CN117794404A

CN117794404A - Aerosol-generating article with inclined perforations in ventilation zone

Info

Publication number: CN117794404A
Application number: CN202280054624.4A
Authority: CN
Inventors: A·博尼奇; A·拉乌; M·奈索维奇; P·奥索里尼
Original assignee: Philip Morris Products SA
Current assignee: Philip Morris Products SA
Priority date: 2021-08-31
Filing date: 2022-08-29
Publication date: 2024-03-29
Also published as: WO2023031089A1; KR20240046729A

Abstract

The present invention relates to an aerosol-generating article comprising a rod of aerosol-generating substrate. The aerosol-generating article further comprises a ventilation zone arranged downstream of the strip of aerosol-generating substrate. The ventilation zone includes perforations (62). Perforations are arranged in the peripheral wall of the ventilation zone. Each perforation has a central axis (CA _PER ). The aerosol-generating article has a central axis (CAART). The minimum distance (d) between the central axis of each perforation and the central axis of the aerosol-generating article is between 3% and 15% of the outer diameter of the aerosol-generating article. The peripheral wall of the ventilation zone has a thickness of between 0.1 mm and 2.5 mm. The aerosol-generating article has a ventilation level of at least 20%. The invention further relates toAnd an aerosol-generating system comprising an aerosol-generating device having a cavity for receiving an aerosol-generating article. The invention further relates to a method for manufacturing an aerosol-generating article.

Description

Aerosol-generating article with inclined perforations in ventilation zone

Technical Field

The present invention relates to an aerosol-generating article. The aerosol-generating article may comprise an aerosol-generating substrate and may be adapted to produce an inhalable aerosol upon heating. The invention further relates to an aerosol-generating system comprising an aerosol-generating device having a cavity for receiving an aerosol-generating article. The invention further relates to a method for manufacturing an aerosol-generating article.

Background

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

A number of prior art documents disclose aerosol-generating devices for consuming aerosol-generating articles. Such devices include, for example, electrically heated aerosol-generating devices in which an aerosol is generated by transferring heat from one or more electric heater elements of the aerosol-generating device to an aerosol-generating substrate of a heated aerosol-generating article. For example, electrically heated aerosol-generating devices have been proposed which comprise an internal heating plate adapted to be inserted into an aerosol-generating substrate. As an alternative, an inductively heatable aerosol-generating article is proposed, comprising an aerosol-generating substrate and a susceptor arranged within the aerosol-generating substrate. Alternatively, the susceptor means may be arranged in the aerosol-generating device, such as at least partially surrounding a cavity for receiving the aerosol-generating article.

Aerosol-generating articles in which a tobacco-containing substrate is heated without combustion present many challenges not encountered by conventional smoking articles. First, the tobacco-containing substrate is typically heated to a significantly lower temperature than the temperature reached by the combustion front in a conventional cigarette. This may affect the nicotine release of the tobacco-containing substrate and the delivery of nicotine to the consumer. At the same time, if the heating temperature is increased in an attempt to enhance nicotine delivery, the generated aerosol typically needs to be cooled to a greater extent and faster before it reaches the consumer. However, technical solutions commonly used to cool mainstream smoke in conventional smoking articles (such as providing a high filtration efficiency segment at the mouth end of a cigarette) may have undesirable effects in aerosol-generating articles in which the tobacco-containing substrate is heated without combustion, as they may reduce delivery of nicotine. Second, there is a widely recognized need for aerosol-generating articles that are easy to use and have improved utility.

Disclosure of Invention

It is desirable to provide an aerosol-generating article that can be manufactured efficiently and at high speeds, preferably with satisfactory RTD and low RTD variability from article to article. It is desirable to provide an aerosol-generating article that provides efficient cooling. It is desirable to provide an aerosol-generating article that provides efficient cooling of the aerosol. It is desirable to provide an aerosol-generating article that provides efficient cooling of a vaporised aerosol-forming substrate. It is desirable to provide an aerosol-generating article that provides efficient mixing of ambient air with a vaporized aerosol-forming substrate.

It is desirable to provide new and improved aerosol-generating articles suitable for achieving at least one of the above-mentioned desired results.

According to an embodiment of the invention, an aerosol-generating article is provided, which may comprise a strip of aerosol-generating substrate. The aerosol-generating article may further comprise a ventilation zone arranged downstream of the strip of aerosol-generating substrate. The ventilation zone may include perforations. Perforations may be arranged in the peripheral wall of the ventilation zone. Each perforation may have a central axis. The aerosol-generating article may have a central axis. The minimum distance between the central axis of each perforation and the central axis of the aerosol-generating article may be between 3% and 15% of the outer diameter of the aerosol-generating article. The thickness of the peripheral wall of the ventilation zone may be between 0.1 mm and 2.5 mm.

According to an embodiment of the invention, an aerosol-generating article comprising a rod of aerosol-generating substrate is provided. The aerosol-generating article further comprises a ventilation zone arranged downstream of the strip of aerosol-generating substrate. The ventilation zone includes perforations. Perforations are arranged in the peripheral wall of the ventilation zone. Each perforation has a central axis. The aerosol-generating article has a central axis. The minimum distance between the central axis of each perforation and the central axis of the aerosol-generating article is between 3% and 15% of the outer diameter of the aerosol-generating article. The peripheral wall of the ventilation zone has a thickness of between 0.1 mm and 2.5 mm.

In other words, the direction of extension of the perforations may be inclined with respect to the radial direction of extension of the aerosol-generating article.

Having a ventilation zone with perforations may enable ambient air to be drawn into the ventilation zone. This ambient air may be mixed with air drawn through the strip of aerosol-forming substrate. The strip of aerosol-forming substrate may be heated by the aerosol-generating device such that the aerosol-forming substrate volatilizes. The volatilized aerosol-forming substrate may be entrained in air flowing through the strip of aerosol-forming substrate. This air stream is mixed with ambient air downstream of the strip of aerosol-forming substrate in the ventilation zone. The mixture of ambient air and air drawn through the strip of aerosol-forming substrate cools to form an aerosol.

Such tilting of the perforations may result in turbulence of the ambient air sucked into the ventilation zone via the perforations. This may improve the mixing of ambient air with air drawn through the strip of aerosol-forming substrate. This in turn may lead to improved aerosol generation.

The central axis of the individual perforations may be defined by an axis extending through the peripheral cross-sectional center of the perforation and the inner cross-sectional center of the perforation. The perimeter cross-sectional center of the perforation may be the cross-sectional center of the perforation at the outermost open area of the perforation. The inner cross-sectional center of the perforation may be the cross-sectional center of the perforation at the innermost open area of the perforation.

The perforations have an extension or length as described herein. The extension results from the relatively large thickness of the peripheral wall of the ventilation zone, as the perforations perforate the peripheral wall of the ventilation zone. Due to the extension of the perforations, the cross-sectional shape of the perforations may vary over the extension of the perforations. Furthermore, the perforations may be inclined due to the extension of the perforations. The extension of the perforation has the same magnitude as the diameter of the perforation. The direction of extension may thus influence the air flow through the perforations, in particular change the direction of the air flow through the perforations. As described herein, turbulent airflow may be created by tilting the direction of extension of the perforations relative to the cross-sectional center of the ventilation zone.

The minimum distance between the central axis of each perforation and the central axis of the aerosol-generating article may be between 3% and 15% of the outer diameter of the aerosol-generating article, preferably between 4% and 13% of the outer diameter of the aerosol-generating article, more preferably between 5% and 10% of the outer diameter of the aerosol-generating article, most preferably 6% of the outer diameter of the aerosol-generating article.

Having a larger distance between the central axis of each perforation and the central axis of the aerosol-generating article may increase turbulence in the ambient air drawn through the perforations and may thus increase mixing of the ambient air with the air drawn through the strips of aerosol-forming substrate.

Each central axis of each perforation may be at an angle of between 3 ° and 20 °, preferably between 4 ° and 15 °, more preferably between 5 ° and 10 °, most preferably at an angle of 7 °, with respect to the radial direction of the aerosol-generating article.

Such tilting of the orientation of the perforations relative to the cross-sectional center of the ventilation zone may result in turbulent airflow of ambient air being drawn through the perforations. This turbulent airflow may increase the mixing of ambient air with air drawn through the strips of aerosol-forming substrate.

Each perforation may have a length or extension measured along the central axis of the perforation. The one or more perforations may have a length of at least between 0.1 mm and 2.7 mm, preferably between 0.8 mm and 2.4 mm, more preferably between 1.2 mm and 2.0 mm, and most preferably about 1.7 mm. Due to the oblique extension of the perforations, the length of the perforations is preferably slightly greater than the thickness of the peripheral wall of the ventilation zone.

The length of the perforations may cause the perforations to affect the airflow through the perforations. The air flow may be directed by the shape of the perforations. The inclination of the perforations as described herein may result in turbulent airflow as the air exits the perforations.

In one embodiment, all perforations are inclined in the same direction. All perforations may be inclined at the same angle with respect to the radial direction. This may create a spiral turbulent airflow to enhance mixing of ambient air with air drawn through the strip of aerosol-forming substrate.

The cross-sectional shape of the one or more perforations may be constant along the central axis of the perforation. The one or more perforations may have a cylindrical shape. The one or more perforations may have a hollow cylindrical shape. The one or more perforations may have a hollow tubular shape.

One or more of the perforations may have a non-circular cross-section. One or more of the perforations may be slit-shaped or may have an oval cross-section. Preferably, one or more of the perforations may have an ovality of at least 1.5, preferably at least 2, preferably at least 3, more preferably at least 4, most preferably at least 5, the ovality being the ratio of the major diameter of the perforation divided by the minor diameter of the perforation.

One or more of the perforations may be slit-shaped or may have an oval cross-section.

Having a non-circular cross-section may improve the mixing of ambient air drawn into the ventilation zone via the perforations with air drawn into the ventilation zone via the strip of aerosol-forming substrate. The flow of ambient air drawn into the ventilation zone may be affected by the shape of the perforations. The cross-sectional shape of the perforations can be seen in a plane parallel to the central axis of the ventilation zone. The central axis of the ventilation zone is preferably the same as the central axis of the entire aerosol-generating article.

Between 5 and 15 perforations may be provided in the ventilation zone. Preferably, between 7 and 14 perforations may be provided in the ventilation zone. Preferably, between 9 and 13 perforations may be provided in the ventilation zone. Preferably, between 10 and 12 perforations may be provided in the ventilation zone. Preferably, the number of perforations is 11.

Having 10 to 12 perforations may improve the mixing of ambient air drawn into the ventilation zone through the perforations with air drawn into the ventilation zone through the strip of aerosol-forming substrate. Such improved mixing may result in improved aerosol generation. Without being bound by any theory, it has been found that a number of perforations of 10 to 12 results in an optimal mixture of ambient air and air carrying the volatilized aerosol-forming substrate. The reason may be that this relatively small number of perforations requires relatively large perforations to enable a sufficient amount of ambient air to be drawn into the ventilation zone. The relatively large perforations may result in relatively strong turbulence between the two gas streams and thus improve mixing of the two gas streams.

The ventilation zone may be arranged in the second hollow tubular section of the aerosol-cooling element. The second hollow tubular section may have a diameter of 130mm ³ And 200mm ³ Preferably between 155mm ³ And 185mm ³ Between them, more preferably 170mm ³ Is provided.

The second hollow tubular section may be a hollow interior portion of the ventilation zone or adjacent the ventilation zone. Air may be drawn through the second hollow tubular section. The second hollow tubular section may be a region where ambient air mixes with air drawn through the strip of aerosol-forming substrate. The second hollow tubular section is preferably a peripheral wall of the ventilation zone.

Perforations may be arranged in the peripheral wall of the ventilation zone. The perforations may have a non-constant pitch with a coefficient of variation of the pitch higher than 5%, preferably higher than 10%, more preferably higher than 15%. The coefficient of variation is the ratio of standard deviation to mean. The non-constant pitch arrangement of perforations may be an arrangement with a pitch having a coefficient of variation of less than 40%, preferably less than 35%, more preferably less than 30%.

