RU2850257C2 - Aerosol-generating device with non-circular perforations in the ventilation area - Google Patents

Abstract

FIELD: an aerosol-generating device.

SUBSTANCE: the present invention relates to an aerosol-generating product (10) comprising an aerosol-generating substrate rod (12). The aerosol-generating product further comprises a ventilation zone (60) located downstream of the aerosol-generating substrate rod. The ventilation zone contains perforations. One or more of the perforations have a non-circular cross-section having an ovality, wherein the ovality is a ratio of the major diameter of the perforation to the minor diameter of the perforation of at least 1.5. The thickness of the peripheral wall of the ventilation zone is between 0.1 millimetres and 2.5 millimetres. One or more of the perforations have a width between 0.05 millimetres and 0.2 millimetres and a length between 0.25 millimetres and 1.0 millimetres. The present invention further relates to an aerosol generating system comprising an aerosol generating device having a cavity for accommodating an aerosol generating article.

EFFECT: method for manufacturing an aerosol generating device.

13 cl, 3 dwg

Description

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

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

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 the aerosol is generated by transferring heat from one or more electrical heating elements of the aerosol-generating device to an aerosol-generating substrate of the heated aerosol-generating article. For example, electrically heated aerosol-generating devices have been proposed that comprise an internal heating plate adapted for insertion into the aerosol-generating substrate. Alternatively, inductively heated aerosol-generating articles have been proposed, comprising an aerosol-generating substrate and a susceptor located within the aerosol-generating substrate. Alternatively, the current collector device may be located in the aerosol generating device, for example, at least partially surrounding a cavity for accommodating the aerosol generating article.

Aerosol-generating products in which the tobacco-containing substrate is heated rather than combusted pose a number of challenges not previously encountered with conventional smoking products. First, tobacco-containing substrates are typically heated to significantly lower temperatures than those reached by the combustion front in a conventional cigarette. This can impact the release of nicotine from 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 more quickly before reaching the consumer. However, technical solutions widely used to cool the mainstream smoke in conventional smoking products, such as the provision of a high-efficiency filtration segment at the mouth end of the cigarette, can have undesirable effects on an aerosol-generating product in which the tobacco-containing substrate is heated rather than combusted, as they can reduce nicotine delivery. Secondly, there is a fundamental need for aerosol generating products that are easy to use and have improved practicality.

It would be desirable to provide an aerosol-generating article that can be manufactured efficiently and at high speed, preferably with a satisfactory RTD and low RTD variability from one article to another. It would be desirable to provide an aerosol-generating article that provides effective cooling. It would be desirable to provide an aerosol-generating article that provides effective cooling of the aerosol. It would be desirable to provide an aerosol-generating article that provides effective cooling of the evaporating aerosol-forming substrate. It would be desirable to provide an aerosol-generating article that provides effective mixing of ambient air with the evaporating aerosol-forming substrate.

It would be desirable to provide a new and improved aerosol generating article adapted to achieve at least one of the desired results described above.

According to an embodiment of the present invention, an aerosol-generating article is provided, which may comprise a rod of aerosol-generating substrate. The aerosol-generating article may further comprise a ventilation zone located downstream of the rod of aerosol-generating substrate. The ventilation zone may comprise perforations. One or more of the perforations may have a non-circular cross-section having ovality, wherein the ovality is a ratio of the major diameter of the perforation to the minor diameter of the perforation of at least 1.5. The thickness of the peripheral wall of the ventilation zone may range from 0.1 millimeters to 2.5 millimeters.

According to an embodiment of the present invention, an aerosol-generating article is provided, comprising a rod of aerosol-generating substrate. The aerosol-generating article further comprises a ventilation zone located downstream of the rod of aerosol-generating substrate. The ventilation zone comprises perforations. One or more of the perforations have a non-circular cross-section having an ovality, wherein the ovality is a ratio of the major diameter of the perforation to the minor diameter of the perforation of at least 1.5. The thickness of the peripheral wall of the ventilation zone ranges from 0.1 millimeters to 2.5 millimeters.

The presence of a non-circular cross-section can improve the mixing of ambient air drawn into the ventilation zone through the perforations with air drawn into the ventilation zone through the aerosol-forming substrate rod. The shape of the perforations can influence the flow of ambient air drawn into the ventilation zone. Non-circular perforations can create a more turbulent airflow, thereby improving the mixing of ambient air with air drawn through the aerosol-forming substrate rod.

The cross-sectional shape of the perforations may be visible in a plane parallel to the central axis of the ventilation zone. The central axis of the ventilation zone is preferably identical to the central axis of the entire aerosol-generating article. The cross-sectional shape of the perforations may be visible in the outermost or peripheral open area of the perforation.

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

One or more of the perforations may be in the form of a slot.

For one or more of the perforations, the length of the perforations may be greater than the width of the perforations. Preferably, the length is 1.5 times greater than the width, more preferably 2.5 times greater than the width, more preferably 4 times greater than the width, and most preferably 5 times greater than the width for one or more of the perforations.

For one or more of the perforations, the longitudinal axis of the perforation may be parallel to the longitudinal axis of the aerosol generating article.

One or more perforations may have a width of from 0.05 millimeters to 0.2 millimeters, preferably from 0.1 millimeters to 0.15 millimeters, most preferably from 0.11 millimeters to 0.13 millimeters.

One or more perforations may have a length of from 0.25 millimeters to 1.0 millimeters, preferably from 0.4 millimeters to 0.8 millimeters, most preferably from 0.5 millimeters to 0.6 millimeters.

The ovality of the perforation holes may be at least 2, preferably at least 3, more preferably at least 4, most preferably at least 5.

The ventilation zone may have 5 to 15 perforations. Preferably, 7 to 14 perforations are provided in the ventilation zone. Preferably, 9 to 13 perforations are provided in the ventilation zone. Preferably, 10 to 12 perforations are provided in the ventilation zone. The preferred number of perforations is 11.

A ventilation zone with perforations can allow ambient air to be drawn into the ventilation zone. This ambient air can mix with air drawn through the aerosol-forming substrate rod. The aerosol-forming substrate rod can be heated by the aerosol-generating device, causing the aerosol-forming substrate to evaporate. The evaporated aerosol-forming substrate can be drawn into the air passing through the aerosol-forming substrate rod. This air stream mixes with ambient air downstream of the aerosol-forming substrate rod in the ventilation zone. The mixing of ambient air with air drawn through the aerosol-forming substrate rod provides cooling, resulting in aerosol formation. The presence of 10 to 12 perforations may improve the mixing of ambient air drawn through the perforations into the ventilation zone with the air drawn into the ventilation zone through the aerosol-forming substrate rod. This improved mixing may lead to improved aerosol generation. Without being bound by any theory, it was found that a number of perforations between 10 and 12 provides the best mixture of ambient air and air containing the evaporable aerosol-forming substrate. This may be because a relatively small number of perforations requires relatively large perforations to ensure a sufficient amount of ambient air drawn into the ventilation zone. A relatively large perforation may lead to relatively strong turbulence between the two air streams, thus improving mixing of the two air streams.

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

Each central axis of each perforation may be positioned at an angle relative to the radial direction of the aerosol generating article of from 3° to 20°, preferably at an angle of from 4° to 15°, more preferably at an angle of from 5° to 10°, most preferably at an angle of 7°.

This perforation angle can result in a turbulent flow of ambient air drawn into the ventilation zone through the perforations. This can improve mixing of ambient air with the air drawn through the aerosol-forming substrate rod.

The internal diameter of the hollow tubular ventilation zone may be from 2.5 millimeters to 7.5 millimeters, preferably from 3.5 millimeters to 6.5 millimeters, more preferably from 4.0 millimeters to 6.0 millimeters, more preferably from 4.5 millimeters to 5.5 millimeters, most preferably 5.0 millimeters.

The ventilation zone may be located in the second hollow tubular segment of the aerosol cooling element. The second hollow tubular segment may have an internal volume of 130 mm ³ to 200 mm ³ , preferably 155 mm ³ to 185 mm ³ , more preferably 170 mm ³ .

Perforations may be located in the peripheral wall of the ventilation zone. The perforations may be located asymmetrically in the peripheral wall. The arrangement may be asymmetrical in such a way that it is not point-symmetrical with respect to any point on the central longitudinal axis of the aerosol-generating article. Additionally or alternatively, the arrangement may be asymmetrical in such a way that it lacks linear symmetry.

Perforations may be arranged in the peripheral wall of the ventilation zone with a variable pitch. The pitch of the perforations is the distance between the perforations. A variable pitch arrangement of perforations may have a pitch coefficient of variation greater than 5%, preferably greater than 10%, and more preferably greater than 15%. The variation coefficient is the ratio of the standard deviation to the mean. A variable pitch arrangement of perforations may have a pitch coefficient of variation less than 40%, preferably less than 35%, and more preferably less than 30%.

In other words, a first pair of adjacent perforations may have a first distance between them, 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 between them, measured along the arc length of the peripheral wall; and a third pair of adjacent perforations, different from the first pair and the second pair, may have a third distance between them, measured along the arc length of the peripheral wall. All of the first distance, second distance, and third distance may be different.

In one embodiment, more than half of the perforations may be located in one half of the peripheral wall of the ventilation zone, and less than half of the perforations may be located 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 located in one half of the peripheral wall of the ventilation zone, and less than one-third of the perforations may be located in the other half of the peripheral wall of the ventilation zone.

By using an asymmetrical perforation arrangement, it is possible to achieve the same quality of mixing of ambient air with air drawn through the aerosol-forming substrate rod. However, an asymmetrical perforation arrangement may be easier to fabricate or may allow for higher fabrication speeds. Furthermore, it is difficult to increase fabrication speed while maintaining a high-quality symmetrical perforation arrangement. It was found that using asymmetrical perforations, as described in this paper, does not reduce the quality of air mixing or aerosol generation.

