RU2826034C1 - Aerosol-generating article comprising substrate with gel composition - Google Patents

Abstract

FIELD: smoking accessories.

SUBSTANCE: invention relates to an aerosol-generating article. Aerosol-generating article (10) for producing an inhaled aerosol when heated comprises: rod (12) of an aerosol-generating substrate containing a gel composition, wherein the gel composition contains at least one gelling agent, at least one of an alkaloid compound and a cannabinoid compound, and an aerosol-forming substance; mouthpiece (42); and intermediate hollow section (50) between the aerosol-generating substrate rod and the mouthpiece. Intermediate hollow section (50) comprises aerosol cooling element (24) located in axial alignment with mouthpiece element and adjacent to the upstream end of mouthpiece element (42), wherein aerosol cooling element (24) comprises hollow tubular segment (34) having a length of less than 10 millimetres and forming a longitudinal cavity providing a channel for unlimited flow, wherein the flow channel is empty. Intermediate hollow section (50) further comprises support element (22) located downstream of aerosol-generating substrate rod (12), wherein said support element comprises hollow tubular segment (26) to make longitudinal cavity (28) to allow unlimited flow.

EFFECT: providing high-efficiency cooling at a shorter distance due to the presence of the second empty hollow segment.

14 cl, 1 dwg, 1 tbl

Description

The present invention relates to an aerosol generating article comprising an aerosol generating substrate and adapted to produce an inhalable aerosol upon heating.

Aerosol-generating articles in which an aerosol-generating substrate, such as a tobacco-containing substrate, is heated rather than burned 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 that 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.

In a number of prior art documents, aerosol generating devices for consuming aerosol generating articles are disclosed. 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, which comprise an internal heating plate, which is adapted to be inserted into an aerosol generating substrate. As an alternative, inductively heated aerosol generating articles have been proposed in WO 2015/176898, comprising an aerosol generating substrate and a current collecting element, located inside the aerosol generating substrate.

Aerosol-generating articles in which the tobacco-containing substrate is heated rather than combusted create a number of problems that have not been encountered with conventional smoking articles. First, the tobacco-containing substrates are typically heated to significantly lower temperatures than those reached by the combustion front in a conventional cigarette. This may 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 must be cooled to a greater extent and more quickly before it reaches the consumer. However, technical solutions that are widely used to cool the mainstream smoke in conventional smoking articles, such as the provision of a highly efficient filtration segment at the mouth end of a cigarette, may have undesirable effects on an aerosol-generating article in which the tobacco-containing substrate is heated rather than combusted, as they may reduce nicotine delivery. Secondly, there is a fundamental need for aerosol generating products that are easy to use and have improved usability.

It would therefore be desirable to provide a new and improved aerosol generating article adapted to achieve at least one of the desired results described above. It would also be desirable to provide such an aerosol generating article that could be manufactured efficiently and at high speed, preferably with a satisfactory RTD and low RTD variability from one article to another.

The present invention relates to an aerosol-generating article comprising a rod of an aerosol-generating substrate. The rod of the aerosol-generating substrate may comprise a gel composition. The gel composition may comprise at least one gelling agent, at least one of an alkaloid compound and a cannabinoid compound, and an aerosol-forming substance. The aerosol-generating article may further comprise a mouthpiece element. The aerosol-generating article may comprise an intermediate hollow section between the rod of the aerosol-generating substrate and the mouthpiece element. The intermediate hollow section may comprise an aerosol-cooling element downstream of the rod of the aerosol-generating substrate. The aerosol cooling element may comprise a hollow tubular segment having a length of less than 10 millimeters and forming a longitudinal cavity providing a channel for unrestricted flow.

According to the present invention, an aerosol generating article is provided for producing an inhalable aerosol upon heating, wherein the aerosol generating article comprises: a rod of an aerosol generating substrate containing a gel composition, wherein the gel composition contains at least one gelling agent, at least one of an alkaloid compound and a cannabinoid compound, and an aerosol forming substance; a mouthpiece element; and an intermediate hollow section between the rod of the aerosol generating substrate and the mouthpiece element. The intermediate hollow section comprises an aerosol cooling element located in axial alignment with the mouthpiece element and adjacent to an upstream end of the mouthpiece element, wherein the aerosol cooling element comprises a hollow tubular segment having a length of less than 10 millimetres and forming a longitudinal cavity providing a channel for unrestricted flow.