In other words, a first pair of adjacent perforations may have a first distance from each other measured along the arc length of the peripheral wall, a second pair of adjacent perforations, different from the first pair, may have a second distance from each other measured along the arc length of the peripheral wall, and a third pair of adjacent perforations, different from the first and second pairs, may have a third distance from each other measured along the arc length of the peripheral wall. The first distance, the second distance, and the third distance may all be different.

In one embodiment, more than half of the perforations may be arranged in one half of the peripheral wall of the ventilation zone, and less than half of the perforations may be arranged in the other half of the peripheral wall of the ventilation zone. In a preferred embodiment, more than two-thirds of the perforations may be arranged in one half of the peripheral wall of the ventilation zone, and less than one-third of the perforations may be arranged in the other half of the peripheral wall of the ventilation zone.

An asymmetric arrangement with perforations may achieve the same mass mixing of ambient air with air drawn through the strip of aerosol-forming substrate. However, the asymmetric arrangement of perforations may be easier to manufacture or may facilitate higher manufacturing speeds. In more detail, it is difficult to increase the manufacturing speed while maintaining the symmetrical arrangement of the perforations with high quality. It has been found that having asymmetrically arranged perforations as described herein does not lead to a reduced quality of air mixing or reduced quality of aerosol generation.

The perforations may perforate the peripheral wall. The perforations may penetrate the peripheral wall.

The peripheral wall may at least partially surround the ventilation zone. The peripheral wall may completely surround the ventilation zone. The peripheral wall of the ventilation zone may facilitate the hollow tubular shape of the ventilation zone. The peripheral wall may abut the surrounding environment around the aerosol-generating article. The peripheral wall may abut the hollow interior of the ventilation zone.

The hollow tubular ventilation zone may have an inner diameter of between 2.5 mm and 7.5 mm, preferably between 3.5 mm and 6.5 mm, more preferably between 4.0 mm and 6.0 mm, more preferably between 4.5 mm and 5.5 mm, most preferably 5.0 mm.

The peripheral wall of the ventilation zone may have a thickness of between 0.8 mm and 2.2 mm, more preferably between 1.2 mm and 1.8 mm, and most preferably about 1.5 mm.

The perforations may be arranged in rows. The perforations may be arranged like pearls on a string. The rows of perforations may be annularly arranged. The rows of perforations may be in an annular arrangement with the center being the central axis of the ventilation zone.

The distance between the perforations of the ventilation zone and the downstream end of the strip of aerosol-generating substrate may be between 1 and 6 mm, preferably between 2 and 5 mm, more preferably between 3 and 4 mm.

The distance between the perforations of the ventilation zone and the downstream end of the aerosol-generating article may be between 10 and 26 mm, preferably between 12 and 24 mm, more preferably between 14 and 22 mm, most preferably between 16 and 20 mm.

The arrangement of perforations in this region of the ventilation zone may improve aerosol generation. Aerosol generation may be improved by placing perforations such that an optimal mixing is achieved between ambient air drawn into the ventilation zone through the perforations and air drawn into the perforations through the strip of aerosol-forming substrate.

The perforations may be configured to allow ambient air to be drawn into the ventilation zone.

The ratio of ambient air drawn into the ventilation zone through the perforations to air drawn into the ventilation zone through the strip of aerosol-forming substrate may be between 5% and 75%, preferably between 20% and 65%, more preferably between 30% and 60%, more preferably between 40% and 55%, most preferably 50%.

Such a ratio may improve aerosol formation by achieving thorough mixing of ambient air and air drawn through the strips of aerosol-forming substrate. Such a ratio may improve aerosol formation by enabling optimal cooling of air drawn through the strip of aerosol-forming substrate due to mixing of this air with ambient air.

The aerosol-generating article may further comprise a filter downstream of the ventilation zoneA mouth section. The suction Resistance (RTD) of the filter segments can be 5 mm H ₂ O and 80 mm H ₂ O, preferably between 10 mm H ₂ O and 65 mm H ₂ O, more preferably between 15 mm H ₂ O and 50 mm H ₂ O, more preferably at 20 mm H ₂ O and 40 mm H ₂ Between O, most preferably 30 mm H ₂ O. In general, ISO 6565:2002 and coresta, one of the methods nr.41 recommended to measure RTD.

The invention further relates to an aerosol-generating system comprising an aerosol-generating device having a cavity for receiving an aerosol-generating article as described herein.

The invention further relates to a method for manufacturing an aerosol-generating article, wherein the method may comprise the steps of:

providing a strip of aerosol-generating substrate;

providing a ventilation zone downstream of the strip of aerosol-generating substrate; and

perforations are created in the peripheral wall of the ventilation zone, wherein each perforation has a central axis, wherein the aerosol-generating article has a central axis, and wherein a minimum distance between the central axis of each perforation and the central axis of the aerosol-generating article is between 3% and 15% of the outer diameter of the aerosol-generating article.

The invention further relates to a method for manufacturing an aerosol-generating article, wherein the method comprises the steps of:

providing a strip of aerosol-generating substrate;

The term "aerosol-generating article" is used herein to refer to articles in which an aerosol-generating substrate is heated to produce and deliver an inhalable aerosol to a consumer. As used herein, the term "aerosol-generating substrate" refers to 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 an aerosol-generating substrate of an aerosol-generating article to generate an aerosol.

As used herein with reference to the present invention, the term "strip" is used to refer to a generally cylindrical element of substantially circular, oval or elliptical cross-section.

As used herein, the term "longitudinal" refers to a direction corresponding to the major longitudinal axis of the aerosol-generating article, which extends between the upstream and downstream ends of the aerosol-generating article. As used herein, the terms "upstream" and "downstream" describe the relative positions of an element or portion of an element of an aerosol-generating article with respect to a direction in which an aerosol is transported through the aerosol-generating article during use.

During use, air is drawn through the aerosol-generating article in the longitudinal direction. The term "transverse" refers to a direction perpendicular to the longitudinal axis. Unless otherwise indicated, any reference to an aerosol-generating article or a "cross-section" of a component of an aerosol-generating article refers to a cross-section.

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 represent the dimension of a strip or elongate tubular section in the longitudinal direction.

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

In certain preferred embodiments, the aerosol-forming substrate comprises a homogenized plant material, preferably a homogenized tobacco material.

As used herein, the term "homogenized plant material" encompasses any plant material formed by agglomeration of plant particles. For example, a sheet or web of homogenized tobacco material for use in an aerosol-forming substrate of the invention may be formed by agglomerating particles of tobacco material obtained by comminuting, grinding or milling plant material and optionally one or more of tobacco lamina and tobacco leaf stems. The homogenized plant material may be produced by casting, extrusion, papermaking processes, or any other suitable process known in the art.

The homogenized plant material may be provided in any suitable form. For example, the homogenized plant material may be in the form of one or more sheets. As used herein with reference to the present invention, the term "sheet" describes a layered element having a width and length substantially greater than its thickness.

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

The homogenized plant material may be in the form of a plurality of strands, ribbons or pieces. As used herein, the term "strand" describes an elongated element material having a length substantially greater than its width and thickness. The term "strand" shall be considered to include strips, chips and any other homogenized plant material having a similar form. The strands of homogenized plant material may be formed from sheets of homogenized plant material, such as by cutting or chopping, or by other methods, such as by extrusion methods.

The tobacco particles can have a nicotine content of at least about 2.5% by weight on a dry weight basis. More preferably, the tobacco particles can have a nicotine content of at least about 3% by weight, even more preferably at least about 3.2% by weight, even more preferably at least about 3.5% by weight, most preferably at least about 4% by weight on a dry weight basis.

The aerosol-forming substrate may further comprise one or more aerosol-forming agents. Upon volatilization, the aerosol-forming agent can deliver other volatilized compounds in the aerosol that are released from the aerosol-forming substrate upon heating, such as nicotine and flavoring agents. Suitable aerosol formers included in homogenized plant material are known in the art and include, but are not limited to: polyols such as triethylene glycol, propylene glycol, 1, 3-butanediol and glycerol; esters of polyols, such as glycerol mono-, di-, or triacetate; and aliphatic esters of mono-, di-or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate.

The aerosol-forming substrate may have an aerosol-former content of between about 5 wt% and about 30 wt% on a dry weight basis, such as between about 10 wt% and about 25 wt% on a dry weight basis, or between about 15 wt% and about 20 wt% on a dry weight basis.

For example, if the substrate is intended for use in an aerosol-generating article of an electrically operated aerosol-generating system having a heating element, it may preferably comprise an aerosol-former content of between about 5% and about 30% by weight on a dry weight basis. If the substrate is intended for use in an aerosol-generating article of an electrically operated aerosol-generating system having a heating element, the aerosol-former is preferably glycerol.

The aerosol-forming substrate may comprise a gel composition comprising an alkaloid compound or a cannabinoid compound, or both an alkaloid compound and a cannabinoid compound. In a particularly preferred embodiment, the aerosol-forming substrate comprises a gel composition comprising nicotine.

Preferably, the gel composition comprises nicotine.

The aerosol-generating article may comprise a substrate wrapper at least partially defining an aerosol-forming substrate. The matrix wrapper may comprise one or more layers of the same length in the longitudinal direction of the aerosol-generating article. The substrate package may have a thickness of between 30 microns and 45 microns. Preferably, however, the matrix wrapper may have a thickness of 50 microns or greater.

The matrix wrapper may have a thickness of 60 microns or greater, preferably 65 microns or greater, more preferably 75 microns or greater, more preferably 80 microns or greater, more preferably 90 microns or greater, more preferably 100 microns or greater, more preferably 110 microns or greater, more preferably 120 microns or greater, more preferably 130 microns or greater, more preferably 140 microns or greater, more preferably 145 microns or greater, more preferably 150 microns or greater. The matrix wrapper may have a thickness of about 148 microns. The substrate package may have a thickness between 143 microns and 153 microns. The matrix wrapper may have a thickness between 140 microns and 160 microns.

The orientation of the perforations according to the invention may be preferred when the tobacco rod is thin (i.e. when the rod of aerosol-forming substrate has a relatively low radial thickness) compared to the outer diameter of the aerosol-generating article. This is particularly the case when the matrix package is thicker (i.e., when the matrix package has a thickness of 50 microns or greater), as described herein. This may be because when the airflow is linear, and the aerosol-generating substrate does not occupy the full diameter of the rod, a different mixing with air from ventilation may be required.

The matrix package may have a density of 800 kilograms per cubic meter or less.

Preferably, in an aerosol-generating article according to the invention, the susceptor is arranged within the strip of aerosol-forming substrate and is in thermal contact with the aerosol-forming substrate. Preferably, the susceptor is an elongate susceptor.

As used herein with reference to the present invention, the term "susceptor" refers to a material that can convert electromagnetic energy into heat. Eddy currents induced in the susceptor when located within the fluctuating electromagnetic field cause heating of the susceptor. When the elongate susceptor position is in thermal contact with the aerosol-forming substrate, the aerosol-forming substrate is heated by the susceptor.

When used to describe a susceptor, the term "elongated" means that the length dimension of the susceptor is greater than its width dimension or its thickness dimension, for example, twice greater than its width dimension or its thickness dimension.

The susceptor is preferably arranged substantially longitudinally within the strip. This means that the length dimension of the elongate susceptor is arranged substantially parallel to the longitudinal direction of the strip, for example within +/-10 degrees of parallel to the longitudinal direction of the strip. In a preferred embodiment, the elongate susceptor may be located at a radially central position within the strip and extend along the longitudinal axis of the strip.

Preferably, the susceptor extends all the way to the downstream end of the strip of aerosol-generating article. In some embodiments, the susceptor may extend all the way to the upstream end of the strip of aerosol-generating article. In a particularly preferred embodiment, the susceptor has substantially the same length as the rod of aerosol-forming substrate and extends from an upstream end of the rod to a downstream end of the rod.

The susceptor is preferably in the form of a needle, a strip or a blade.

The susceptor preferably has a length of about 5 mm to about 15 mm, for example about 6 mm to about 12 mm, or about 8 mm to about 10 mm.

The ratio between the length of the susceptor and the overall length of the aerosol-generating article substrate may be from about 0.2 to about 0.35.

The susceptor may be formed of any material capable of being inductively heated to a temperature sufficient to generate an aerosol from the aerosol-forming substrate. Preferred susceptors comprise metal or carbon.