Perforations may penetrate the peripheral wall.

A peripheral wall may at least partially surround the ventilation zone. The peripheral wall may completely surround the ventilation zone. The hollow tubular shape of the ventilation zone may be maintained by the peripheral wall of the ventilation zone. The peripheral wall may be adjacent to the environment surrounding the aerosol-generating article. The peripheral wall may be adjacent to the hollow interior of the ventilation zone.

The thickness of the peripheral wall of the ventilation zone may be from 0.8 millimeters to 2.2 millimeters, more preferably from 1.2 millimeters to 1.8 millimeters, most preferably approximately 1.5 millimeters.

The peripheral wall can be configured to provide a dimensionally stable ventilation zone. Since the perforations are located in the peripheral wall and since the perforations are inclined, the length of the perforations can range from 0.1 millimeters to 2.7 millimeters, preferably from 0.8 millimeters to 2.4 millimeters, more preferably from 1.2 millimeters to 2.0 millimeters, and most preferably approximately 1.7 millimeters.

The length of the perforation can affect airflow through the perforation. Airflow can be directed by the shape of the perforation. The angle of the perforation, as described in this document, can result in turbulent airflow as air exits the perforation.

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

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

Perforations can be arranged in a row. Perforations can be arranged like pearls on a string. A row of perforations can be arranged in a ring. A row of perforations can be arranged in a ring, the center of which is the central axis of the ventilation zone.

The distance between the perforations of the ventilation zone and the downstream end of the aerosol generating substrate rod may be from 1 millimeter to 6 millimeters, preferably from 2 millimeters to 5 millimeters, more preferably from 3 millimeters to 4 millimeters.

The placement of perforations in this area of the ventilation zone can improve aerosol generation. Aerosol generation can be improved by positioning the perforations so as to ensure optimized mixing between the ambient air drawn into the ventilation zone through the perforations and the air drawn into the perforations through the aerosol-forming substrate core.

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

The placement of perforations in this area of the ventilation zone can improve aerosol generation. Aerosol generation can be enhanced by optimizing the downstream distance of the perforations to allow for cooling of the mixture of ambient air and the air carrying the vaporized aerosol-forming substrate, thereby allowing for cooling of the mixture and subsequent aerosol formation.

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

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

This ratio can improve aerosol formation by achieving thorough mixing of ambient air and air drawn through the aerosol-forming substrate rod. This ratio can improve aerosol formation by achieving optimized cooling of air drawn through the aerosol-forming substrate rod due to mixing of this air with ambient air.

The aerosol-generating article may further comprise a filter rod located downstream of the ventilation zone. The resistance to draw (RTD) of the filter rod may range from 5 millimeters of water to 80 millimeters of water, preferably from 10 millimeters of water to 65 millimeters of water, more preferably from 15 millimeters of water to 50 millimeters of water, more preferably from 20 millimeters of water to 40 millimeters of water, and most preferably 30 millimeters of water. Typically, RTD can be measured using one of ISO 6565:2002 and CORESTA Recommended Method No. 41.

The overall draw resistance of an aerosol-generating product can essentially be determined by the draw resistance of the filter rod. The draw resistance of additional components of the aerosol-generating product, particularly the ventilation zone, may be negligible compared to the draw resistance of the filter rod.

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

providing an aerosol-generating substrate rod;

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

creating non-circular perforation holes in the peripheral wall of the ventilation zone, having ovality, wherein the ovality is a ratio of the large diameter of the perforation hole to the small diameter of the perforation hole, which is at least 1.5, and wherein the thickness of the peripheral wall of the ventilation zone is from 0.1 millimeter to 2.5 millimeters.

The present invention further relates to a method for manufacturing an aerosol generating article, the method comprising the steps of:

providing an aerosol-generating substrate rod;

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

creating non-circular perforation holes in the peripheral wall of the ventilation zone, having ovality, wherein the ovality is a ratio of the large diameter of the perforation hole to the small diameter of the perforation hole, which is at least 1.5, and wherein the thickness of the peripheral wall of the ventilation zone is from 0.1 millimeter to 2.5 millimeters.

The term "aerosol-generating article" is used in this document to refer to an article in which an aerosol-generating substrate is heated to produce and deliver an inhalable aerosol to the user. For the purposes of this document, the term "aerosol-generating substrate" refers to a substrate capable of releasing volatile compounds when heated to generate an aerosol.

As used herein, the term "aerosol generating device" refers to a device that includes a heating element that interacts with an aerosol generating substrate of an aerosol generating article to generate an aerosol.

In the context of this document, in relation to the present invention, the term "rod" is used to describe a substantially cylindrical element with a substantially circular, oval or elliptical cross-section.

For the purposes of this document, the term "longitudinal" refers to the 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. For the purposes of this document, the terms "upstream" and "downstream" describe the relative positions of elements or portions of elements of the aerosol-generating article relative to the direction in which the aerosol is transported through the aerosol-generating article during use.

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

The term "length" refers to the longitudinal dimension of an aerosol-generating component. For example, it can be used to describe the longitudinal dimension of a rod or elongated tubular segments.

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

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

As used herein, the term "homogenized plant material" encompasses any plant material formed by agglomerating plant particles. For example, sheets or webs of homogenized tobacco material for aerosol-forming substrates according to the present invention may be formed by agglomerating tobacco material particles obtained by grinding, crushing, or milling the plant material and, optionally, one or more of the lamellae of tobacco leaf and the veins of tobacco leaf. The homogenized plant material may be produced by casting, extrusion, papermaking, or any other suitable methods 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, the term "sheet" in relation to the present invention describes a layered element having a width and length that are substantially greater than its thickness.

The homogenized plant material may be in the form of multiple beads or granules.

Homogenized plant material may be in the form of multiple strands, strips, or pieces. For the purposes of this document, the term "strand" describes an elongated element of material whose length significantly exceeds its width and thickness. The term "strand" should be understood to encompass strips, pieces, and any other homogenized plant material of similar shape. Strands of homogenized plant material may be formed from a sheet of homogenized plant material, for example, by cutting or dividing it into pieces, or by other methods, such as extrusion.

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

The aerosol-forming substrate may further comprise one or more aerosol formers. Upon vaporization, the aerosol former may carry other vaporized compounds released from the aerosol-forming substrate upon heating, such as nicotine and flavorings, in the aerosol. Aerosol formers suitable for inclusion in the homogenized plant material are known in the art and include, but are not limited to: polyhydric alcohols such as triethylene glycol, propylene glycol, 1,3-butanediol, and glycerol; esters of polyhydric alcohols such as glycerol mono-, di-, or triacetate; and aliphatic esters of mono-, di-, or polycarboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate.

The aerosol-forming substrate may have an aerosol-forming substance content of from about 5 percent to about 30 percent by weight on a dry weight basis, such as from about 10 percent to about 25 percent by weight on a dry weight basis, or from about 15 percent to about 20 percent by weight on a dry weight basis.

For example, if the substrate is intended for use in an aerosol-generating article for an electric aerosol-generating system having a heating element, it may preferably comprise an aerosol-forming agent content of from about 5 percent to about 30 percent by weight, based on the dry weight. If the substrate is intended for use in an aerosol-generating article for an electric aerosol-generating system having a heating element, the aerosol-forming agent is preferably glycerol.

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

Preferably, the gel composition contains nicotine.

An aerosol-generating article may comprise a substrate wrapper that at least partially surrounds the aerosol-generating substrate. The substrate wrapper may comprise one or more layers of equal length along the longitudinal direction of the aerosol-generating article. The substrate wrapper may have a thickness of 30 to 45 micrometers. However, preferably, the substrate wrapper may have a thickness of 50 micrometers or more.

The substrate wrapper may have a thickness of 60 micrometers or more, preferably 65 micrometers or more, more preferably 75 micrometers or more, more preferably 80 micrometers or more, more preferably 90 micrometers or more, more preferably 100 micrometers or more, more preferably 110 micrometers or more, more preferably 120 micrometers or more, more preferably 130 micrometers or more, more preferably 140 micrometers or more, more preferably 145 micrometers or more, more preferably 150 micrometers or more. The substrate wrapper may have a thickness of approximately 148 micrometers. The substrate wrapper may have a thickness of 143 micrometers to 153 micrometers. The substrate wrapper may have a thickness of 140 micrometers to 160 micrometers.

The orientation of the perforation opening according to the present invention may be preferable when the tobacco rod is thin (i.e., when the rod of the aerosol-generating substrate has a relatively small radial thickness) compared to the outer diameter of the aerosol-generating article. This is particularly the case when the substrate wrapper is thick, as described herein (i.e., when the substrate wrapper has a thickness of 50 micrometers or more). This may be due to the fact that when the air flow is linear and the aerosol-generating substrate does not occupy the entire diameter of the rod, different mixing with the air coming from the vent opening may be required.

Substrate wrap may have a density of 800 kilograms per cubic meter or less.

Preferably, in the aerosol-generating article according to the present invention, the current collector is located within the rod of the aerosol-forming substrate and is in thermal contact with the aerosol-forming substrate. Preferably, the current collector is elongated.

In the context of this document, the term "susceptor" refers to a material capable of converting electromagnetic energy into heat. When placed within a fluctuating electromagnetic field, eddy currents induced in the susceptor cause the susceptor to heat up. Because the elongated susceptor is placed in thermal contact with the aerosol-forming substrate, the aerosol-forming substrate is heated by the susceptor.

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

The current collector is preferably located substantially longitudinally within the rod. This means that the length of the elongated current collector is approximately parallel to the rod's longitudinal direction, for example, within plus or minus 10 degrees parallel to the rod's longitudinal direction. In preferred embodiments, the elongated current collector may be located in a radially central position within the rod and extend along the rod's longitudinal axis.

