shown. The angular diameter of the capsule air outlets (0c) is greater than the angular diameter of each ventilation perforation (0v) added to the angular distance between adjacent ventilation perforations (0s).

Figure 6 shows an aerosol-generating system 20 according to the present invention. The system 20 comprises an aerosol-generating article 10 as described above. The system 20 further comprises an aerosol-generating device 30. The aerosol-generating device 30 comprises a device housing 601. The housing 601 defines a heating chamber 602 for receiving the upstream end of the aerosol-generating article 20. The heating chamber 602 has an inner diameter which substantially corresponds to the outer diameter of the aerosolgenerating article 10. The heating chamber 602 has a length of about 30 millimetres.

The aerosol-generating device 30 further comprises a heating element or heater 603 for heating the aerosol-generating substrate when the aerosol-generating article 10 is received within the heating chamber 602. The heater 603 is an external heater which circumscribes the heating chamber 602. The heater 603 is a resistive heater and is connected to a power supply (not shown), and is controlled using control circuitry (not shown).

The aerosol-generating device 30 further comprises a plurality of device air inlets 604 to allow air to enter the heating chamber 602 of the device 30.

In use, the upstream end of the aerosol-generating article 10 is inserted into the heating chamber 602 of the aerosol-generating device 30. The heater 603 is activated and the aerosol-generating substrate is heated within the capsule 102. The heated aerosol-generating substrate generates a vapour. When a pressure drop is applied to the downstream end of the aerosol-generating article, ambient air is drawn through the device air inlets 604 and through the capsule air inlets 105 and into the capsule 102. Here the air becomes entrained with the vapour before it leaves the capsule 102 through the capsule air outlets 106. Here the air mixes with ambient air drawn through the ventilation perforations 103 which cools the vapour promoting the nucleation and condensation of an aerosol. The aerosol then passes through the downstream filter segment 108 and out of the downstream end of the aerosol-generating article.

For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ± 10% of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.