Preferred susceptors may comprise or consist of ferromagnetic materials, such as ferromagnetic alloys, ferritic iron, or ferromagnetic steel or stainless steel. Suitable susceptors may be or include aluminum. Preferred susceptors may be made of 400 series stainless steel, for example grade 410 or grade 420 or grade 430 stainless steel. When positioned within an electromagnetic field having similar frequency and field strength values, different materials will consume different amounts of energy.

Thus, parameters of the susceptor, such as material type, length, width, and thickness, can be altered within the known electromagnetic field to provide the desired power consumption. The preferred susceptor may be heated to a temperature in excess of 250 degrees celsius.

Suitable susceptors may include a nonmetallic core with a metal layer disposed on the nonmetallic core, such as a metal trace formed on a surface of a ceramic core. The susceptor may have an outer protective layer, such as a ceramic protective layer or a glass protective layer that encapsulates the susceptor. The susceptor may include a protective coating formed of glass, ceramic, or an inert metal formed on a core of susceptor material.

The susceptor is arranged in thermal contact with the aerosol-forming substrate. Thus, when the susceptor is heated, the aerosol-forming substrate is heated and an aerosol is formed. Preferably, the susceptor is arranged in direct physical contact with the aerosol-forming substrate, for example within the aerosol-forming substrate.

The aerosol-generating article may further comprise a downstream section at a location downstream of the strip of aerosol-forming substrate. The downstream section may comprise an intermediate hollow section comprising an aerosol-cooling element arranged in alignment with and downstream of the strip of aerosol-forming substrate.

The downstream section may further comprise one or more downstream elements on top of the aerosol-cooling element. For example, the intermediate hollow section may further comprise a support element positioned immediately downstream of the strip of aerosol-forming substrate, and the aerosol-cooling element may be located between the support element and the downstream end (or mouth end) of the aerosol-generating article. In more detail, the aerosol-cooling element may be positioned immediately downstream of the support element. In some preferred embodiments, the aerosol-cooling element may abut the support element. As will be described below, the downstream section may further include one or more elements on top of the intermediate hollow section at a location downstream of the intermediate hollow section.

The aerosol-cooling element may comprise a hollow tubular section defining a cavity extending from an upstream end of the aerosol-cooling element up to a downstream end of the aerosol-cooling element, and the ventilation zone may be provided at a location along the hollow tubular section.

As used herein, the term "hollow tubular element" is used to refer to a generally elongated element that defines a lumen or airflow path along its longitudinal axis. In particular, the term "tubular" will be used hereinafter to refer to a tubular element having a substantially cylindrical cross section and defining at least one air flow conduit establishing uninterrupted fluid communication between an upstream end of the tubular element and a downstream end of the tubular element. However, it should be understood that alternative geometries (e.g., alternative cross-sectional shapes) of the tubular element may be possible.

In the context of the present invention, a hollow tubular section provides a non-limiting flow passage. This means that the hollow tubular section provides a negligible level of resistance to suction (RTD). Thus, the flow channel should be free of any components that would impede the flow of air in the longitudinal direction. Preferably, the flow channel is substantially empty.

When used in describing an aerosol-cooling element, the term "elongate" means that the aerosol-cooling element has a length dimension that is greater than its width dimension or its diameter dimension, such as twice or more of its width dimension or its diameter dimension.

The inventors have found that satisfactory cooling of an aerosol-stream generated upon heating an aerosol-forming substrate and drawn through one such aerosol-cooling element is achieved by providing a ventilation zone at a location along the hollow tubular section. Furthermore, the inventors have found that, as will be described in more detail below, it is possible to counteract the effect of an increased dilution of the aerosol caused by the admission of ventilation air into the article, in particular by arranging the ventilation zone at a precisely defined position along the length of the aerosol-cooling element, and by preferably utilizing a hollow tubular section having a predetermined peripheral wall thickness or internal volume.

Without wishing to be bound by theory, it is hypothesized that since the temperature of the aerosol flow is rapidly reduced by introducing ventilation air as the aerosol travels towards the mouthpiece segment, ventilation air is admitted into the aerosol flow at a location relatively close to the upstream end of the aerosol-cooling element (i.e. sufficiently close to the susceptor extending within the strip of aerosol-forming substrate, which is the heat source during use), significant cooling of the aerosol flow is achieved, which has a beneficial effect on condensation and nucleation of aerosol particles. Thus, the overall ratio of aerosol particulate phase to aerosol gas phase may be increased as compared to existing non-ventilated aerosol-generating articles.

The aerosol-cooling element is arranged substantially in alignment with the strip. This means that the length dimension of the aerosol-cooling element is arranged substantially parallel to the longitudinal direction of the strip and the article, for example within +/-10 degrees of parallel to the longitudinal direction of the strip. In a preferred embodiment, the aerosol-cooling element extends along the longitudinal axis of the strip. The longitudinal axis of the strip is preferably the same as the longitudinal axis of the aerosol-generating article. The longitudinal axis of the aerosol-generating article is preferably the same as the central axis of the aerosol-generating article.

The aerosol-cooling element preferably has an outer diameter substantially equal to the outer diameter of the strip of aerosol-forming substrate and the outer diameter of the aerosol-generating article.

The aerosol-cooling element may have an outer diameter of between 5 and 12 mm, for example between 5 and 10 mm or between 6 and 8 mm. In a preferred embodiment, the aerosol-cooling element has an outer diameter of 7.2 mm +/-10%.

Preferably, the hollow tubular section of the aerosol-cooling element has an inner diameter of at least about 2 mm. More preferably, the hollow tubular section of the aerosol-cooling element has an inner diameter of at least about 3.5 millimeters. Even more preferably, the hollow tubular section of the aerosol-cooling element has an inner diameter of at least about 5 millimeters.

The peripheral wall of the aerosol-cooling element may have a thickness of less than about 2.5 mm, preferably less than 22 mm. In a particularly preferred embodiment, the peripheral wall of the aerosol-cooling element has a thickness of between 1.2 and 1.8 mm.

In an embodiment, the peripheral wall of the aerosol-cooling element has a thickness of about 1.5 millimeters.

The aerosol-cooling element may have a length of less than about 10 millimeters.

The aerosol-cooling element may have a length of at least about 5 millimeters. Preferably, the aerosol-cooling element has a length of at least about 6 mm, more preferably at least about 7 mm.

The aerosol-cooling element may have a length of about 5 mm to about 10 mm, preferably about 6 mm to about 10 mm, more preferably about 7 mm to about 10 mm.

Thus, the aerosol-cooling element may have a relatively short length compared to aerosol-cooling elements of prior art aerosol-generating articles. Due to the optimized effectiveness of the hollow tubular section forming the aerosol-cooling element in cooling and nucleation of the aerosol, a reduction of the length of the aerosol-cooling element is possible. The reduction in length of the aerosol-cooling element advantageously reduces the risk of deforming the aerosol-generating article due to compression during use, as the aerosol-cooling element generally has a lower resistance to deformation than the mouthpiece. Furthermore, reducing the length of the aerosol-cooling element may provide a cost benefit to the manufacturer, as the cost per unit length of the hollow tubular section is typically higher than the cost of other elements such as the mouthpiece element.

The ratio between the length of the aerosol-cooling element and the length of the strip of aerosol-forming substrate may be from about 0.25 to about 1.

Preferably, the ratio between the length of the aerosol-cooling element and the length of the strip of aerosol-forming substrate is at least about 0.3, more preferably at least about 0.4, even more preferably at least about 0.5. In a preferred embodiment, the ratio between the length of the aerosol-cooling element and the length of the strip of aerosol-forming substrate is less than about 0.9, more preferably less than about 0.8, even more preferably less than about 0.7.

The ratio between the length of the aerosol-cooling element and the length of the strip of aerosol-forming substrate may be from about 0.3 to about 0.9, preferably from about 0.4 to about 0.9, more preferably from about 0.5 to about 0.9. In other embodiments, the ratio between the length of the aerosol-cooling element and the length of the strip of aerosol-forming substrate is from about 0.3 to about 0.8, preferably from about 0.4 to about 0.8, more preferably from about 0.5 to about 0.8. The ratio between the length of the aerosol-cooling element and the length of the strip of aerosol-forming substrate is from about 0.3 to about 0.7, preferably from about 0.4 to about 0.7, more preferably from about 0.5 to about 0.7.

The ratio between the length of the aerosol-cooling element and the length of the strip of aerosol-forming substrate may be about 0.66.

The ratio between the length of the aerosol-cooling element and the overall length of the aerosol-generating article substrate may be from about 0.125 to about 0.375.

Preferably, the ratio between the length of the aerosol-cooling element and the overall length of the aerosol-generating article substrate is at least about 0.13, more preferably at least about 0.14, even more preferably at least about 0.15. The ratio between the length of the aerosol-cooling element and the overall length of the aerosol-generating article substrate is preferably less than about 0.3, more preferably less than about 0.25, even more preferably less than about 0.20.

The ratio between the length of the aerosol-cooling element and the overall length of the aerosol-generating article substrate is preferably from about 0.13 to about 0.3, more preferably from about 0.14 to about 0.3, even more preferably from about 0.15 to about 0.3. In other embodiments, the ratio between the length of the aerosol-cooling element and the overall length of the aerosol-generating article substrate is preferably from about 0.13 to about 0.25, more preferably from about 0.14 to about 0.25, even more preferably from about 0.15 to about 0.25. In further embodiments, the ratio between the length of the aerosol-cooling element and the overall length of the aerosol-generating article substrate is preferably from about 0.13 to about 0.2, more preferably from about 0.14 to about 0.2, even more preferably from about 0.15 to about 0.2.

The ratio between the length of the aerosol-cooling element and the overall length of the aerosol-generating article substrate is about 0.18.

Preferably, the length of the mouthpiece element is at least 1 mm greater than the length of the aerosol-cooling element, more preferably at least 2 mm greater than the length of the aerosol-cooling element, more preferably at least 3 mm greater than the length of the aerosol-cooling element. As described above, the reduced length of the aerosol-cooling element may advantageously allow the length of other elements of the aerosol-generating article (such as the mouthpiece element) to be increased. The foregoing describes potential technical benefits of providing a relatively long mouthpiece element.

Preferably, in an aerosol-generating article according to the invention, the aerosol-cooling element has an average radial stiffness of at least about 80%, more preferably at least about 85%, even more preferably at least about 90%. Thus, the aerosol-cooling element is capable of providing a desired level of hardness to the aerosol-generating article.

If desired, the radial stiffness of the aerosol-cooling element of an aerosol-generating article according to the invention may be further increased by defining the aerosol-cooling element with a rigid rod wrapper, for example a rod wrapper having a basis weight of at least about 80 grams per square meter (gsm), or at least about 100gsm, or at least about 110 gsm.

The aerosol-cooling element may be formed from any suitable material or combination of materials. For example, the aerosol-cooling element may be formed from one or more materials selected from the group consisting of: cellulose acetate, cardboard, curled paper, such as curled heat resistant paper or curled parchment, and polymeric materials, such as Low Density Polyethylene (LDPE). Other suitable materials include Polyhydroxyalkanoate (PHA) fibers.

In a preferred embodiment, the aerosol-cooling element is formed from cellulose acetate.

The ventilation zone includes a plurality of perforations through the peripheral wall of the aerosol-cooling element. Preferably, the ventilation zone comprises at least one row of circumferential perforations. In some embodiments, the vented zone may include two circumferential rows of perforations. For example, perforations may be formed on the production line during manufacture of the aerosol-generating article. Preferably, each row of circumferential perforations comprises 8 to 30 perforations. However, it has been found that a certain number of perforations, 5 to 15 perforations, 7 to 14 perforations, 9 to 13 perforations, 10 to 12 perforations, in particular a number of 11 perforations, results in improved aerosol generation.