Preferably, the susceptor extends the entire distance to the downstream end of the aerosol-generating article's rod. In some embodiments, the susceptor may extend the entire distance to the upstream end of the aerosol-generating article's rod. In particularly preferred embodiments, the susceptor has substantially the same length as the aerosol-generating substrate's rod and extends from the upstream end of the rod to the downstream end of the rod.

The current collector is preferably made in the form of a pin, rod, strip or plate.

The current collector preferably has a length of from about 5 millimeters to about 15 millimeters, such as from about 6 millimeters to about 12 millimeters, or from about 8 millimeters to about 10 millimeters.

The ratio between the length of the current collector and the total length of the substrate of the aerosol generating article may be from about 0.2 to about 0.35.

The current collector can be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol-forming substrate. Preferred current collectors comprise metal or carbon.

A preferred current collector may comprise or be composed of a ferromagnetic material, such as a ferromagnetic alloy, ferritic iron, ferromagnetic steel, or stainless steel. A suitable current collector may be made of or comprise aluminum. Preferred current collectors may be formed from 400-series stainless steels, such as Type 410, Type 420, or Type 430 stainless steel. Different materials will dissipate different amounts of energy when placed within electromagnetic fields of similar frequency and field strength.

Thus, all current collector parameters, such as material type, length, width, and thickness, can be adjusted to achieve the desired power dissipation within a known electromagnetic field. Preferred current collectors can be heated to temperatures exceeding 250 degrees Celsius.

Suitable current collectors may comprise a non-metallic core with a metallic layer located on the non-metallic core, for example, with metallic traces formed on the surface of a ceramic core. The current collector may have a protective outer layer, such as a protective ceramic layer or a protective glass layer, enclosing the current collector. The current collector may comprise a protective coating formed of glass, ceramic, or an inert metal, formed over the core of the current collector material.

The current collector is located in thermal contact with the aerosol-forming substrate. Thus, when the current collector is heated, the aerosol-forming substrate is heated, and an aerosol is formed. Preferably, the current collector is located 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 located at a location downstream of the aerosol-generating substrate rod. The downstream section may comprise an intermediate hollow section containing an aerosol-cooling element positioned in alignment with and downstream of the aerosol-generating substrate rod.

The downstream section may further comprise one or more downstream elements on top of the aerosol cooling element. By way of example, the intermediate hollow section may further comprise a support element located immediately downstream of the aerosol-forming substrate rod, and the aerosol cooling element may be positioned between the support element and the downstream end (or mouthpiece end) of the aerosol-generating article. In more detail, the aerosol cooling element may be located immediately downstream of the support element. In some preferred embodiments, the aerosol cooling element may be adjacent to the support element. As will be described below, the downstream section may further comprise 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 segment that defines a cavity extending the entire distance from an upstream end of the aerosol cooling element to a downstream end of the aerosol cooling element, and a ventilation zone may be provided at a location along the hollow tubular segment.

In the context of this document, the term "hollow tubular segment" is used to describe a generally elongated element defining a lumen or passage for air flow 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 passage establishing continuous 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, the hollow tubular segment provides an unrestricted flow path. This means that the hollow tubular segment provides a negligible resistance to draw (RTD). Therefore, the flow path must be free of any components that could restrict longitudinal airflow. Preferably, the flow path is substantially empty.

When used to describe an aerosol cooling element, the term "elongated" 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 its width dimension or its diameter dimension.

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

Without being limited by theory, it is hypothesized that, since the aerosol stream temperature rapidly decreases upon introduction of ventilation air as the aerosol moves toward the mouthpiece segment, introducing ventilation air into the aerosol stream at a location relatively close to the upstream end of the aerosol cooling element (i.e., sufficiently close to the susceptor extending within the aerosol-forming substrate rod, which serves as a heat source during use) results in rapid cooling of the aerosol stream, which has a beneficial effect on the condensation and nucleation of aerosol particles. Accordingly, the overall ratio of particulate aerosol to gas phase aerosol can be improved compared to existing non-ventilated aerosol-generating products.

The aerosol cooling element is positioned substantially in alignment with the rod. This means that the lengthwise dimension of the aerosol cooling element is approximately parallel to the longitudinal direction of the rod and the article, for example, within plus or minus 10 degrees parallel to the longitudinal direction of the rod. In preferred embodiments, the aerosol cooling element extends along the longitudinal axis of the rod. The longitudinal axis of the rod is preferably identical to the longitudinal axis of the aerosol-generating article. The longitudinal axis of the aerosol-generating article is preferably identical to the central axis of the aerosol-generating article.

The aerosol cooling element preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol-forming substrate rod and the outer diameter of the aerosol-generating article.

The aerosol cooling element may have an outer diameter of 5 millimeters to 12 millimeters, such as 5 millimeters to 10 millimeters, or 6 millimeters to 8 millimeters. In a preferred embodiment, the aerosol cooling element has an outer diameter of 7.2 millimeters, plus or minus 10 percent.

Preferably, the hollow tubular segment of the aerosol cooling element has an internal diameter of at least approximately 2 millimeters. More preferably, the hollow tubular segment of the aerosol cooling element has an internal diameter of at least approximately 3.5 millimeters. Even more preferably, the hollow tubular segment of the aerosol cooling element has an internal diameter of at least approximately 5 millimeters.

The peripheral wall of the aerosol cooling element may have a thickness of less than approximately 2.5 millimeters, preferably less than 22 millimeters. In particularly preferred embodiments, the peripheral wall of the aerosol cooling element has a thickness of between 1.2 millimeters and 1.8 millimeters.

In one embodiment, the peripheral wall of the aerosol cooling element has a thickness of approximately 1.5 millimeters.

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

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

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

Consequently, the aerosol cooling element can have a relatively short length compared to aerosol cooling elements of prior art aerosol-generating articles. Reducing the length of the aerosol cooling element is possible due to the optimized efficiency of the hollow tubular segment forming the aerosol cooling element in cooling and nucleating the aerosol. Reducing the length of the aerosol cooling element advantageously reduces the risk of deformation of the aerosol-generating article due to compression during use, as the aerosol cooling element typically has lower deformation resistance than the mouthpiece. Furthermore, reducing the length of the aerosol cooling element can result in lower manufacturing costs for the manufacturer, as the cost of a hollow tubular segment is typically higher per unit length than the cost of other elements, such as the mouthpiece.

The ratio between the length of the aerosol cooling element and the length of the aerosol forming substrate rod 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 aerosol-forming substrate rod is at least about 0.3, more preferably at least about 0.4, even more preferably at least about 0.5. In preferred embodiments, the ratio between the length of the aerosol cooling element and the length of the aerosol-forming substrate rod 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 rod of the 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 rod of the 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 rod of the 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 aerosol forming substrate rod may be approximately 0.66.

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

Preferably, the ratio between the length of the aerosol cooling element and the total length of the substrate of the aerosol generating article 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 total length of the substrate of the aerosol generating article 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 total length of the substrate of the aerosol generating article 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 total length of the substrate of the aerosol generating article 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 total length of the substrate of the aerosol generating article 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 total length of the substrate of the aerosol generating article is approximately 0.18.

Preferably, the length of the mouthpiece element is at least 1 millimeter longer than the length of the aerosol cooling element, more preferably at least 2 millimeters longer than the length of the aerosol cooling element, more preferably at least 3 millimeters longer than the length of the aerosol cooling element. Reducing the length of the aerosol cooling element, as described above, can advantageously allow for an increase in the length of other elements of the aerosol-generating article, such as the mouthpiece element. The potential technical advantages of providing a relatively long mouthpiece element are described above.

Preferably, in the aerosol-generating articles according to the present invention, the aerosol-cooling element has an average radial hardness of at least about 80 percent, more preferably at least about 85 percent, and even more preferably at least about 90 percent. Consequently, the aerosol-cooling element is capable of providing the desired level of hardness to the aerosol-generating article.

If desired, the radial hardness of the aerosol cooling element of the aerosol-generating articles according to the present invention can be further increased by surrounding the aerosol cooling element with a rigid filament, for example, a filament having a basis weight of at least about 80 grams per square meter (g/ ^m2 ), or at least about 100 g/ ^m2 , or at least about 110 g/ ^m2 .

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; corrugated paper, such as corrugated heat-resistant paper or corrugated parchment paper; 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 comprises a plurality of perforations through the peripheral wall of the aerosol cooling element. Preferably, the ventilation zone comprises at least one annular row of perforations. In some embodiments, the ventilation zone may comprise two annular rows of perforations. For example, the perforations may be formed on a production line during the manufacturing process of an aerosol-generating article. Preferably, each annular row of perforations comprises from 8 to 30 perforations. However, it has been found that a specific number of from 5 to 15 perforations, from 7 to 14 perforations, from 9 to 13 perforations, from 10 to 12 perforations, in particular a number of 11 perforations, leads to improved aerosol generation.

If the aerosol-generating article comprises a uniting rod for attaching the aerosol-cooling element to one or more other components of the aerosol-generating article, the ventilation zone preferably comprises at least one corresponding annular row of perforations provided through a portion of the uniting wick. They can also be formed on a production line during the manufacturing process of the smoking article. Preferably, the annular row or rows of perforations provided through a portion of the uniting wick are substantially aligned with the row or 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 segment of the aerosol-cooling element is at least approximately 1 millimeter. Preferably, the distance between the ventilation zone and the upstream end of the hollow tubular segment of the aerosol-cooling element is at least approximately 2 millimeters. More preferably, the distance between the ventilation zone and the upstream end of the hollow tubular segment of the aerosol cooling element is at least approximately 3 millimeters.

In some embodiments, the distance between the ventilation zone and the upstream end of the hollow tubular segment of the aerosol cooling element is approximately 6 millimeters or less. Preferably, the distance between the ventilation zone and the upstream end of the hollow tubular segment of the aerosol cooling element is approximately 5 millimeters or less. More preferably, the distance between the ventilation zone and the upstream end of the hollow tubular segment of the aerosol cooling element is approximately 4 millimeters or less.

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

The distance between the ventilation zone and the mouthpiece end of the aerosol-generating article is preferably approximately 26 millimeters or less. More preferably, the distance between the ventilation zone and the mouthpiece end of the aerosol-generating article is approximately 24 millimeters or less. Even more preferably, the distance between the ventilation zone and the mouthpiece end of the aerosol-generating article is approximately 22 millimeters or less. In particularly preferred embodiments, the distance between the ventilation zone and the mouthpiece end of the aerosol-generating article is approximately 20 millimeters or less.

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

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

The distance between the ventilation zone and the downstream end of the current collector is preferably at least approximately 6 millimeters. More preferably, the distance between the ventilation zone and the downstream end of the current collector is at least approximately 8 millimeters. Even more preferably, the distance between the ventilation zone and the downstream end of the current collector is at least approximately 10 millimeters.

The distance between the ventilation zone and the downstream end of the current collector can be from 9 millimeters to 10 millimeters.

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

The distance between the ventilation zone and the downstream end of the current collector is preferably approximately 20 millimeters or less. More preferably, the distance between the ventilation zone and the downstream end of the current collector is approximately 18 millimeters or less. Even more preferably, the distance between the ventilation zone and the downstream end of the current collector is approximately 16 millimeters or less.

The aerosol-generating article of the present invention may have a ventilation level of at least approximately 5 percent. The term "ventilation level" may also refer to "percent ventilation."

The term "ventilation level" is used throughout this description to denote the volumetric ratio between the airflow admitted to the aerosol-generating device through the ventilation zone (ventilation airflow) and the sum of the aerosol-containing airflow and the ventilation airflow. The higher the ventilation level, the greater the dilution of the aerosol flow delivered to the consumer.

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

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

The aerosol-generating article according to the present invention preferably has a ventilation level of approximately 45 percent or less. More preferably, the aerosol-generating article according to the present invention has a ventilation level of approximately 40 percent or less, and even more preferably, approximately 35 percent or less.

In particularly preferred embodiments, the aerosol generating article has a ventilation level of approximately 30 percent.

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

Without being limited by theory, the present inventors have found that the temperature difference caused by the introduction of cooler external air into the hollow tubular segment through the ventilation zone can have a beneficial effect on the nucleation and growth of aerosol particles.

The formation of an aerosol from a gaseous mixture containing various chemical compounds depends on the subtle interplay of nucleation, evaporation, condensation, and droplet coalescence, while simultaneously accounting for changes in vapor concentration, temperature, and velocity fields. The so-called classical nucleation theory is based on the assumption that a fraction of molecules in the gas phase is large enough to remain cohesive for a long time with a reasonable probability (e.g., 50/50 probability). These molecules represent a kind of critical threshold molecular clusters among short-lived molecular aggregates, meaning that, in general, smaller molecular clusters in the gas phase are more likely to disintegrate quickly, while larger clusters are generally more likely to grow. Such a critical cluster is identified as the key nucleation nucleus, from which droplet growth is expected due to the condensation of molecules from the vapor. Primary droplets, which have just formed, are assumed to emerge with a certain initial diameter and can then grow by several orders of magnitude. This is simplified and can be accelerated by rapid cooling of the surrounding vapor, which causes condensation. This helps to consider that evaporation and condensation are two sides of the same mechanism: mass transfer between gas and liquid. While evaporation refers to the net mass transfer from liquid droplets to the gas phase, condensation is the net mass transfer from the gas phase to the droplet phase. Evaporation (or condensation) will cause a decrease in volume (or growth) of droplets, but will not change the number of droplets.

In this scenario, which may be further complicated by droplet coalescence, temperature and cooling rate may play a significant role in determining the system's response. In general, different cooling rates may lead to significantly different temporal behavior regarding liquid phase (droplet) formation, as the nucleation process is typically nonlinear. Without being limited by theory, it is hypothesized that cooling may cause a rapid decrease in droplet number concentration, followed by a strong, short-term increase in droplet growth (nucleation burst). This nucleation burst may be more significant at lower temperatures. Furthermore, it may be that higher cooling rates may promote an earlier onset of nucleation. In contrast, a decrease in the cooling rate may have a beneficial effect on the final size that aerosol droplets ultimately attain.

Thus, the rapid cooling caused by introducing outside air into the hollow tubular segment through the ventilation zone can be beneficially used to promote the nucleation and growth of aerosol droplets. However, a direct disadvantage of introducing outside air into the hollow tubular segment is the dilution of the aerosol stream delivered to the consumer.

The inventors of the present invention have surprisingly discovered that the effect of dilution on the aerosol, which can be assessed by measurement, in particular the effect on the delivery of the aerosol-forming substance (such as glycerol) contained in the aerosol-forming substrate, is advantageously minimized when the ventilation level is within the ranges described above. In particular, it was found that ventilation levels from 20 percent to 70 percent, preferably from 25 percent to 50 percent, and even more preferably from 28 to 42 percent lead to particularly satisfactory glycerol delivery values. At the same time, the nucleation time and, consequently, the delivery of nicotine and the aerosol-forming substance (e.g., glycerol) are improved.

The present inventors have surprisingly discovered how the beneficial effect of improved nucleation, facilitated by rapid cooling caused by the introduction of ventilation air into the product, can significantly counteract the less desirable effects of dilution. As such, satisfactory aerosol delivery values are consistently achieved by aerosol-generating products according to the present invention.

This is particularly advantageous for "short" aerosol-generating articles, such as articles in which the length of the aerosol-forming substrate rod is less than about 40 millimeters, preferably less than 25 millimeters, even more preferably less than 20 millimeters, or in which the overall length of the aerosol-generating article is less than about 70 millimeters, preferably less than about 60 millimeters, even more preferably less than 50 millimeters. It should be understood that in such aerosol-generating articles, there is little time and space for the aerosol to form and for the particulate phase of the aerosol to be available for delivery to the consumer.

Furthermore, since the ventilated hollow tubular element does not substantially affect the overall RTD of the aerosol-generating article in aerosol-generating articles, in accordance with the present invention, the overall RTD of the article can be advantageously precisely controlled by adjusting the length and density of the aerosol-generating substrate rod, or the length and optionally the length and density of the filter material segment forming part of the mouthpiece, or the length and density of the filter material segment provided upstream of the aerosol-generating substrate and the susceptor. Thus, aerosol-generating articles that have a given RTD can be manufactured consistently and with great accuracy, so that satisfactory RTD levels can be ensured for the consumer even in the presence of ventilation.

In aerosol-generating articles according to the present invention, the overall RTD of the article depends substantially on the RTD of the rod and optionally on the RTD of the mouthpiece and/or upstream rod. This is because the hollow tubular segment of the aerosol cooling element and the hollow tubular segment of the support element are essentially empty and, as a result, have essentially only a minor impact on the overall RTD of the aerosol-generating article.

In practice, the hollow tubular segment of the aerosol cooling element may be adapted to generate an RTD in the range from about 0 millimeters of water (about 0 Pa) to about 20 millimeters of water (about 200 Pa). Preferably, the hollow tubular segment of the aerosol cooling element is adapted to generate an RTD from about 0 millimeters of water (about 0 Pa) to about 10 millimeters of water (about 100 Pa).

The downstream section of the aerosol-generating articles according to the present invention preferably comprises an intermediate hollow section containing a support element aligned with and downstream of the aerosol-forming substrate rod. In particular, the support element may be positioned immediately downstream of the aerosol-forming substrate rod and may be adjacent to the aerosol-forming substrate rod.

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; corrugated paper, such as corrugated heat-resistant paper or corrugated parchment paper; 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 element is positioned substantially in alignment with the rod. This means that the length of the support element is approximately parallel to the longitudinal direction of the rod and the article, for example, within plus or minus 10 degrees parallel to the longitudinal direction of the rod. In preferred embodiments, the support element extends along the longitudinal axis of the rod.

The support member preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol-forming substrate rod and the outer diameter of the aerosol-generating article.

The support element may have an outer diameter of 5 millimeters to 12 millimeters, such as 5 millimeters to 10 millimeters or 6 millimeters to 8 millimeters. In a preferred embodiment, the support element has an outer diameter of 7.2 millimeters plus or minus 10 percent. The support element may have a length of 5 millimeters to 15 millimeters. In a preferred embodiment, the support element has a length of 8 millimeters.

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

The support member may have a length of from approximately 5 millimeters to approximately 15 millimeters.

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

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

In a preferred embodiment, the support member has a length of approximately 8 millimeters.

The ratio between the length of the support member and the length of the aerosol-forming substrate rod may be from about 0.25 to about 1.

Preferably, the ratio between the length of the support element and the length of the aerosol-forming substrate rod is at least about 0.3, more preferably at least about 0.4, even more preferably at least about 0.5. In preferred embodiments, the ratio between the length of the support element and the length of the aerosol-forming substrate rod 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 rod of the 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 rod of the 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 rod of the 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 particularly preferred embodiments, the ratio between the length of the support member and the length of the aerosol-forming substrate rod is approximately 0.66.

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

Preferably, the ratio between the length of the support element and the total length of the substrate of the aerosol-generating article 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 total length of the substrate of the aerosol-generating article 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 total length of the substrate of the aerosol-generating article 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 support element and the total length of the substrate of the aerosol-generating article 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 total length of the substrate of the aerosol-generating article 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 total length of the substrate of the aerosol generating article is approximately 0.18.

Preferably, in the aerosol-generating articles according to the present invention, the support element has an average radial hardness of at least about 80 percent, more preferably at least about 85 percent, and even more preferably at least about 90 percent. Consequently, the support element is capable of providing the desired level of hardness to the aerosol-generating article.

If desired, the radial hardness of the support member of the aerosol-generating articles according to the present invention can be further increased by surrounding the support member with a rigid filament, for example, a filament having a basis weight of at least about 80 grams per square meter (g/ ^m2 ), or at least about 100 g/ ^m2 , or at least about 110 g/ ^m2 .