Where the aerosol-generating article comprises a composite mandrel for securing the aerosol-cooling element to one or more of the other components of the aerosol-generating article, the ventilation zone preferably comprises at least one row of corresponding circumferential perforations provided through a portion of the composite mandrel package. These may be formed on a production line during manufacture of the smoking article. Preferably, the one or more circumferential perforations provided by combining a portion of the mandrel package are substantially aligned with the one or more rows of perforations through the peripheral wall of the aerosol-cooling element. In some embodiments, the distance between the ventilation zone and the upstream end of the hollow tubular section of the aerosol-cooling element is at least about 1 millimeter. Preferably, the distance between the ventilation zone and the upstream end of the hollow tubular section of the aerosol-cooling element is at least about 2 mm. More preferably, the distance between the ventilation zone and the upstream end of the hollow tubular section of the aerosol-cooling element is at least about 3 mm.

In some embodiments, the distance between the ventilation zone and the upstream end of the hollow tubular section of the aerosol-cooling element is less than or equal to about 6 millimeters. Preferably, the distance between the ventilation zone and the upstream end of the hollow tubular section of the aerosol-cooling element is less than or equal to about 5 mm. More preferably, the distance between the ventilation zone and the upstream end of the hollow tubular section of the aerosol-cooling element is less than or equal to about 4 millimeters.

The distance between the ventilation zone and the mouth end of the aerosol-generating article is preferably at least about 10 mm. More preferably, the distance between the ventilation zone and the mouth end of the aerosol-generating article is at least about 12 mm. Even more preferably, the distance between the ventilation zone and the mouth end of the aerosol-generating article is at least about 16 mm.

The distance between the ventilation zone and the mouth end of the aerosol-generating article is preferably less than or equal to about 26 mm. More preferably, the distance between the ventilation zone and the mouth end of the aerosol-generating article is less than or equal to about 24 mm. Even more preferably, the distance between the ventilation zone and the mouth end of the aerosol-generating article is less than or equal to about 22 mm. In particularly preferred embodiments, the distance between the ventilation zone and the mouth end of the aerosol-generating article is less than or equal to about 20 millimeters.

The distance between the ventilation zone and the upstream end of the downstream section is preferably at least about 6 mm. More preferably, the distance between the ventilation zone and the upstream end of the downstream section is at least about 8 millimeters. Even more preferably, the distance between the ventilation zone and the upstream end of the downstream section is at least about 10 millimeters.

The distance between the ventilation zone and the upstream end of the downstream section is preferably less than or equal to about 20 millimeters. More preferably, the distance between the ventilation zone and the upstream end of the downstream section is less than or equal to about 18 millimeters. Even more preferably, the distance between the ventilation zone and the upstream end of the downstream section is less than or equal to about 16 millimeters.

The distance between the ventilation zone and the downstream end of the susceptor is preferably at least about 6 mm. More preferably, the distance between the ventilation zone and the downstream end of the susceptor is at least about 8 millimeters. Even more preferably, the distance between the ventilation zone and the downstream end of the susceptor is at least about 10 millimeters.

The distance between the ventilation zone and the downstream end of the susceptor may be between 9 mm and 10 mm.

The distance between the ventilation zone and the downstream end of the aerosol-forming substrate may be between 9 and 10 mm.

The distance between the ventilation zone and the downstream end of the susceptor is preferably less than or equal to about 20 mm. More preferably, the distance between the ventilation zone and the downstream end of the susceptor is less than or equal to about 18 millimeters. Even more preferably, the distance between the ventilation zone and the downstream end of the susceptor is less than or equal to about 16 millimeters.

The aerosol-generating article according to the invention may have a ventilation level of at least about 5%. The term "ventilation level" may also be expressed as "ventilation percentage".

Throughout the present specification, the term "ventilation level" is used to denote the volume ratio between the air flow (ventilation air flow) entering the aerosol-generating article via the ventilation zone and the sum of the aerosol air flow and the ventilation air flow. The greater the ventilation level, the higher the dilution of the aerosol stream delivered to the consumer.

Preferably, the aerosol-generating article according to the invention may have a ventilation level of at least about 10%, preferably at least about 15%, more preferably at least about 20%, more preferably at least about 30%, most preferably at least about 40%. In a particularly preferred embodiment, the aerosol-generating article according to the invention has a ventilation level of at least about 25%.

The aerosol-generating article preferably has a ventilation level of less than about 75%, preferably less than about 65%, more preferably less than about 60%.

The aerosol-generating article according to the invention preferably has a ventilation level of less than or equal to about 45%. More preferably, the aerosol-generating article according to the invention has a ventilation level of less than or equal to about 40%, even more preferably less than or equal to about 35%.

In a particularly preferred embodiment, the aerosol-generating article has a ventilation level of about 30%.

In particularly preferred embodiments, the aerosol-generating article has a ventilation level of from about 28% to about 42%. In some particularly preferred embodiments, the aerosol-generating article has a ventilation level of about 30%.

Without wishing to be bound by theory, the inventors have found that the temperature drop caused by cooler external air entering the hollow tubular section via the ventilation zone can have a beneficial effect on the nucleation and growth of aerosol particles.

The formation of aerosols from gas mixtures containing various chemicals depends on subtle interactions between nucleation, evaporation and condensation and coalescence, taking into account variations in vapor concentration, temperature and velocity fields. The so-called classical nucleation theory is based on the following assumptions: a portion of the molecules in the gas phase are large enough to remain coherent for a long time with sufficient probability (e.g., half probability). These molecules represent some kind of critical, threshold molecular clusters in transient molecular aggregates, which means that on average smaller molecular clusters may quickly break down into the gas phase, while larger clusters may grow on average. Such critical clusters are considered critical nucleation cores from which droplets are expected to grow due to condensation of molecules in the vapor. Assuming that the original droplets just nucleated appear at a certain original diameter, then may grow by several orders of magnitude. This process is promoted and enhanced by the rapid cooling of the surrounding steam to cause condensation. In this regard, it should be remembered that evaporation and condensation are two aspects of the same mechanism, namely gas-liquid mass transfer. While evaporation involves a net mass transfer from the liquid droplet to the gas phase, condensation is a net mass transfer from the gas phase to the liquid droplet phase. Evaporation (or condensation) will cause the droplets to contract (or grow) without changing the number of droplets.

In this scenario, which may be more complicated by coalescence phenomena, the temperature and rate of cooling play a critical role in determining how the system responds. Generally, different cooling rates can result in significantly different time behaviors associated with liquid phase (droplet) formation, as the nucleation process is generally nonlinear. Without wishing to be bound by theory, it is hypothesized that cooling may result in a rapid increase in the number concentration of droplets followed by a strong, short increase in this growth (nucleation burst). This nucleation burst appears to be more pronounced at lower temperatures. Furthermore, it appears that a higher cooling rate may be advantageous for an earlier onset of nucleation. In contrast, a decrease in the cooling rate appears to have a beneficial effect on the final size of the aerosol droplets eventually reached.

Thus, the rapid cooling caused by the external air entering the hollow tubular section via the ventilation zone can be advantageously used to promote nucleation and growth of aerosol droplets. At the same time, however, the entry of external air into the hollow tubular section has the direct disadvantage of diluting the aerosol flow delivered to the consumer.

The inventors have surprisingly found that when the ventilation level is within the above-mentioned range, the dilution effect on the aerosol (which can be assessed in particular by measuring the effect on the delivery of an aerosol-forming agent (such as glycerol) included in the aerosol-forming substrate) is advantageously minimised. In particular, ventilation levels between 20% and 70%, preferably between 25% and 50%, and even more preferably between 28% and 42% have been found to result in particularly satisfactory glycerol delivery values. At the same time, the degree of nucleation and thus the delivery of nicotine and aerosol former (e.g. glycerol) is increased.

The inventors have surprisingly found how the beneficial effect of enhanced nucleation, promoted by rapid cooling induced by introducing ventilation air into the article, can significantly offset the less desirable dilution effect. Thus, satisfactory aerosol delivery values are consistently achieved with the aerosol-generating article according to the invention.

This is particularly advantageous for "short" aerosol-generating articles, for example wherein the length of the strips of aerosol-forming substrate is less than about 40 mm, preferably less than 25 mm, even more preferably less than 20 mm, or wherein the overall length of the aerosol-generating article is less than about 70 mm, preferably less than about 60 mm, even more preferably less than 50 mm. As will be appreciated, in such aerosol-generating articles, little time and space is available for aerosol formation and particulate phase of the aerosol to become available for delivery to the consumer.

Furthermore, because the ventilated hollow tubular element does not substantially contribute to the overall RTD of the aerosol-generating article, in an aerosol-generating article according to the invention, the overall RTD of the article can advantageously be fine-tuned by adjusting the length and density of the strip of aerosol-forming substrate, and optionally the length and density of the segments of filter material forming part of the mouthpiece, or the length and density of the segments of filter material provided upstream of the aerosol-forming substrate and the susceptor. Thus, an aerosol-generating article having a predetermined RTD can be consistently and highly accurately manufactured so that a satisfactory RTD level can be provided to the consumer even in the presence of ventilation.

In the aerosol-generating article according to the invention, the overall RTD of the article is substantially dependent on the RTD of the rod and optionally on the RTD of the mouthpiece and/or the upstream rod. This is because the hollow tubular sections of the aerosol-cooling element and the hollow tubular sections of the support element are substantially empty and thus contribute substantially only slightly to the overall RTD of the aerosol-generating article.

Indeed, the hollow tubular section of the aerosol-cooling element may be adapted to be generated at about 0 mm H ₂ O (about 0 Pa) to about 20 mm H ₂ RTD in the range of O (about 200 Pa). Preferably, the hollow tubular section of the aerosol-cooling element is adapted to generate about 0 mm H ₂ O (about 0 Pa) and about 10 mm H ₂ RTD between O (about 100 Pa).

The downstream section of the aerosol-generating article according to the invention preferably comprises an intermediate hollow section comprising a support element arranged in alignment with and downstream of the strip of aerosol-forming substrate. In particular, the support element may be located immediately downstream of the strip of aerosol-forming substrate and may abut the strip of aerosol-forming substrate.

The support element may be formed from any suitable material or combination of materials. For example, the support element may be formed from one or more materials selected from the group consisting of: cellulose acetate, cardboard, curled papers, such as curled heat resistant papers or curled parchment papers, and polymeric materials, such as Low Density Polyethylene (LDPE). In a preferred embodiment, the support element is formed from cellulose acetate. Other suitable materials include Polyhydroxyalkanoate (PHA) fibers.

The support element may comprise a hollow tubular element. In a preferred embodiment, the support element comprises a hollow cellulose acetate tube.

The support elements are arranged substantially in alignment with the bars. This means that the length dimension of the support elements is arranged substantially parallel to the longitudinal direction of the strip and the article, for example within +/-10 degrees of parallel to the longitudinal direction of the strip. In a preferred embodiment, the support element extends along the longitudinal axis of the strip.

The support element preferably has an outer diameter substantially equal to the outer diameter of the strip of aerosol-forming substrate and the outer diameter of the aerosol-generating article.

The support element may have an outer diameter of between 5 and 12 mm, for example between 5 and 10 mm or between 6 and 8 mm. In a preferred embodiment, the support element has an outer diameter of 7.2 mm +/-10%. The support element may have a length of between 5 mm and 15 mm. In a preferred embodiment, the support element has a length of 8 mm.

The peripheral wall of the support element may have a thickness of at least 1 mm, preferably at least about 1.5 mm, more preferably at least about 2 mm.

The support element may have a length of between about 5 millimeters and about 15 millimeters.

Preferably, the support element has a length of at least about 6 mm, more preferably at least about 7 mm.

In a preferred embodiment, the support element has a length of less than about 12 millimeters, more preferably less than about 10 millimeters.

In some embodiments, the support element has a length of about 5 millimeters to about 15 millimeters, preferably about 6 millimeters to about 15 millimeters, more preferably about 7 millimeters to about 15 millimeters. In other embodiments, the support element has a length of about 5 millimeters to about 12 millimeters, preferably about 6 millimeters to about 12 millimeters, more preferably about 7 millimeters to about 12 millimeters. In further embodiments, the support element has a length of about 5 millimeters to about 10 millimeters, preferably about 6 millimeters to about 10 millimeters, more preferably about 7 millimeters to about 10 millimeters.

In a preferred embodiment, the support element has a length of about 8 millimeters.

The ratio of the length of the support element to the length of the strip of aerosol-forming substrate may be from about 0.25 to about 1.