When inserting an aerosol-generating article according to the present invention into an aerosol-generating device, the user may be required to apply some force to overcome the resistance of the aerosol-generating article's aerosol-generating substrate during insertion. This may damage one or both of the aerosol-generating article and the aerosol-generating device. Furthermore, applying force when inserting the aerosol-generating article into the aerosol-generating device may displace the aerosol-generating substrate within the aerosol-generating article. This may result in improper alignment of the aerosol-generating device's heating element with the susceptor provided within the aerosol-generating substrate, which may lead to uneven and ineffective heating of the aerosol-generating substrate of the aerosol-generating article. The support element is preferably configured to resist movement of the aerosol-forming substrate further downstream during insertion of the article into the aerosol-generating device.

In aerosol-generating articles according to the present invention, the overall RTD of the article depends substantially on the RTD of the rod and optionally on the RTD of the mouthpiece and/or upstream rod. This is because the hollow tubular segment of the aerosol cooling element and the hollow tubular segment of the support element are essentially empty and, as a result, have essentially only a minor impact on the overall RTD of the aerosol-generating article.

In practice, the hollow tubular segment of the support member may be adapted to generate an RTD in the range from about 0 millimeters of water (about 0 Pa) to about 20 millimeters of water (about 200 Pa). Preferably, the hollow tubular segment of the support member is adapted to generate an RTD from about 0 millimeters of water (about 0 Pa) to about 10 millimeters of water (about 100 Pa).

In some embodiments, wherein the downstream section comprises both a support member comprising a first hollow tubular segment and an aerosol cooling member comprising a second hollow tubular segment, such that the support member and the aerosol cooling member together define an intermediate hollow section, wherein the inner diameter (D _STS ) of the second hollow tubular segment is preferably larger than the inner diameter (D _FTS ) of the first hollow tubular segment.

In more detail, the ratio between the inner diameter ( _DSTS ) of the second hollow tubular segment and the inner diameter ( _DFTS ) of the first hollow tubular segment is preferably at least about 1.25. More preferably, the ratio between the inner diameter ( _DSTS ) of the second hollow tubular segment and the inner diameter ( _DFTS ) of the first hollow tubular segment is preferably at least about 1.3. Even more preferably, the ratio between the inner diameter ( _DSTS ) of the second hollow tubular segment and the inner diameter ( _DFTS ) of the first hollow tubular segment is preferably at least about 1.4. In particularly preferred embodiments, the ratio between the inner diameter ( _DSTS ) of the second hollow tubular segment and the inner diameter ( _DFTS ) of the first hollow tubular segment is at least about 1.5, more preferably at least about 1.6.

The ratio between the inner diameter ( _DSTS ) of the second hollow tubular segment and the inner diameter ( _DFTS ) of the first hollow tubular segment is preferably approximately 2.5 or less. More preferably, the ratio between the inner diameter ( _DSTS ) of the second hollow tubular segment and the inner diameter ( _DFTS ) of the first hollow tubular segment is preferably approximately 2.25 or less. Even more preferably, the ratio between the inner diameter ( _DSTS ) of the second hollow tubular segment and the inner diameter ( _DFTS ) of the first hollow tubular segment is preferably approximately 2 or less.

In those embodiments in which the article further comprises an elongated current collector located longitudinally within the aerosol-forming substrate, the ratio between the inner diameter (D _FTS ) of the first hollow tubular segment and the width of the current collector is preferably at least about 0.2. More preferably, the ratio between the inner diameter (D _FTS ) of the first hollow tubular segment and the width of the current collector is at least about 0.3. Even more preferably, the ratio between the inner diameter (D _FTS ) of the first hollow tubular segment and the width of the current collector is at least about 0.4.

Additionally, or alternatively, the ratio between the inner diameter ( _DSTS ) of the second hollow tubular segment and the width of the current collector is preferably at least about 0.2. More preferably, the ratio between the inner diameter ( _DSTS ) of the second hollow tubular segment and the width of the current collector is at least about 0.5. Even more preferably, the ratio between the inner diameter ( _DSTS ) of the second hollow tubular segment and the width of the current collector is at least about 0.8.

Preferably, the ratio between the cavity volume of the first hollow tubular segment and the cavity volume of the second hollow tubular segment is at least approximately 0.1. More preferably, the ratio between the cavity volume of the first hollow tubular segment and the cavity volume of the second hollow tubular segment is at least approximately 0.2. Even more preferably, the ratio between the cavity volume of the first hollow tubular segment and the cavity volume of the second hollow tubular segment is at least approximately 0.3.

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

In preferred embodiments, the downstream section of the aerosol generating articles of the present invention comprises an intermediate hollow section having both the aerosol cooling member described above and the support member described above.

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

The downstream section of the aerosol-generating article according to the present invention preferably comprises a mouthpiece element. The mouthpiece element is preferably located at the downstream end, or mouthpiece end, of the aerosol-generating article. The mouthpiece element preferably comprises at least one mouthpiece filter segment for filtering the aerosol generated from 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 those skilled in the art. Particularly preferably, at least one mouthpiece filter segment comprises a cellulose acetate filter segment formed from a cellulose acetate rod.

In certain preferred embodiments, the mouthpiece element consists of a single filtering mouthpiece segment. In alternative embodiments, the mouthpiece element comprises two or more filtering mouthpiece segments coaxially aligned end-to-end.

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

The mouthpiece may optionally contain a flavoring agent, which may be provided in any suitable form. For example, the mouthpiece may contain one or more capsules, beads, or granules of flavoring agent, or one or more threads or fibers filled with a flavoring agent.

In the aerosol generating article according to the present invention, the mouthpiece element forms part of a downstream section and is therefore positioned downstream of the aerosol generating substrate rod.

In certain preferred embodiments, the downstream section of the aerosol-generating article further comprises a support element positioned immediately downstream of the aerosol-forming substrate rod. A mouthpiece element is positioned downstream of the support element. Preferably, the downstream section further comprises an aerosol cooling element positioned immediately downstream of the support element. The mouthpiece element is preferably positioned downstream of both the support element and the aerosol cooling element. Particularly preferably, the mouthpiece element is positioned immediately downstream of the aerosol cooling element. As an example, the mouthpiece element may be adjacent to the downstream end of the aerosol cooling element.

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

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

Preferably, the mouthpiece is surrounded by a wick. Preferably, the mouthpiece is not ventilated, so that air does not enter the aerosol-generating product along the mouthpiece.

The mouthpiece element is preferably connected to one or more adjacent upstream components of the aerosol generating article via a rim wrap.

Preferably, the mouthpiece element has an RTD of less than about 25 millimeters of water. More preferably, the mouthpiece element has an RTD of less than about 20 millimeters of water. Even more preferably, the mouthpiece element has an RTD of less than about 15 millimeters of water.

RTD values of approximately 10 millimeters of water column to approximately 15 millimeters of water column are particularly preferred since a mouthpiece element having one such RTD, which makes a minimal contribution to the overall RTD of the aerosol-generating article, is expected to have substantially no filtering effect on the aerosol delivered to the consumer.

The mouthpiece element preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol-generating article. The mouthpiece element may have an outer diameter of approximately 5 millimeters to approximately 10 millimeters, or approximately 6 millimeters to approximately 8 millimeters. In a preferred embodiment, the mouthpiece element has an outer diameter of approximately 7.2 millimeters.

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

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

For example, the mouthpiece element may have a length of approximately 5 millimeters to approximately 25 millimeters, or from approximately 8 millimeters to approximately 20 millimeters, or from approximately 10 millimeters to approximately 15 millimeters. In a preferred embodiment, the mouthpiece element has a length of approximately 12 millimeters.

In certain preferred embodiments of the present invention, the mouthpiece element has a length of at least 10 millimeters. Therefore, 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 aerosol-generating articles according to the present invention can provide several advantages for the consumer. The mouthpiece element is generally more resistant to deformation or better adapted to recovering its original shape after deformation than other elements that may be provided downstream of the aerosol-forming substrate rod, such as an aerosol cooling element or a support element. Therefore, increasing the length of the mouthpiece element provides improved grip by the consumer and facilitates insertion of the aerosol-generating article into a heating device. A longer mouthpiece can be used to provide higher levels of filtration and remove unwanted aerosol components, such as phenols, to deliver a higher-quality aerosol. Furthermore, using a longer mouthpiece allows for a more complex mouthpiece, as more space is left for incorporating mouthpiece components such as capsules, strings, and stoppers.

In particularly preferred embodiments of the present invention, a mouthpiece at least 10 millimeters long is combined with a relatively short aerosol cooling element, such as an aerosol cooling element less than 10 millimeters long. This combination has been found to provide a more rigid mouthpiece, reducing the risk of deformation of the aerosol cooling element during use and promoting more efficient puffing by the consumer.

The ratio between the length of the mouthpiece element and the length of the aerosol-forming substrate rod 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 aerosol-forming substrate rod is at least about 0.6, more preferably at least about 0.7, even more preferably at least about 0.8. In preferred embodiments, the ratio between the length of the mouthpiece element and the length of the aerosol-forming substrate rod 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 rod of the 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 rod of the 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 rod of the 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 particularly preferred embodiments, the ratio between the length of the mouthpiece element and the length of the aerosol-forming substrate rod is approximately 1.

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

Preferably, the ratio between the length of the mouthpiece element and the total length of the substrate of the aerosol-generating article 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 total length of the substrate of the aerosol-generating article 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 total length of the substrate of the aerosol-generating article 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 total length of the substrate of the aerosol-generating article 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 total length of the substrate of the aerosol-generating article 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 total length of the substrate of the aerosol generating article is approximately 0.27.

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

The aerosol-generating article according to the present invention preferably comprises an upstream element located upstream of and adjacent to the aerosol-generating 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-generating substrate. In particular, when the aerosol-generating substrate comprises a susceptor element, the upstream element can prevent direct physical contact with the upstream end of the susceptor element. This helps prevent displacement or deformation of the susceptor element during handling or transportation of the aerosol-generating article. This, in turn, helps maintain the shape and position of the susceptor element. In addition, the presence of the upstream element helps prevent any loss of substrate, which can be advantageous, for example, if the substrate contains particulate plant material.

The upstream element may also provide an enhanced 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 brand, flavor, content, or information about the aerosol-generating device with which the article is intended.

The upstream element may be a porous rod-shaped element. Preferably, the porous rod-shaped element does not change the draw resistance of the aerosol-generating article. Preferably, the upstream element has a porosity of at least approximately 50 percent in the longitudinal direction of the aerosol-generating article. More preferably, the upstream element has a porosity of from approximately 50 percent to approximately 90 percent in the longitudinal direction. The porosity of the upstream element in the longitudinal direction is determined by the ratio of the cross-sectional area of the material forming the upstream element and the internal cross-sectional area of the aerosol-generating article at the position of the upstream element.

The upstream element may be made of a porous material or may contain multiple holes. This can be achieved, for example, by laser perforation. Preferably, the multiple holes are uniformly distributed across the cross-section of the upstream element.

The porosity or permeability of the upstream element can advantageously be varied to provide the desired overall draw resistance of the aerosol generating article.

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

The RTD of the upstream element is preferably less than or equal to about 80 millimeters of water. More preferably, the RTD of the upstream element is less than or equal to about 60 millimeters of water. Even more preferably, the RTD of the upstream element is less than or equal to about 40 millimeters of water.

In some embodiments, the RTD of the upstream element is from about 5 millimeters of water to about 80 millimeters of water, preferably from about 10 millimeters of water to about 80 millimeters of water, more preferably from about 15 millimeters of water to about 80 millimeters of water, even more preferably from about 20 millimeters of water to about 80 millimeters of water. In other embodiments, the RTD of the upstream element is from about 5 millimeters of water to about 60 millimeters of water, preferably from about 10 millimeters of water to about 60 millimeters of water, more preferably from about 15 millimeters of water to about 60 millimeters of water, even more preferably from about 20 millimeters of water. to about 60 millimeters of water column. In further embodiments, the RTD of the upstream element is from about 5 millimeters of water column to about 40 millimeters of water column, preferably from about 10 millimeters of water column to about 40 millimeters of water column, more preferably from about 15 millimeters of water column to about 40 millimeters of water column, even more preferably from about 20 millimeters of water column to about 40 millimeters of water column.

In alternative embodiments, the upstream element may be formed from an air-impermeable material. In such embodiments, the aerosol-generating article may be designed such that air flows into the aerosol-generating substrate rod through suitable venting means provided in the wrapper.

The upstream element may be made of any material suitable for use in an aerosol-generating article. The upstream element may be made, for example, of the same material used for one of the other components of the aerosol-generating article, such as a mouthpiece, a cooling element, or a support element. Suitable materials for forming the upstream element include filter materials, ceramics, polymeric material, cellulose acetate, cardboard, zeolite, or an aerosol-forming substrate. Preferably, the upstream element is formed from a cellulose acetate rod.

Preferably, the upstream element is made of a heat-resistant material. For example, the upstream element is preferably made of a material that can withstand 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 upstream element has a diameter that is approximately equal to the diameter of the aerosol generating article.

Preferably, the upstream element has a length of from about 1 millimeter to about 10 millimeters, more preferably from about 3 millimeters to about 8 millimeters, more preferably from about 4 millimeters to about 6 millimeters. In a particularly preferred embodiment, the upstream element has a length of about 5 millimeters. The length of the upstream element can advantageously be varied to provide the desired overall length of the aerosol-generating article. For example, if it is desired to reduce the length of one of the other components of the aerosol-generating article, the length of the upstream element can be increased to maintain the overall length of the article at the same level.

The upstream element preferably has a substantially uniform structure. For example, the upstream element may have a substantially uniform texture and appearance. The upstream element may, for example, have a continuous, flat surface across its entire cross-section. The upstream element may, for example, have no recognizable symmetries.

The upstream element is preferably surrounded by a wrapper. The wrapper surrounding the upstream element is preferably a rigid filament, such as a filament having a basis weight of at least about 80 grams per square meter (g/ ^m2 ), or at least about 100 g/ ^m2 , or at least about 110 g/ ^m2 . This provides structural rigidity to the upstream element.

The aerosol generating article may have a length ranging from approximately 35 millimeters to approximately 100 millimeters.

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

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

In some embodiments, the overall length of the aerosol-generating article is preferably from about 38 millimeters to about 70 millimeters, more preferably from about 40 millimeters to about 70 millimeters, even more preferably from about 42 millimeters to about 70 millimeters. In other embodiments, the overall length of the aerosol-generating article is preferably from about 38 millimeters to about 60 millimeters, more preferably from about 40 millimeters to about 60 millimeters, even more preferably from about 42 millimeters to about 60 millimeters. In further embodiments, the overall length of the aerosol-generating article is preferably from about 38 millimeters to about 50 millimeters, more preferably from about 40 millimeters to about 50 millimeters, even more preferably from about 42 millimeters to about 50 millimeters. In an exemplary embodiment, the overall length of the aerosol generating article is approximately 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 millimeters. More preferably, the aerosol-generating article has an outer diameter of at least 7 millimeters.

Preferably, the aerosol-generating article has an outer diameter of less than or equal to approximately 12 millimeters. More preferably, the aerosol-generating article has an outer diameter of less than or equal to approximately 10 millimeters. Even more preferably, the aerosol-generating article has an outer diameter of less than or equal to approximately 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 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 further embodiments, the aerosol-generating article has an outer diameter of about 5 millimeters to about 8 millimeters, preferably about 6 millimeters to about 8 millimeters, more preferably about 7 millimeters to about 8 millimeters.

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

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

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

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

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

By way of example, the outer diameter of the article may be substantially constant over a distal portion of the article extending from the distal end of the aerosol-generating article by at least approximately 5 millimeters or at least approximately 10 millimeters. Alternatively, the outer diameter of the article may taper over a distal portion of the article extending from the distal end by at least approximately 5 millimeters or at least approximately 10 millimeters.

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

Preferably, the center of mass is no more than approximately 70 percent of the way along the length of the aerosol generating article from the downstream end.

Ensuring an arrangement of elements such that the center of mass is closer to the upstream end than to the downstream end results in the aerosol-generating device having a weight imbalance with the heavier upstream end. This weight imbalance can advantageously provide tactile feedback to the user, allowing them to distinguish between the upstream and downstream ends so that the correct end can be inserted into the aerosol-generating device. This can be particularly useful when an upstream element is provided, such that the upstream and downstream ends of the aerosol-generating device are visually similar.

In embodiments of aerosol-generating articles according to the present invention, where both the aerosol-cooling element and the support element are present, they are preferably wrapped together in a combined wrapper. The combined wrapper surrounds the aerosol-cooling element and the support element, but does not surround any further downstream elements, such as the mouthpiece.

In these embodiments, the aerosol cooling element and the support element are combined before being surrounded by the combined wrapper, before they are further combined with the mouthpiece segment.

From a manufacturing standpoint, this is advantageous because it allows shorter aerosol-generating products to be assembled.

In general, processing individual elements whose length is shorter than their diameter can be challenging. For example, for elements with a diameter of 7 millimeters, a length of approximately 7 millimeters represents a threshold value that is preferable not to approach. However, a 10 millimeter aerosol cooling element can be combined with a pair of 7 millimeter support elements on each side (and possibly with other elements, such as an aerosol-forming substrate rod, etc.) to produce a 24 millimeter hollow segment, which is then cut into two intermediate 12 millimeter hollow sections.

In particularly preferred embodiments, the other components of the aerosol-generating article are individually wrapped. In other words, the upstream element, the aerosol-forming substrate rod, the support element, and the aerosol-cooling element are individually wrapped. The support element and the aerosol-cooling element are combined to form an intermediate hollow section. This is achieved by wrapping the support element and the aerosol-cooling element with a combined wrapper. The upstream element, the aerosol-forming substrate rod, and the intermediate hollow section are then combined with the outer wrapper. Accordingly, they are combined with the mouthpiece element, which has its own wrapper, using tipping paper.

Preferably, at least one of the components of the aerosol generating article is wrapped in a hydrophobic wrapper.

The term "hydrophobic" refers to a surface that exhibits water-repellent properties. One common method for determining this property is by measuring the water contact angle. The water contact angle is the angle, typically measured using a liquid, where the liquid/vapor interface meets a solid surface. Quantitatively, it represents the wettability of the solid surface by the liquid, according to Young's equation. Hydrophobicity, or water contact angle, can be determined using TAPPI Test Method T558, and the result is reported as the contact angle at the interface, expressed in degrees, which can range from approximately zero to approximately 180 degrees.

In preferred embodiments, 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 contain PVOH (polyvinyl alcohol) or silicon. PVOH may be applied to the paper layer as a surface coating, or the paper layer may be surface treated with PVOH or silicon.

In a particularly preferred embodiment, the aerosol-generating article according to the present invention comprises, in a linear sequential arrangement, an upstream element, an aerosol-forming substrate rod positioned immediately downstream of the upstream element, a support element positioned immediately downstream of the aerosol-forming substrate rod, an aerosol-cooling element positioned immediately downstream of the support element, a mouthpiece element positioned immediately downstream of the aerosol-cooling element, and an outer wrapper surrounding the upstream element, the support element, the aerosol-cooling element, and the mouthpiece element.

In more detail, the aerosol-forming substrate rod may be adjacent to an upstream element. The support element may be adjacent to the aerosol-forming substrate rod. The aerosol-cooling element may be adjacent to the support element. The mouthpiece element may be adjacent to the aerosol-cooling element.