Preferably, the ratio between the length of the support element and the length of the strip of aerosol-forming substrate is at least about 0.3, more preferably at least about 0.4, even more preferably at least about 0.5. In a preferred embodiment, the ratio between the length of the support element and the length of the strip of aerosol-forming substrate is less than about 0.9, more preferably less than about 0.8, even more preferably less than about 0.7.

In some embodiments, the ratio between the length of the support element and the length of the strip of aerosol-forming substrate is from about 0.3 to about 0.9, preferably from about 0.4 to about 0.9, more preferably from about 0.5 to about 0.9. In other embodiments, the ratio between the length of the support element and the length of the strip of aerosol-forming substrate is from about 0.3 to about 0.8, preferably from about 0.4 to about 0.8, more preferably from about 0.5 to about 0.8. In further embodiments, the ratio between the length of the support element and the length of the strip of aerosol-forming substrate is from about 0.3 to about 0.7, preferably from about 0.4 to about 0.7, more preferably from about 0.5 to about 0.7.

In a particularly preferred embodiment, the ratio between the length of the support element and the length of the strip of aerosol-forming substrate is about 0.66.

The ratio between the length of the support element and the overall length of the aerosol-generating article substrate may be from about 0.125 to about 0.375.

Preferably, the ratio between the length of the support element and the overall length of the aerosol-generating article substrate is at least about 0.13, more preferably at least about 0.14, even more preferably at least about 0.15. The ratio between the length of the support element and the overall length of the aerosol-generating article substrate is preferably less than about 0.3, more preferably less than about 0.25, even more preferably less than about 0.20.

In some embodiments, the ratio between the length of the support element and the overall length of the aerosol-generating article substrate is preferably from about 0.13 to about 0.3, more preferably from about 0.14 to about 0.3, more preferably from about 0.15 to about 0.3. In other embodiments, the ratio between the length of the support element and the overall length of the aerosol-generating article substrate is preferably from about 0.13 to about 0.25, more preferably from about 0.14 to about 0.25, even more preferably from about 0.15 to about 0.25. In further embodiments, the ratio between the length of the support element and the overall length of the aerosol-generating article substrate is preferably from about 0.13 to about 0.2, more preferably from about 0.14 to about 0.2, even more preferably from about 0.15 to about 0.2.

In a particularly preferred embodiment, the ratio between the length of the support element and the overall length of the aerosol-generating article substrate is about 0.18.

Preferably, in an aerosol-generating article according to the invention, the support element has an average radial stiffness of at least about 80%, more preferably at least about 85%, even more preferably at least about 90%. Thus, the support element is capable of providing a desired level of hardness to the aerosol-generating article.

If desired, the radial stiffness of the support element of the aerosol-generating article according to the invention may be further increased by defining the support element with a rigid mandrel wrapper, for example a mandrel wrapper having a basis weight of at least about 80 grams per square meter (gsm), or at least about 100gsm, or at least about 110 gsm.

During insertion of an aerosol-generating article according to the invention into an aerosol-generating device to heat an aerosol-forming substrate, a user may need to apply some force in order to overcome the resistance of the aerosol-forming substrate of the aerosol-generating article to insertion. This may damage one or both of the aerosol-generating article and the aerosol-generating device. Additionally, forces applied during insertion of the aerosol-generating article into the aerosol-generating device may displace the aerosol-forming substrate within the aerosol-generating article. This may lead to a heating element of the aerosol-generating device not being properly aligned with the susceptor provided within the aerosol-forming substrate, which may lead to uneven and inefficient heating of the aerosol-forming substrate of the aerosol-generating article. The support element is advantageously configured to prevent downstream movement of the aerosol-forming substrate during insertion of the article into the aerosol-generating device.

Indeed, the hollow tubular section of the support element may be adapted to be produced at about 0 mm H ₂ O (about 0 Pa) to about 20 mm H ₂ RTD in the range of O (about 200 Pa). Preferably, the hollow tubular section of the support element is adapted to generate about 0 mm H ₂ O (about 0 Pa) and about 10 mm H ₂ RTD between O (about 100 Pa).

Wherein the downstream section comprises: in some embodiments, including both a support element comprising a first hollow tubular section and an aerosol-cooling element comprising a second hollow tubular section such that the support element and the aerosol-cooling element together define an intermediate hollow section, the inner diameter (D _STS ) Preferably greater than the inner diameter (D _FTS )。

In more detail, the inner diameter (D _STS ) With the inner diameter (D) of the first hollow tubular section _FTS ) The ratio therebetween is preferably at least about 1.25. More preferably, the inner diameter (D _STS ) With the inner diameter (D) of the first hollow tubular section _FTS ) The ratio therebetween is preferably at least about 1.3. Even more preferably, the inner diameter (D _STS ) With the inner diameter (D) of the first hollow tubular section _FTS ) The ratio therebetween is preferably at least about 1.4. In a particularly preferred embodiment, the inner diameter (D _STS ) With the inner diameter (D) of the first hollow tubular section _FTS ) The ratio therebetween is at least about 1.5, more preferably at least about 1.6.

The inner diameter (D) _STS ) With the inner diameter (D) of the first hollow tubular section _FTS ) The ratio therebetween is preferably less than or equal to about 2.5. More preferably, the inner diameter (D _STS ) With the inner diameter (D) of the first hollow tubular section _FTS ) The ratio therebetween is preferably less than or equal to about 2.25. Even more preferably, the inner diameter (D _STS ) With the inner diameter (D) of the first hollow tubular section _FTS ) The ratio therebetween is preferably less than or equal to about 2.

Wherein the article further comprises a first layer disposed longitudinally within the aerosol-forming substrateIn those embodiments of the elongate susceptor of (a), the inner diameter (D _FTS ) The ratio to the width of the susceptor is preferably at least about 0.2. More preferably, the inner diameter (D _FTS ) The ratio to the width of the susceptor is at least about 0.3. Even more preferably, the inner diameter (D _FTS ) The ratio to the width of the susceptor is at least about 0.4.

Additionally or alternatively, an inner diameter (D _STS ) The ratio to the width of the susceptor is preferably at least about 0.2. More preferably, the inner diameter (D _STS ) The ratio to the width of the susceptor is at least about 0.5. Even more preferably, the inner diameter (D _STS ) The ratio to the width of the susceptor is at least about 0.8.

Preferably, the ratio between the volume of the lumen of the first hollow tubular section and the volume of the lumen of the second hollow tubular section is at least about 0.1. More preferably, the ratio between the volume of the lumen of the first hollow tubular section and the volume of the lumen of the second hollow tubular section is at least about 0.2. Even more preferably, the ratio between the volume of the lumen of the first hollow tubular section and the volume of the lumen of the second hollow tubular section is at least about 0.3.

The ratio between the volume of the lumen of the first hollow tubular section and the volume of the lumen of the second hollow tubular section is preferably less than or equal to about 0.9. More preferably, the ratio between the volume of the lumen of the first hollow tubular section and the volume of the lumen of the second hollow tubular section is preferably less than or equal to about 0.7. Even more preferably, the ratio between the volume of the lumen of the first hollow tubular section and the volume of the lumen of the second hollow tubular section is preferably less than or equal to about 0.5.

In a preferred embodiment, the downstream section of the aerosol-generating article according to the invention comprises an intermediate hollow section having both an aerosol-cooling element as described above and a support element as described above.

Preferably, the length of the mouthpiece element is at least 0.4 times the overall length of the intermediate hollow section, more preferably at least 0.5 times the length of the intermediate hollow section, more preferably at least 0.6 times the length of the intermediate hollow section, more preferably at least 0.7 times the length of the intermediate hollow section.

The downstream section of the aerosol-generating article of the invention preferably comprises a mouthpiece element. The mouthpiece element may preferably be located at the downstream or mouth end of the aerosol-generating article. The mouthpiece element preferably comprises at least one mouthpiece filter segment for filtering aerosol generated by the aerosol-forming substrate. For example, the mouthpiece element may comprise one or more segments of fibrous filter material. Suitable fibrous filter materials will be known to the skilled person. Particularly preferably, the at least one mouthpiece filter segment comprises a cellulose acetate filter segment formed from cellulose acetate tow.

In certain preferred embodiments, the mouthpiece element is comprised of a single mouthpiece filter segment. In an alternative embodiment, the mouthpiece element comprises two or more mouthpiece filter segments axially aligned with each other in abutting end-to-end relationship.

In certain embodiments of the invention, the downstream section may comprise an oral cavity at the downstream end of the mouthpiece element downstream as described above. The mouth end cavity may be defined by a hollow tubular element provided at the downstream end of the mouthpiece. Alternatively, the mouth end cavity may be defined by an outer wrapper of the mouthpiece element, wherein the outer wrapper extends from the mouthpiece element in the downstream direction.

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

In the aerosol-generating article according to the invention, the mouthpiece element forms part of the downstream section and is thus located downstream of the strip of aerosol-forming substrate.

In certain preferred embodiments, the downstream section of the aerosol-generating article further comprises a support element located immediately downstream of the strip of aerosol-forming substrate. The mouthpiece element is located downstream of the support element. Preferably, the downstream section further comprises an aerosol-cooling element located immediately downstream of the support element. The mouthpiece element is preferably located downstream of both the support element and the aerosol-cooling element. Particularly preferably, the mouthpiece element is located immediately downstream of the aerosol-cooling element. For example, the mouthpiece element may abut the downstream end of the aerosol-cooling element.

Preferably, the mouthpiece element has a low particulate filtration efficiency.

Preferably, the mouthpiece is formed from segments of fibrous filter material.

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

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

Preferably, the mouthpiece element has a length of less than about 25 mm H ₂ RTD of O. More preferably, the mouthpiece element has a length of less than about 20 mm H ₂ RTD of O. Even more preferably, the mouthpiece element has a H of less than about 15 mm ₂ RTD of O.

About 10 mm H ₂ O to about 15 mm H ₂ The RTD value of O is particularly preferred because a mouthpiece element having one such RTD is expected to have minimal contribution to the overall RTD of the aerosol-generating article, with substantially no filtering effect on the aerosol delivered to the consumer.

Preferably, the mouthpiece element has an outer diameter substantially equal to the outer diameter of the aerosol-generating article. The mouthpiece element may have an outer diameter of between about 5 mm and about 10 mm, or between about 6 mm and about 8 mm. In a preferred embodiment, the mouthpiece element has an outer diameter of about 7.2 mm.

The mouthpiece element preferably has a length of at least about 5 mm, more preferably at least about 8 mm, even more preferably at least about 10 mm. Alternatively or additionally, the mouthpiece element preferably has a length of less than about 25 mm, more preferably less than about 20 mm, more preferably less than about 15 mm.

In some embodiments, the mouthpiece element preferably has a length of about 5 mm to about 25 mm, more preferably about 8 mm to about 25 mm, even more preferably about 10 mm to about 25 mm. In other embodiments, the mouthpiece element preferably has a length of about 5 mm to about 10 mm, more preferably about 8 mm to about 20 mm, even more preferably about 10 mm to about 20 mm. In further embodiments, the mouthpiece element preferably has a length of about 5 mm to about 15 mm, more preferably about 8 mm to about 15 mm, even more preferably about 10 mm to about 15 mm.

For example, the mouthpiece element may have a length of between about 5 mm and about 25 mm, or between about 8 mm and about 20 mm, or between about 10 mm and about 15 mm. In a preferred embodiment, the mouthpiece element has a length of about 12 mm.

In certain preferred embodiments of the invention, the mouthpiece element has a length of at least 10 mm. Thus, in such embodiments, the mouthpiece element is relatively long compared to the mouthpiece element provided in prior art articles. Providing a relatively long mouthpiece element in the aerosol-generating article of the present invention may provide several benefits to the consumer. The mouthpiece element is generally more resilient to deformation or better adapted to resume its original shape after deformation than other elements (such as an aerosol-cooling element or a support element) which may be provided downstream of the strip of aerosol-forming substrate. Thus, it was found that increasing the length of the mouthpiece element provides improved gripping by the consumer and facilitates insertion of the aerosol-generating article into the heating device. Longer mouthpieces may additionally be used to provide higher filtration levels and to remove undesirable aerosol components, such as phenol, so that higher quality aerosols may be delivered. In addition, the use of longer mouthpiece elements enables more complex mouthpieces to be provided, as there is more space for incorporating mouthpiece components such as capsules, threads and limiters.