The aerosol-generating article has a substantially cylindrical shape and an outer diameter of approximately 7.25 millimeters. The perimeter of the aerosol-generating article is preferably between 20 millimeters and 23 millimeters, more preferably between 21 millimeters and 22 millimeters.

The upstream element is approximately 5 millimeters long, the aerosol-generating rod is approximately 12 millimeters long, the support element is approximately 8 millimeters long, and the mouthpiece is approximately 12 millimeters long. Thus, the total length of the aerosol-generating device is approximately 45 millimeters.

The upstream element is in the form of a cellulose acetate rod wrapped in a rigid fibreglass.

The aerosol-generating article comprises an elongated current collector located substantially longitudinally within the aerosol-generating substrate rod and in thermal contact with the aerosol-generating substrate. The current collector is shaped like a strip or plate, has a length substantially equal to the length of the aerosol-generating substrate rod, and a thickness of approximately 60 micrometers.

The support element is shaped like a hollow acetate cellulose tube and has an internal diameter of approximately 1.9 millimeters. Therefore, the thickness of the peripheral wall of the support element is approximately 2.675 millimeters.

The aerosol cooling element is shaped like a thinner, hollow cellulose acetate tube and has an internal diameter of approximately 3.25 millimeters. Therefore, the peripheral wall thickness of the aerosol cooling element is approximately 2 millimeters.

The mouthpiece is shaped as a filter segment made of low density cellulose acetate.

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

The following is a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

Example A: An aerosol-generating article containing:

aerosol generating substrate rod;

a ventilation zone located further downstream of the aerosol-generating substrate rod;

wherein the ventilation zone comprises perforations, wherein one or more of the perforations have a non-circular cross-section having ovality, wherein the ovality is a ratio of the large diameter of the perforation hole to the small diameter of the perforation hole of at least 1.5, and wherein the thickness of the peripheral wall of the ventilation zone is from 0.1 millimeters to 2.5 millimeters.

Example B: An aerosol-generating article according to example A, wherein one or more of the perforations have an oval cross-section.

Example C: An aerosol generating article according to any of the previous examples, wherein one or more of the perforations are in the form of a slit.

Example D: An aerosol-generating article according to any of the preceding examples, wherein for one or more of the perforations, the length of the perforations is greater than the width of the perforations.

Example E: An aerosol-generating article according to any of the previous examples, wherein for one or more of the perforations, the longitudinal axis of the perforation is parallel to the longitudinal axis of the aerosol-generating article.

Example F: An aerosol generating article according to any of the previous examples, wherein one or more perforations have a width of from 0.05 millimeters to 0.2 millimeters, preferably from 0.1 millimeters to 0.15 millimeters, most preferably from 0.11 millimeters to 0.13 millimeters.

Example G: An aerosol generating article according to any of the previous examples, wherein one or more perforations have a length of from 0.25 millimeters to 1.0 millimeters, preferably from 0.4 millimeters to 0.8 millimeters, most preferably from 0.5 millimeters to 0.6 millimeters.

Example H: An aerosol generating article according to any of the previous examples, wherein the ovality of the perforations is at least 2, preferably at least 3, more preferably at least 4, most preferably at least 5.

Example I: An aerosol generating article according to any of the previous examples, in which 10 to 12 perforations are provided, preferably the number of perforations being 11.

Example J: An aerosol-generating article according to any of the previous examples, in which each perforation has a central axis, wherein the aerosol-generating article has a central axis, and wherein the smallest distance between the central axis of each perforation and the central axis of the aerosol-generating article is from 3% to 15% of the outer diameter of the aerosol-generating article, preferably from 4% to 13% of the outer diameter of the aerosol-generating article, more preferably from 5% to 10% of the outer diameter of the aerosol-generating article, most preferably 6% of the outer diameter of the aerosol-generating article.

Example K: An aerosol-generating article according to any of the previous examples, wherein each central axis of each perforation is located at an angle relative to the radial direction of the aerosol-generating article of from 3° to 20°, preferably at an angle of from 4° to 15°, more preferably at an angle of from 5° to 10°, most preferably at an angle of 7°.

Example L: An aerosol generating article according to any of the previous examples, wherein the ventilation zone is formed as a hollow tubular ventilation zone, and wherein the inner diameter of the hollow tubular ventilation zone is from 2.5 millimeters to 5.0 millimeters, preferably from 3.0 millimeters to 4.0 millimeters, more preferably from 3.1 millimeters to 3.5 millimeters, most preferably 3.3 millimeters.

Example M: An aerosol generating article according to any of the previous examples, wherein the ventilation zone is located in the second hollow tubular segment of the aerosol cooling element, and wherein the second hollow tubular segment has an internal volume of from 130 mm ³ to 200 mm ³ , preferably from 155 mm ³ to 185 mm ³ , more preferably 170 mm ³ .

Example N: An aerosol generating article according to any of the previous examples, in which the perforations are located in the peripheral wall of the ventilation zone, preferably the perforations have a non-constant pitch with a pitch variation coefficient of more than 5%.

Example O: An aerosol generating article according to the previous example, wherein the thickness of the peripheral wall of the ventilation zone is from 0.8 millimeters to 2.2 millimeters, more preferably from 1.2 millimeters to 1.8 millimeters, most preferably about 1.5 millimeters.

Example P: An aerosol generating article according to any of the preceding examples, wherein the perforations are arranged in a row.

Example Q: An aerosol generating article according to any of the previous examples, wherein the distance between the perforations of the ventilation zone and the downstream end of the aerosol generating substrate rod is from 1 millimeter to 6 millimeters, preferably from 2 millimeters to 5 millimeters, more preferably from 3 millimeters to 4 millimeters.

Example R: An aerosol-generating article according to any of the previous examples, wherein the distance between the perforations of the ventilation zone and the downstream end of the aerosol-generating article is from 10 millimeters to 26 millimeters, preferably from 12 millimeters to 24 millimeters, more preferably from 14 millimeters to 22 millimeters, most preferably from 16 millimeters to 20 millimeters.

Example S: An aerosol generating article according to any of the previous examples, wherein the perforations are configured to allow ambient air to be drawn into the ventilation zone.

Example T: An aerosol-generating article according to the previous example, in which the ratio between the ambient air drawn into the ventilation zone through the perforations and the air drawn into the ventilation zone through the rod of the aerosol-forming substrate is from 5 percent to 75 percent, preferably from 20 percent to 65 percent, more preferably from 30 percent to 60 percent, more preferably from 40 percent to 55 percent, most preferably 50 percent.

Example U: An aerosol-generating article according to any of the previous examples, wherein the aerosol-generating article further comprises a filter rod located downstream of the ventilation chamber, wherein the retraction resistance of the filter rod is from 5 millimeters of water to 80 millimeters of water, preferably from 10 millimeters of water to 65 millimeters of water, more preferably from 15 millimeters of water to 50 millimeters of water, more preferably from 20 millimeters of water to 40 millimeters of water, most preferably 30 millimeters of water.

Example V: An aerosol generating system comprising an aerosol generating device having a cavity for receiving an aerosol generating article according to any of the previous examples.

Example W: A method for manufacturing an aerosol generating article, wherein the method comprises the steps of:

providing an aerosol-generating substrate rod;

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

creating non-circular perforation holes in the peripheral wall of the ventilation zone, having ovality, wherein the ovality is a ratio of the large diameter of the perforation hole to the small diameter of the perforation hole, which is at least 1.5, and wherein the thickness of the peripheral wall of the ventilation zone is from 0.1 millimeter to 2.5 millimeters.

Example X: An aerosol-generating article that may comprise a rod of aerosol-forming substrate. The aerosol-generating article may further comprise a ventilation zone located downstream of the rod of aerosol-forming substrate. The ventilation zone may comprise from 5 to 15 perforations, preferably from 7 to 14 perforations, more preferably from 9 to 13 perforations, more preferably from 10 to 12 perforations, most preferably 11 perforations.

Example Y: An aerosol-generating article that may comprise a rod of aerosol-generating substrate. The aerosol-generating article may further comprise a ventilation zone located downstream of the rod of aerosol-generating substrate. The ventilation zone may comprise perforations. The perforations may be located in the peripheral wall of the ventilation zone. The perforations may have a variable pitch with a coefficient of pitch variation greater than 5%.

The present invention will now be further described with reference to

Fig. 1, which shows a schematic cross-sectional side view of an aerosol generating article in accordance with the present invention;

Fig. 2, which shows a cross-sectional view of the aerosol generating article in the ventilation zone position; and

Fig. 3, which shows a non-circular perforation hole in the ventilation zone.

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

The aerosol generating product has an overall length of approximately 45 millimetres.

The downstream section 14 comprises a support member 22 positioned immediately downstream of the aerosol-forming substrate rod 12, wherein the support member 22 is in longitudinal alignment with the rod 12. In the embodiment of Fig. 1, the upstream end of the support member 18 is adjacent to the downstream end of the aerosol-forming substrate rod 12. The downstream section 14 further comprises an aerosol cooling element 24 positioned immediately downstream of the support member 22, wherein the aerosol cooling element 24 is in longitudinal alignment with the rod 12 and the support member 22. In the embodiment of Fig. 1, the upstream end of the aerosol cooling element 24 is adjacent to the downstream end of the support member 22.

As will be apparent from the following description, the support member 22 and the aerosol cooling member 24 together define an intermediate hollow section 50 of the aerosol-generating article 10. Overall, the intermediate hollow section 50 does not contribute significantly to the overall RTD of the aerosol-generating article. The RTD of the intermediate hollow section 26 as a whole is substantially 0 mm H2O.

The support member 22 comprises a first hollow tubular segment 26. The first hollow tubular segment 26 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The first hollow tubular segment 26 defines an internal cavity 28 that extends the entire distance from the upstream end 30 of the first hollow tubular segment to the downstream end 32 of the first hollow tubular segment 20. The internal cavity 28 is substantially empty, and therefore a substantially unrestricted air flow along the internal cavity 28 is possible. The first hollow tubular segment 26 and, as a result, the support member 22 do not make a significant contribution 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 member 22) is substantially 0 millimeters of water.

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

The aerosol cooling element 24 comprises a second hollow tubular segment 34. The second hollow tubular segment 34 is in the form of a hollow cylindrical tube made of cellulose acetate. The second hollow tubular segment 34 defines an internal cavity 36 that extends the entire distance from the upstream end 38 of the second hollow tubular segment to the downstream end 40 of the second hollow tubular segment 34. The internal cavity 36 is substantially empty, and therefore a substantially unrestricted air flow along the internal cavity 36 is possible. The second hollow tubular segment 28 and, as a result, the aerosol cooling element 24, do not make a significant contribution to the overall RTD of the aerosol generating article 10. In more detail, the RTD of the second hollow tubular segment 34 (which is essentially the RTD of the aerosol cooling element 24) is substantially 0 millimeters of water. Art.

The second hollow tubular segment 34 has a length of approximately 8 millimeters, an outer diameter of approximately 7.25 millimeters, and an inner diameter ( _DSTS ) of approximately 3.25 millimeters. Thus, the thickness of the peripheral wall of the second hollow tubular segment 34 is approximately 2 millimeters. Thus, the ratio between the inner diameter ( _DSTS ) of the first hollow tubular segment 26 and the inner diameter ( _DSTS ) of the second hollow tubular segment 34 is approximately 0.75.

The aerosol generating article 10 comprises a ventilation zone 60 provided at a location along the second hollow tubular segment 34. In more detail, the ventilation zone is provided at a distance of approximately 2 millimeters from the upstream end of the second hollow tubular segment 34. The ventilation level of the aerosol generating article 10 is approximately 25 percent.

In the embodiment of Fig. 1, the downstream section 14 further comprises 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 image of Fig. 1, the upstream end of the mouthpiece element 42 is adjacent to the downstream end 40 of the aerosol cooling element 18.

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

The mouthpiece element 42 has a length of approximately 12 millimeters and an outer diameter of approximately 7.25 millimeters. The RTD of the mouthpiece element 42 is approximately 12 millimeters of water.

Rod 12 contains an aerosol-forming substrate of one of the types described above.

The aerosol-forming substrate rod 12 has an outer diameter of approximately 7.25 millimeters and a length of approximately 12 millimeters.

The aerosol-generating article 10 further comprises an elongated current collector 44 within the rod 12 of the aerosol-forming substrate. In more detail, the current collector 44 is located substantially longitudinally within the aerosol-forming substrate in such a way as to be approximately parallel to the longitudinal direction of the rod 12. As shown in the image of Fig. 1, the current collector 44 is located in a radially central position within the rod and extends substantially along the longitudinal axis of the rod 12.

The current collector 44 extends the entire distance from the upstream end to the downstream end of the rod 12. In fact, the current collector 44 has essentially the same length as the rod 12 of the aerosol-forming substrate.

In the embodiment of Fig. 1, the current collector 44 is provided in the form of a strip and has a length of approximately 12 millimeters, a thickness of approximately 60 micrometers and a width of approximately 4 millimeters. The upstream section 16 comprises an upstream element 46, located immediately upstream of the rod 12 of the aerosol-forming substrate, wherein the upstream element 46 is in longitudinal alignment with the rod 12. In the embodiment of Fig. 1, the downstream end of the upstream element 46 is adjacent to the upstream end of the rod 12 of the aerosol-forming substrate. This advantageously prevents the current collector 44 from shifting. In addition, this ensures that the consumer cannot accidentally touch the heated current collector 44 after use.

Upstream element 46 is in the form of a cylindrical rod of cellulose acetate surrounded by a rigid wrapper. Upstream element 46 has a length of approximately 5 millimeters. The RTD of upstream element 46 is approximately 30 millimeters of water column.

In Fig. 2, perforation openings 62 are shown in the ventilation zone 60. The ventilation zone 60 is provided at a location along the second hollow tubular segment 34. The perforation openings 62 are located in the peripheral wall of the hollow tubular segment 34. The perforation openings 62 are arranged in a row around the peripheral wall of the hollow tubular segment 34. The perforation openings 62 are configured to allow ambient air to flow into the internal cavity 36. In Fig. 2, it is shown that 11 perforation openings are provided in the peripheral wall of the hollow tubular segment 34. It has been found that this number of perforation openings 62 is particularly useful for creating an aerosol.

Fig. 3 shows a non-circular perforation 62. The perforation 62 has an ovality with a length L that is significantly greater than the width W of the perforation 62. The length of the perforation 62 runs parallel to the central axis of the aerosol-generating article.

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

Claims (19)

1. An aerosol generating article comprising: aerosol generating substrate rod; a ventilation zone located further downstream of the aerosol-generating substrate rod; wherein the ventilation zone comprises perforations, wherein one or more of the perforations have a non-circular cross-section having ovality, wherein the ovality is a ratio of the major diameter of the perforation to the minor diameter of the perforation of at least 1.5, wherein one or more of the perforations have an oval cross-section, wherein the thickness of the peripheral wall of the ventilation zone is from 0.1 millimeter to 2.5 millimeters, wherein one or more of the perforations have a width of from 0.05 millimeter to 0.2 millimeters, preferably from 0.1 millimeter to 0.15 millimeters, most preferably from 0.11 millimeter to 0.13 millimeters, wherein one or more of the perforations have a length of from 0.25 millimeters to 1.0 millimeters, preferably from 0.4 millimeters to 0.8 millimeters, most preferably from 0.5 millimeters to 0.6 millimeters. 2. An aerosol generating article according to claim 1, characterized in that one or more of the perforation openings have the shape of a slit. 3. An aerosol generating article according to any one of the preceding claims, characterized in that for one or more of the perforations, the length of the perforations is greater than the width of the perforations, preferably wherein for one or more of the perforations, the longitudinal axis of the perforation is parallel to the longitudinal axis of the aerosol generating article. 4. An aerosol generating article according to any one of the preceding claims, characterized in that the ovality of the perforations is at least 2, preferably at least 3, more preferably at least 4, most preferably at least 5. 5. An aerosol generating article according to any one of the preceding claims, characterized in that the ventilation zone is formed as a hollow tubular ventilation zone, and wherein the internal diameter of the hollow tubular ventilation zone is from 2.5 millimeters to 5.0 millimeters, preferably from 3.0 millimeters to 4.0 millimeters, more preferably from 3.1 millimeters to 3.5 millimeters, most preferably 3.3 millimeters. 6. An aerosol generating article according to any one of the preceding claims, characterized in that the ventilation zone is located in a hollow tubular segment of the aerosol cooling element, and wherein the hollow tubular segment has an internal volume of from 130 mm ³ to 200 mm ³ , preferably from 155 mm ³ to 185 mm ³ , more preferably 170 mm ³ . 7. An aerosol generating article according to any one of the preceding claims, characterized in that the distance between the perforations of the ventilation zone and the downstream end of the aerosol generating substrate rod is from 1 millimeter to 6 millimeters, preferably from 2 millimeters to 5 millimeters, more preferably from 3 millimeters to 4 millimeters. 8. An aerosol generating article according to any one of the preceding claims, characterized in that the distance between the perforations of the ventilation zone and the downstream end of the aerosol generating article is from 10 millimeters to 26 millimeters, preferably from 12 millimeters to 24 millimeters, more preferably from 14 millimeters to 22 millimeters, most preferably from 16 millimeters to 20 millimeters. 9. An aerosol generating article according to any one of the preceding claims, characterized in that the perforations are configured to allow ambient air to be drawn into the ventilation zone, preferably wherein the ratio between the ambient air drawn into the ventilation zone through the perforations and the air drawn into the ventilation zone through the rod of the aerosol-forming substrate is from 5 percent to 75 percent, preferably from 20 percent to 65 percent, more preferably from 30 percent to 60 percent, more preferably from 40 percent to 55 percent, most preferably 50 percent. 10. An aerosol-generating article according to any one of the preceding claims, characterized in that the aerosol-generating article further comprises a filter rod located downstream of the ventilation zone, wherein the draw resistance of the filter rod is from 5 millimeters of water to 80 millimeters of water, preferably from 10 millimeters of water to 65 millimeters of water, more preferably from 15 millimeters of water to 50 millimeters of water, more preferably from 20 millimeters of water to 40 millimeters of water, most preferably 30 millimeters of water. 11. An aerosol-generating article according to any one of the preceding claims, characterized in that the aerosol-generating article further comprises a substrate wrapper at least partially surrounding the aerosol-forming substrate rod, and wherein the substrate wrapper has a thickness of 50 micrometers or more, preferably 65 micrometers or more, more preferably 80 micrometers or more. 12. An aerosol generating system comprising an aerosol generating device having a cavity for receiving an aerosol generating article according to any one of the preceding claims. 13. A method for manufacturing an aerosol-generating article, wherein the method comprises the steps of: providing an aerosol-generating substrate rod; providing a ventilation zone downstream of the aerosol generating substrate rod; and creating non-circular perforations in a peripheral wall of a ventilation zone that have ovality, wherein the ovality is a ratio of the major diameter of the perforation to the minor diameter of the perforation of at least 1.5, wherein one or more of the perforations have an oval cross-section, wherein the thickness of the peripheral wall of the ventilation zone is from 0.1 millimeter to 2.5 millimeters, wherein one or more of the perforations have a width of from 0.05 millimeter to 0.2 millimeters, preferably from 0.1 millimeter to 0.15 millimeters, most preferably from 0.11 millimeter to 0.13 millimeters, wherein one or more of the perforations have a length of from 0.25 millimeters to 1.0 millimeters, preferably from 0.4 millimeters to 0.8 millimeters, most preferably from 0.5 millimeters to 0.6 millimeters.