In a particularly preferred embodiment of the invention, a mouthpiece having a length of at least 10 mm is combined with a relatively short aerosol-cooling element, for example an aerosol-cooling element having a length of less than 10 mm. This combination has been found to provide a more rigid mouthpiece which reduces the risk of deformation of the aerosol-cooling element during use and assists in a more efficient pumping action by the consumer.

The ratio between the length of the mouthpiece element and the length of the strip of aerosol-forming substrate may be from about 0.5 to about 1.5.

Preferably, the ratio between the length of the mouthpiece element and the length of the strip of aerosol-forming substrate is at least about 0.6, more preferably at least about 0.7, even more preferably at least about 0.8. In a preferred embodiment, the ratio between the length of the mouthpiece element and the length of the strip of aerosol-forming substrate is less than about 1.4, more preferably less than about 1.3, even more preferably less than about 1.2.

In some embodiments, the ratio between the length of the mouthpiece element and the length of the strip of aerosol-forming substrate is from about 0.6 to about 1.4, preferably from about 0.7 to about 1.4, more preferably from about 0.8 to about 1.4. In other embodiments, the ratio between the length of the mouthpiece element and the length of the strip of aerosol-forming substrate is from about 0.6 to about 1.3, preferably from about 0.7 to about 1.3, more preferably from about 0.8 to about 1.3. In further embodiments, the ratio between the length of the mouthpiece element and the length of the strip of aerosol-forming substrate is from about 0.6 to about 1.2, preferably from about 0.7 to about 1.2, more preferably from about 0.8 to about 1.2.

In a particularly preferred embodiment, the ratio between the length of the mouthpiece element and the length of the strip of aerosol-forming substrate is about 1.

The ratio between the length of the mouthpiece element and the overall length of the aerosol-generating article substrate may be from about 0.2 to about 0.35.

Preferably, the ratio between the length of the mouthpiece element and the overall length of the aerosol-generating article substrate is at least about 0.22, more preferably at least about 0.24, even more preferably at least about 0.26. The ratio between the length of the mouthpiece element and the overall length of the aerosol-generating article substrate is preferably less than about 0.34, more preferably less than about 0.32, even more preferably less than about 0.3.

In some embodiments, the ratio between the length of the mouthpiece element and the overall length of the aerosol-generating article substrate is preferably from about 0.22 to about 0.34, more preferably from about 0.24 to about 0.34, even more preferably from about 0.26 to about 0.34. In other embodiments, the ratio between the length of the mouthpiece element and the overall length of the aerosol-generating article substrate is preferably from about 0.22 to about 0.32, more preferably from about 0.24 to about 0.32, even more preferably from about 0.26 to about 0.32. In further embodiments, the ratio between the length of the mouthpiece element and the overall length of the aerosol-generating article substrate is preferably from about 0.22 to about 0.3, more preferably from about 0.24 to about 0.3, even more preferably from about 0.26 to about 0.3.

In a particularly preferred embodiment, the ratio between the length of the mouthpiece element and the overall length of the aerosol-generating article substrate is about 0.27.

The aerosol-generating article may further comprise an upstream section located at a position upstream of the strip of aerosol-forming substrate. The upstream section may include one or more upstream elements. In some embodiments, the upstream section may comprise an upstream element arranged immediately upstream of the strip of aerosol-forming substrate.

Preferably, the aerosol-generating article of the invention may comprise an upstream element located upstream of and adjacent to the aerosol-forming substrate, wherein the upstream section comprises at least one upstream element. The upstream element advantageously prevents direct physical contact with the upstream end of the aerosol-forming substrate. In particular, in case the aerosol-forming substrate comprises a susceptor element, the upstream element may prevent direct physical contact with the upstream end of the susceptor element. This helps to prevent the susceptor element from being dislodged or deformed during handling or transport of the aerosol-generating article. This in turn helps to fix the form and position of the susceptor element. Furthermore, the presence of the upstream element helps to prevent any loss of the substrate, which may be advantageous, for example, if the substrate contains particulate plant material.

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

The upstream element may be a porous rod element. Preferably, the porous rod element does not alter the resistance to draw of the aerosol-generating article. Preferably, the upstream element has a porosity of at least about 50% in the longitudinal direction of the aerosol-generating article. More preferably, the upstream element has a porosity in the longitudinal direction of between about 50% and about 90%. The porosity of the upstream element in the longitudinal direction is defined by the ratio of the cross-sectional area of the material forming the upstream element to the internal cross-sectional area of the aerosol-generating article at the location of the upstream element.

The upstream element may be made of a porous material or may include a plurality of openings. This may be achieved, for example, by laser perforation. Preferably, the plurality of openings are homogeneously distributed over the cross section of the upstream element.

The porosity or permeability of the upstream element may advantageously be varied in order to provide a desired overall resistance to draw of the aerosol-generating article.

Preferably, the RTD of the upstream element is at least about 5 millimeters H ₂ O. More preferably, the RTD of the upstream element is at least about 10 millimeters H ₂ O. Even more preferably, the RTD of the upstream element is at least about 15 millimeters H ₂ O. In particularly preferred embodiments, the RTD of the upstream element is at least about 20 millimeters H ₂ O。

The RTD of the upstream element is preferably less than or equal to about 80 millimeters H ₂ O. More preferably, the upstream element has an RTD of less than or equal to about 60 millimeters H ₂ O. Even more preferably, the RTD of the upstream element is less than or equal to about 40 millimeters H ₂ O。

In some embodiments, the RTD of the upstream element is about 5 millimeters H ₂ O to about 80 mm H ₂ O, preferably about 10 mm H ₂ O to about 80 mm H ₂ O, more preferably about 15 mm H ₂ O to about 80 mm H ₂ O, even more preferably about 20 mm H ₂ O to about 80 mm H ₂ O. In other embodiments, the RTD of the upstream element is about 5 millimeters H ₂ O to about 60 mm H ₂ O, preferably about 10 mm H ₂ O to about 60 mm H ₂ O, more preferably about 15 mm H ₂ O to about 60 mm H ₂ O, even more preferably about 20 mm H ₂ O to about 60 mm H ₂ O. In further embodiments, the RTD of the upstream element is about 5 millimeters H ₂ O to about 40 mmH ₂ O, preferably about 10 mm H ₂ O to about 40 mm H ₂ O, more preferably about 15 mm H ₂ O to about 40 mm H ₂ O, even more preferably about 20 mm H ₂ O to about 40 mm H ₂ O。

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

The upstream element may be made of any material suitable for use in aerosol-generating articles. The upstream element may for example be made of the same material as one of the other components for the aerosol-generating article (e.g. mouthpiece, cooling element or support element). Suitable materials for forming the upstream element include filter materials, ceramics, polymeric materials, cellulose acetate, cardboard, zeolites, or aerosol-forming substrates. Preferably, the upstream element is formed from a cellulose acetate rod.

Preferably, the upstream element is formed of a heat resistant material. For example, it is preferred that the upstream element is formed of a material that resists temperatures up to 350 degrees celsius. This ensures that the upstream element is not adversely affected by the heating means used to heat the aerosol-forming substrate.

Preferably, the diameter of the upstream element is substantially equal to the diameter of the aerosol-generating article.

Preferably, the upstream element has a length of between about 1 mm and about 10 mm, preferably between about 3 mm and about 8 mm, more preferably between about 4 mm and about 6 mm. In a particularly preferred embodiment, the upstream element has a length of about 5 mm. The length of the upstream element may advantageously be varied in order to provide a desired overall length of the aerosol-generating article. For example, where it is desired to reduce the length of one of the other components of the aerosol-generating article, the length of the upstream element may be increased so as to maintain the same overall length of the article.

The upstream element preferably has a substantially homogeneous structure. For example, the upstream elements may be substantially homogeneous in texture and appearance. The upstream element may for example have a continuous regular surface over its entire cross-section. For example, the upstream element may have no discernable symmetry.

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

The aerosol-generating article may have a length of about 35 mm to about 100 mm.

Preferably, the overall length of the aerosol-generating article according to the invention is at least about 38 mm. More preferably, the overall length of the aerosol-generating article according to the invention is at least about 40 mm. Even more preferably, the overall length of the aerosol-generating article according to the invention is at least about 42 mm.

The overall length of the aerosol-generating article according to the invention is preferably less than or equal to 70 mm. More preferably, the overall length of the aerosol-generating article according to the invention is preferably less than or equal to 60 mm. Even more preferably, the overall length of the aerosol-generating article according to the invention is preferably less than or equal to 50 mm.

In some embodiments, the overall length of the aerosol-generating article is preferably from about 38 mm to about 70 mm, more preferably from about 40 mm to about 70 mm, and even more preferably from about 42 mm to about 70 mm. In other embodiments, the overall length of the aerosol-generating article is preferably from about 38 mm to about 60 mm, more preferably from about 40 mm to about 60 mm, and even more preferably from about 42 mm to about 60 mm. In further embodiments, the overall length of the aerosol-generating article is preferably from about 38 mm to about 50 mm, more preferably from about 40 mm to about 50 mm, and even more preferably from about 42 mm to about 50 mm. In an exemplary embodiment, the overall length of the aerosol-generating article is about 45 millimeters.

The aerosol-generating article has an outer diameter of at least 5 millimeters. Preferably, the aerosol-generating article has an outer diameter of at least 6 mm. More preferably, the aerosol-generating article has an outer diameter of at least 7 mm.

Preferably, the aerosol-generating article has an outer diameter of less than or equal to about 12 millimeters. More preferably, the aerosol-generating article has an outer diameter of less than or equal to about 10 millimeters. Even more preferably, the aerosol-generating article has an outer diameter of less than or equal to about 8 millimeters.

In some embodiments, the aerosol-generating article has an outer diameter of about 5 millimeters to about 12 millimeters, preferably about 6 millimeters to about 12 millimeters, more preferably about 7 millimeters to about 12 millimeters. In other embodiments, the aerosol-generating article has an outer diameter of from about 5 mm to about 10 mm, preferably from about 6 mm to about 10 mm, more preferably from about 7 mm to about 10 mm. In further embodiments, the aerosol-generating article has an outer diameter of from about 5 mm to about 8 mm, preferably from about 6 mm to about 8 mm, more preferably from about 7 mm to about 8 mm.

In certain preferred embodiments of the invention, the diameter (D _ME ) Preferably greater than the diameter (D) of the aerosol-generating article at the distal end _DE ). In more detail, the ratio (D) between the diameter of the aerosol-generating article at the mouth end and the diameter of the aerosol-generating article at the distal end _ME /D _DE ) And (preferably) at least about 1.005.

Preferably, the ratio (D) between the diameter of the aerosol-generating article at the mouth end and the diameter of the aerosol-generating article at the distal end _ME /D _DE ) And (preferably) at least about 1.01. More preferably, the ratio (D) between the diameter of the aerosol-generating article at the mouth end and the diameter of the aerosol-generating article at the distal end _ME /D _DE ) At least about 1.02. Even more preferably, the ratio (D) between the diameter of the aerosol-generating article at the mouth end and the diameter of the aerosol-generating article at the distal end _ME /D _DE ) Is at least about 1.05.

The ratio (D) between the diameter of the aerosol-generating article at the mouth end and the diameter of the aerosol-generating article at the distal end _ME /D _DE ) Preferably less than or equal to about 1.30. More preferably, the ratio (D) between the diameter of the aerosol-generating article at the mouth end and the diameter of the aerosol-generating article at the distal end _ME /D _DE ) Less than or equal to about 1.25. Even more preferably, the ratio (D) between the diameter of the aerosol-generating article at the mouth end and the diameter of the aerosol-generating article at the distal end _ME /D _DE ) Less than or equal to about 1.20. In a particularly preferred embodiment, the ratio (D) between the diameter of the aerosol-generating article at the mouth end and the diameter of the aerosol-generating article at the distal end _ME /D _DE ) Less than or equal to 1.15 or 1.10.

In some preferred embodiments, the ratio (D) between the diameter of the aerosol-generating article at the mouth end and the diameter of the aerosol-generating article at the distal end _ME /D _DE ) About 1.01 to 1.30, more preferably 1.02 to 1.30, even more preferably 1.05 to 1.30.

In other embodiments, the ratio (D) between the diameter of the aerosol-generating article at the mouth end and the diameter of the aerosol-generating article at the distal end _ME /D _DE ) About 1.01 to 1.25, more preferably 1.02 to 1.25, even more preferably 1.05 to 1.25. In a further embodiment, the ratio (D) between the diameter of the aerosol-generating article at the mouth end and the diameter of the aerosol-generating article at the distal end _ME /D _DE ) About 1.01 to 1.20, more preferably 1.02 to 1.20, even more preferably 1.05 to 1.20. In yet further embodiments, the ratio (D) between the diameter of the aerosol-generating article at the mouth end and the diameter of the aerosol-generating article at the distal end _ME /D _DE ) About 1.01 to 1.15, more preferably 1.02 to 1.15, even more preferably 1.05 to 1.15.

For example, the outer diameter of the article may be substantially constant over a distal portion of the article that extends at least about 5 millimeters or at least about 10 millimeters from the distal end of the aerosol-generating article. Alternatively, the outer diameter of the article may taper over a distal portion of the article that extends at least about 5 millimeters or at least about 10 millimeters from the distal end.

In certain preferred embodiments of the present invention, the elements of the aerosol-generating article as described above are arranged such that the centre of mass of the aerosol-generating article is at least about 60% along the length of the aerosol-generating article from the downstream end. More preferably, the elements of the aerosol-generating article are arranged such that the centre of mass of the aerosol-generating article is at least about 62% along the length of the aerosol-generating article from the downstream end, more preferably at least about 65% along the length of the aerosol-generating article from the downstream end.

Preferably, the centre of mass is no more than about 70% along the length of the aerosol-generating article from the downstream end.

Providing an element arrangement having a center of mass closer to the upstream end than the downstream end results in an aerosol-generating article having a weight imbalance with a heavier upstream end. Such weight imbalance may advantageously provide haptic feedback to consumers to enable them to distinguish between an upstream end and a downstream end so that the correct end may be inserted into the aerosol-generating device. This may be particularly beneficial in case the upstream element is provided such that the upstream and downstream ends of the aerosol-generating article are visually similar to each other.

In an embodiment of the aerosol-generating article according to the invention, in which both the aerosol-cooling element and the support element are present, these are preferably packaged together in a combined wrapper. The combination wrapper defines an aerosol-cooling element and a support element, but not another downstream (e.g. mouthpiece) element.

In these embodiments, the aerosol-cooling element and the support element are combined prior to being defined by the combination wrapper, after which they are further combined with the mouthpiece segment.

This is advantageous from a manufacturing point of view, as it enables shorter aerosol-generating articles to be assembled.

In general, it may be difficult to handle individual elements having a length less than their diameter. For example, for a 7 mm diameter element, a length of about 7 mm represents a threshold value, which is preferably not approached. However, a 10 mm aerosol-cooling element may be combined with a pair of support elements of 7 mm on each side (and potentially with other elements such as strips of aerosol-forming substrate) to provide a 24 mm hollow section which is then cut into two intermediate hollow sections of 12 mm.

In a particularly preferred embodiment, the other components of the aerosol-generating article are defined solely by their own wrapper. In other words, the upstream element, the strip of aerosol-forming substrate, the support element and the aerosol-cooling element are all individually packaged. The support element and the aerosol-cooling element combine to form an intermediate hollow section. This is achieved by packaging the support element and the aerosol-cooling element by means of a combined package. The upstream element, the strip of aerosol-forming substrate and the intermediate hollow section are then combined with the outer wrapper. They are then combined with the mouthpiece element with its own wrapper by means of tipping paper.

Preferably, at least one component of the aerosol-generating article is packaged in a hydrophobic wrapper.

The term "hydrophobic" means that the surface exhibits water-repellent properties. One useful method of determining this is to measure the water contact angle. The "water contact angle" is the angle through a liquid as conventionally measured when the liquid/vapor interface encounters a solid surface. It quantifies the wettability of a solid surface by a liquid via the young's equation. Hydrophobicity or water contact angle can be determined by using TAPPI T558 test method, and the results are presented as interface contact angles and reported in degrees, and can range from near zero degrees to near 180 degrees.

In a preferred embodiment, the hydrophobic wrapper is a wrapper comprising a paper layer having a water contact angle of about 30 degrees or greater, and preferably about 35 degrees or greater, or about 40 degrees or greater, or about 45 degrees or greater.

For example, the paper layer may comprise PVOH (polyvinyl alcohol) or silicon. PVOH may be applied as a surface coating to the paper layer, or the paper layer may include a surface treatment comprising PVOH or silicon.

In a particularly preferred embodiment, the aerosol-generating article according to the invention comprises, arranged in a linear order: an upstream element, a strip of aerosol-forming substrate located immediately downstream of the upstream element, a support element located immediately downstream of the strip of aerosol-forming substrate, an aerosol-cooling element located immediately downstream of the support element, a mouthpiece element located immediately downstream of the aerosol-cooling element, and an overwrap defining the upstream element, the support element, the aerosol-cooling element, and the mouthpiece element.

In more detail, the strip of aerosol-forming substrate may abut the upstream element. The support element may abut a strip of aerosol-forming substrate. The aerosol-cooling element may abut the support element. The mouthpiece element may abut the aerosol-cooling element.

The aerosol-generating article has a generally cylindrical shape and an outer diameter of about 7.25 millimeters. The circumference of the aerosol-generating article is preferably between 20 and 23 mm, more preferably between 21 and 22 mm.

The upstream element has a length of about 5 mm, the strip of aerosol-generating article has a length of about 12 mm, the support element has a length of about 8 mm, and the mouthpiece element has a length of about 12 mm. Thus, the overall length of the aerosol-generating article is about 45 millimeters.

The upstream element is in the form of a cellulose acetate mandrel packed in a rigid mandrel pack.

The aerosol-generating article comprises an elongate susceptor arranged substantially longitudinally within the strip of aerosol-forming substrate and in thermal contact with the aerosol-forming substrate. The susceptor is in the form of a strip or blade having a length substantially equal to the length of the strip of aerosol-forming substrate and a thickness of about 60 microns.

The support element is in the form of a hollow cellulose acetate tube and has an inner diameter of about 1.9 mm. Thus, the thickness of the peripheral wall of the support element is about 2.675 millimeters.

The aerosol-cooling element is in the form of a relatively thin hollow cellulose acetate tube and has an inner diameter of about 3.25 millimeters. Thus, the thickness of the peripheral wall of the aerosol-cooling element is about 2 millimeters.

The mouthpiece is in the form of a low density cellulose acetate filter segment.

The strip of aerosol-forming substrate comprises at least one of the types of aerosol-forming substrate described above, such as homogenized tobacco, gel formulation or homogenized plant material comprising particles of a plant other than tobacco.

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

Example a: an aerosol-generating article comprising:

a strip of aerosol-generating substrate;

a ventilation zone arranged downstream of the strip of aerosol-generating substrate;

wherein the ventilation zone comprises perforations, wherein the perforations are arranged in a peripheral wall of the ventilation zone, wherein each perforation has a central axis, wherein the aerosol-generating article has a central axis, wherein a minimum distance between the central axis of each perforation and the central axis of the aerosol-generating article is between 3% and 15% of an outer diameter of the aerosol-generating article, and wherein a thickness of the peripheral wall of the ventilation zone is between 0.1 and 2.5 millimeters.

Example B: an aerosol-generating article according to example a, wherein the minimum distance between the central axis of each perforation and the central axis of the aerosol-generating article is between 3% and 15% of the outer diameter of the aerosol-generating article, preferably between 4% and 13% of the outer diameter of the aerosol-generating article, more preferably between 5% and 10% of the outer diameter of the aerosol-generating article, most preferably 6% of the outer diameter of the aerosol-generating article.

Example C: an aerosol-generating article according to any of the preceding examples, wherein each central axis of each perforation is at an angle of between 3 ° and 20 °, preferably at an angle of between 4 ° and 15 °, more preferably at an angle of between 5 ° and 10 °, most preferably at an angle of 7 °, with respect to the radial direction of the aerosol-generating article.

Example D: an aerosol-generating article according to any of the preceding examples, wherein each perforation has a length measured along a central axis of the perforation, and wherein one or more perforations have a length of at least between 0.1 mm and 2.7 mm, preferably between 0.8 mm and 2.4 mm, more preferably between 1.2 mm and 2.0 mm, most preferably about 1.7 mm.

Example E: an aerosol-generating article according to any of the preceding examples, wherein the cross-sectional shape of the one or more perforations is constant along the central axis of the perforations.

Example F: an aerosol-generating article according to any of the preceding examples, wherein one or more of the perforations have a non-circular cross-section.

Example G: an aerosol-generating article according to any of the preceding examples, wherein one or more of the perforations are slit-shaped or have an oval cross-section.

Example H: an aerosol-generating article according to any of the preceding examples, wherein between 10 and 12 perforations are provided, preferably wherein the number of perforations is 11.

Example I: an aerosol-generating article according to any of the preceding examples, wherein the ventilation zone is arranged in a second hollow tubular section of the aerosol-cooling element, and wherein the second hollow tubular section has a thickness of 130mm ³ And 200mm ³ Preferably between 155mm ³ And 185mm ³ Between them, more preferably 170mm ³ Is provided.

Example J: an aerosol-generating article according to any of the preceding examples, wherein the perforations are arranged in the peripheral wall of the ventilation zone, preferably wherein the perforations have a non-constant pitch, wherein the coefficient of variation of the pitch is higher than 5%.

Example K: an aerosol-generating article according to the preceding example, wherein the ventilation zone is configured as a hollow tubular ventilation zone, and wherein the hollow tubular ventilation zone has an inner diameter of between 2.5 mm and 5.0 mm, preferably between 3.0 mm and 4.0 mm, more preferably between 3.1 mm and 3.5 mm, most preferably 3.3 mm.

Example L: an aerosol-generating article according to the preceding example, wherein the peripheral wall of the ventilation zone has a thickness of between 0.8 mm and 2.2 mm, more preferably between 1.2 mm and 1.8 mm, most preferably about 1.5 mm.

Example M: an aerosol-generating article according to any of the preceding examples, wherein the perforations are arranged in rows.

Example N: an aerosol-generating article according to any of the preceding examples, wherein the distance between the perforations of the ventilation zone and the downstream end of the strip of aerosol-generating substrate is between 1 mm and 6 mm, preferably between 2 mm and 5 mm, more preferably between 3 mm and 4 mm.

Example O: an aerosol-generating article according to any of the preceding examples, wherein the distance between the perforations of the ventilation zone and the downstream end of the aerosol-generating article is between 10 and 26 mm, preferably between 12 and 24 mm, more preferably between 14 and 22 mm, most preferably between 16 and 20 mm.

Example P: an aerosol-generating article according to any of the preceding examples, wherein the perforations are configured to allow ambient air to be drawn into the ventilation zone.

Example Q: an aerosol-generating article according to the preceding example, wherein the ratio of ambient air drawn into the ventilation zone through the perforations to air drawn into the ventilation zone through the strip of aerosol-forming substrate is between 5% and 75%, preferably between 20% and 65%, more preferably between 30% and 60%, more preferably between 40% and 55%, most preferably 50%.

Example V: an aerosol-generating article according to any of the preceding examples, wherein the aerosol-generating article further comprises a filter-tip segment downstream of the ventilation zone, wherein the suction resistance of the filter-tip segment is between 5 mm H2O and 80 mm H2O, preferably between 10 mm H2O and 65 mm H2O, more preferably between 15 mm H2O and 50 mm H2O, more preferably between 20 mm H2O and 40 mm H2O, most preferably 30 mm H2O.

Example W: an aerosol-generating system comprising an aerosol-generating device having a cavity for receiving an aerosol-generating article according to any of the preceding examples.

Example X: a method for manufacturing an aerosol-generating article, wherein the method comprises the steps of:

providing a strip of aerosol-generating substrate;

Drawings

The invention is further described below with reference to the accompanying drawings:

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

fig. 2 shows a cross-sectional view through a ventilation zone of an aerosol-generating article.

Detailed Description

The aerosol-generating article 10 shown in fig. 1 comprises a rod 12 of aerosol-forming substrate 12 and a downstream section 14 located at a position downstream of the rod 12 of aerosol-forming substrate. Furthermore, the aerosol-generating article 10 comprises an upstream section 16 at a location upstream of the strip 12 of aerosol-forming substrate. Thus, the aerosol-generating article 10 extends from an upstream or distal end 18 to a downstream or mouth end 20.

The aerosol-generating article has an overall length of about 45 millimeters.

The downstream section 14 includes a support element 22 located immediately downstream of the rod 12 of aerosol-forming substrate, the support element 22 being longitudinally aligned with the rod 12. In the embodiment of fig. 1, the upstream end of the support element 18 abuts the downstream end of the strip 12 of aerosol-forming substrate. In addition, the downstream section 14 includes an aerosol-cooling element 24 located immediately downstream of the support element 22, the aerosol-cooling element 24 being longitudinally aligned with the strip 12 and the support element 22. In the embodiment of fig. 1, the upstream end of the aerosol-cooling element 24 abuts the downstream end of the support element 22.

As will be apparent from the following description, the support element 22 and the aerosol-cooling element 24 together define the intermediate hollow section 50 of the aerosol-generating article 10. Overall, the middle is hollowThe section 50 does not substantially contribute to the overall RTD of the aerosol-generating article. The RTD of the intermediate hollow section 26 is substantially 0 mm H overall ₂ O。

The support element 22 comprises a first hollow tubular section 26. The first hollow tubular section 26 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The first hollow tubular section 26 defines an inner lumen 28 extending from an upstream end 30 of the first hollow tubular section up to a downstream end 32 of the first hollow tubular section 20. The lumen 28 is substantially empty and thus a substantially non-limiting flow of air is achieved along the lumen 28. The first hollow tubular section 26 and thus the support element 22 do not substantially contribute to the overall RTD of the aerosol-generating article 10. In more detail, the RTD of the first hollow tubular segment 26 (which is essentially the RTD of the support element 22) is essentially 0 millimeters H ₂ O。

The first hollow tubular section 26 has a length of about 8 millimeters, an outer diameter of about 7.25 millimeters, and an inner diameter (D) of about 1.9 millimeters _FTS ). Thus, the thickness of the peripheral wall of the first hollow tubular section 26 is about 2.67 millimeters.

The aerosol-cooling element 24 comprises a second hollow tubular section 34. The second hollow tubular section 34 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The second hollow tubular section 34 defines an inner lumen 36 extending from an upstream end 38 of the second hollow tubular section up to a downstream end 40 of the second hollow tubular section 34. The interior cavity 36 is substantially empty and thus a substantially non-limiting flow of air is achieved along the interior cavity 36. The second hollow tubular section 28, and thus the aerosol-cooling element 24, does not substantially contribute to the overall RTD of the aerosol-generating article 10. In more detail, the RTD of the second hollow tubular section 34 (which is essentially the RTD of the aerosol-cooling element 24) is essentially 0 millimeters H ₂ O。

The second hollow tubular section 34 has a length of about 8 millimeters, an outer diameter of about 7.25 millimeters, and an inner diameter (D) of about 3.25 millimeters _STS ). Thus, the thickness of the peripheral wall of the second hollow tubular section 34 is about 2 millimeters. Thus, the inner diameter (D _FTS ) With the inner diameter (D) of the second hollow tubular section 34 _STS ) The ratio between is about0.75。

The aerosol-generating article 10 comprises a ventilation zone 60 provided at a position along the second hollow tubular section 34. In more detail, the ventilation zone is provided at about 2 mm from the upstream end of the second hollow tubular section 34. The ventilation level of the aerosol-generating article 10 is about 25%.

In the embodiment of fig. 1, the downstream section 14 further includes a mouthpiece element 42 at a location downstream of the intermediate hollow section 50. In more detail, the mouthpiece element 42 is positioned immediately downstream of the aerosol-cooling element 24. As shown in the diagram of fig. 1, the upstream end of the mouthpiece element 42 abuts the downstream end 40 of the aerosol-cooling element 18.

The mouthpiece element 42 is provided in the form of a cylindrical filter segment of low density cellulose acetate.

The mouthpiece element 42 has a length of about 12 mm and an outer diameter of about 7.25 mm. The RTD of the mouthpiece element 42 is about 12 mm H ₂ O。

The rod 12 comprises an aerosol-forming substrate of one of the types described above.

The strips 12 of aerosol-forming substrate have an outer diameter of about 7.25 mm and a length of about 12 mm.

The aerosol-generating article 10 further comprises an elongate susceptor 44 within the strip 12 of aerosol-forming substrate. In more detail, the susceptor 44 is arranged substantially longitudinally within the aerosol-forming substrate so as to be substantially parallel to the longitudinal direction of the rod 12. As shown in the diagram of fig. 1, the susceptor 44 is positioned in a radially central position within the strip and extends effectively along the longitudinal axis of the strip 12.

The susceptor 44 extends from the upstream end of the strip 12 to the downstream end. In practice, the susceptor 44 has substantially the same length as the strip 12 of aerosol-forming substrate.

In the embodiment of fig. 1, the susceptor 44 is provided in a strip form and has a length of about 12 millimeters, a thickness of about 60 micrometers, and a width of about 4 millimeters. The upstream section 16 includes an upstream element 46 located immediately upstream of the rod 12 of aerosol-forming substrate, the upstream element 46 being longitudinally aligned with the rod 12. In the embodiment of fig. 1, the downstream end of the upstream element 46 abuts the upstream end of the rod 12 of aerosol-forming substrate. This advantageously prevents the susceptor 44 from being removed. In addition, this ensures that the consumer does not accidentally touch the heated susceptor 44 after use.

The upstream element 46 is provided in the form of a cylindrical cellulose acetate rod defined by a rigid wrapper. The upstream element 46 has a length of about 5 mm. The RTD of upstream element 46 is about 30 millimeters H ₂ O。

Fig. 2 shows a ventilation zone 60 of the aerosol-generating article, more particularly a cross-sectional view of the ventilation zone 60. A plurality of perforations 62 are provided in the ventilation zone 60. Perforations 62 are provided in hollow tubular section 34. 11 perforations 62 are provided. Perforations 62 penetrate hollow tubular section 34 such that ambient air may flow into hollow tubular section 34 through perforations 62. Ambient air may flow into the lumen 36 of the hollow tubular section 34 through the perforations 62.

As can be seen in fig. 2, the perforations are inclined. Illustratively, the central axis CA of the bore _PER Shown in fig. 2. Central axis CA of the perforation _PER Extending the perimeter cross-sectional center of the perforation and the inner cross-sectional center of the perforation. The perimeter cross-sectional center of the perforations may be the cross-sectional center of the perforations at the outermost open areas 64 of the perforations shown in fig. 2. The inner cross-sectional center of the perforation may be the cross-sectional center of the perforation at the innermost open area 66 of the perforation shown in fig. 2. Figure 2 also shows the central axis CA of the aerosol-generating article _ART . Central axis CA of aerosol-generating article _ART Is the central longitudinal axis of the aerosol-generating article. As can be seen in fig. 2, the central axis CA of the perforation _PER Arranged to be in contact with the central axis CA of the aerosol-generating article _ART Spaced apart by a distance d. This is true for all of the perforations 62. All perforations 62 are inclined such that the central axis of the perforations 62 is in line with the central axis CA of the aerosol-generating article _ART Spaced apart.

Features described with respect to one embodiment may be equally applicable to other embodiments of the invention.

Claims

1. An aerosol-generating article comprising:

a strip of aerosol-generating substrate;

Wherein the ventilation zone comprises perforations, wherein the perforations are arranged in a peripheral wall of the ventilation zone, wherein each perforation has a central axis, wherein the aerosol-generating article has a central axis, wherein a minimum distance between the central axis of each perforation and the central axis of the aerosol-generating article is between 3% and 15% of an outer diameter of the aerosol-generating article, wherein a thickness of the peripheral wall of the ventilation zone is between 0.1 and 2.5 millimeters, wherein the aerosol-generating article has a ventilation level of at least 20%.

2. An aerosol-generating article according to claim 1, wherein the minimum distance between the central axis of each perforation and the central axis of the aerosol-generating article is between 4% and 13% of the outer diameter of the aerosol-generating article, more preferably between 5% and 10% of the outer diameter of the aerosol-generating article, most preferably 6% of the outer diameter of the aerosol-generating article.

3. An aerosol-generating article according to any one of the preceding claims, wherein each central axis of each perforation is at an angle of between 3 ° and 20 °, preferably at an angle of between 4 ° and 15 °, more preferably at an angle of between 5 ° and 10 °, most preferably at an angle of 7 °, with respect to the radial direction of the aerosol-generating article.

4. An aerosol-generating article according to any one of the preceding claims, wherein each perforation has a length measured along a central axis of the perforation, and wherein one or more perforations have a length of at least between 0.1 and 2.7 mm, preferably between 0.8 and 2.4 mm, more preferably between 1.2 and 2.0 mm, most preferably about 1.7 mm.

5. An aerosol-generating article according to any one of the preceding claims, wherein the cross-sectional shape of one or more perforations is constant along the central axis of the perforations.

6. An aerosol-generating article according to any one of the preceding claims, wherein one or more of the perforations have a non-circular cross-section.

7. An aerosol-generating article according to any one of the preceding claims, wherein one or more of the perforations are slit-shaped or have an oval cross-section.

8. An aerosol-generating article according to any one of the preceding claims, wherein between 10 and 12 perforations are provided, preferably wherein the number of perforations is 11.

9. An aerosol-generating article according to any one of the preceding claims, wherein the ventilation zone is arranged in a hollow tubular section of an aerosol-cooling element, and wherein the hollow tubular section has a thickness of 130mm ³ And 200mm ³ Preferably between 155mm ³ And 185mm ³ Between them, more preferably 170mm ³ Is provided.

10. An aerosol-generating article according to any one of the preceding claims, wherein the distance between the perforations of the ventilation zone and the downstream end of the strip of aerosol-generating substrate is between 1 and 6 mm, preferably between 2 and 5mm, more preferably between 3 and 4 mm.

11. An aerosol-generating article according to any one of the preceding claims, wherein the distance between the perforations of the ventilation zone and the downstream end of the aerosol-generating article is between 10 and 26 mm, preferably between 12 and 24 mm, more preferably between 14 and 22 mm, most preferably between 16 and 20 mm.

12. An aerosol-generating article according to the preceding claim, wherein the ratio of ambient air drawn into the ventilation zone through the perforations to air drawn into the ventilation zone through the strip of aerosol-forming substrate is between 5% and 75%, preferably between 20% and 65%, more preferably between 30% and 60%, more preferably between 40% and 55%, most preferably 50%.

13. An aerosol-generating article according to any one of the preceding claims, wherein the aerosol-generating article further comprises a filter-filter segment downstream of the ventilation zone, wherein the filter-filter segment has a suction resistance of 5 millimeters H ₂ O and 80 mm H ₂ O, preferably between 10 mm H ₂ O and 65 mm H ₂ O, more preferably between 15 mm H ₂ O and 50 mm H ₂ O, more preferably at 20 mm H ₂ O and 40 mm H ₂ Between O, most preferably 30 mm H ₂ O。

14. An aerosol-generating article according to any one of the preceding claims, wherein the aerosol-generating article further comprises a matrix wrapper at least partially defining the strip of aerosol-forming matrix, and wherein the matrix wrapper has a thickness of 50 microns or more, preferably 65 microns or more, more preferably 80 microns or more.

15. An aerosol-generating system comprising an aerosol-generating device having a cavity for receiving an aerosol-generating article according to any of the preceding claims.

16. A method for manufacturing an aerosol-generating article, wherein the method comprises the steps of:

-providing a strip of aerosol-generating substrate;

-providing a ventilation zone downstream of the strip of aerosol-generating substrate; and

-creating perforations in the peripheral wall of the ventilation zone, wherein each perforation has a central axis, wherein the aerosol-generating article has a central axis, and wherein the minimum distance between the central axis of each perforation and the central axis of the aerosol-generating article is between 3% and 15% of the outer diameter of the aerosol-generating article, wherein the aerosol-generating article has a ventilation level of at least 20%.