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

A conventional cigarette is lit when a user applies a flame to one end of the cigarette and draws air through the other end. The localized heat provided by the flame and the oxygen in the air drawn through the cigarette causes the end of the cigarette to ignite, and the resulting combustion generates inhaled smoke. In comparison, in heated aerosol-generating articles, the aerosol is generated by heating a flavor-generating substrate, such as tobacco. Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles in which the aerosol is generated by transferring heat from a heat-producing combustible element or heat source to a physically separate aerosol-generating material. For example, the aerosol generating articles according to the present invention find particular application in aerosol generating systems comprising an electrically heated aerosol generating device having an internal heater plate which is adapted to be inserted into a rod of a substrate generating the aerosol. Aerosol generating articles of this type are described in the prior art, for example in document EP 0 822 670.

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.

In the context of this document, the term "longitudinal" refers to the direction corresponding to the major longitudinal axis of the aerosol-generating article that extends between the upstream and downstream ends of the aerosol-generating article. In the context of this document, the terms "upstream" and "downstream" describe the relative positions of elements or portions of elements of the aerosol-generating article with respect 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 article in the longitudinal direction. The term "cross" refers to the direction that is perpendicular to the longitudinal axis. Any reference to a "section" of the aerosol-generating article or a component of the aerosol-generating article refers to the cross-section unless otherwise specified.

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

In the context of this document, the term "hollow tubular segment" is used to designate a substantially elongated element that defines 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 that has a substantially cylindrical cross-section and that defines at least one air flow channel that establishes 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 segment may be possible. The hollow tubular segment is a separate, discrete element of the aerosol-generating article that has a specific length and thickness.

In the context of this document, the term "elongated" means that the 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.

In the context of the present invention, the hollow tubular segment provides a channel for unrestricted flow. This means that the hollow tubular segment provides a low level of resistance to draw (RTD). Therefore, the flow channel must be free of any components that can restrict the air flow in the longitudinal direction. Preferably, the flow channel is substantially empty.

Thus, the aerosol generating article according to the present invention provides a new configuration of elements comprising a combination of an aerosol generating substrate containing a gel composition with an aerosol cooling element made of a hollow tubular segment having a length of less than 10 millimetres. It was found that this combination of elements provides optimal delivery of the aerosol to the consumer during use.

The use of an aerosol generating substrate formed by a gel composition to form an aerosol upon heating is desirable because it creates a uniform substrate that can generate a highly stable aerosol.

The aerosol generating article comprises an aerosol cooling element which has a length of less than 10 millimetres and is therefore relatively short compared to aerosol cooling elements of aerosol generating articles of the prior art. This reduction in the length of the aerosol cooling element compared to known aerosol cooling elements is made possible by the design of the aerosol cooling element as a hollow tubular segment. The hollow tubular segment forms an internal cavity with a relatively large volume, which ensures highly efficient cooling and nucleation of the aerosol during use. Consequently, sufficient cooling and nucleation of the aerosol can be ensured over a relatively short distance, so that the length of the aerosol cooling element can be shorter than is usually possible with other designs of the aerosol cooling element.

Reducing the length of the aerosol cooling element provides a number of potential technical advantages. The aerosol cooling element typically has a lower resistance to deformation than the mouthpiece element. Thus, reducing the length of the aerosol cooling element reduces the risk of deformation of the aerosol-generating article due to compression during use. In addition, reducing the length of the aerosol cooling element can provide a low cost to the manufacturer, since the cost of a hollow tubular segment is typically higher per unit length than the cost of a mouthpiece element.

Preferably, the reduction in the length of the aerosol cooling element can be compensated by an increase in the length of the mouthpiece element. It has been found that the combination of a mouthpiece element of increased length and an aerosol cooling element of reduced length allows to form a more rigid mouthpiece element in the aerosol generating article according to the present invention. Thus, the aerosol generating article is able to provide greater resistance to radial compression at a location towards the end of the article located downstream of the flow. Preferably, this advantage can be provided without compromising the overall length of the article, so that an overall length can be maintained that corresponds to existing aerosol generating articles.

According to the present invention, an aerosol generating article is provided for generating an inhalable aerosol upon heating. The aerosol generating article comprises a rod of a substrate generating an aerosol. The aerosol generating article further comprises a downstream section at a location downstream of the rod of the substrate generating an aerosol. The downstream section may comprise one or more downstream elements.

In the aerosol-generating article according to the present invention, the downstream section comprises a mouthpiece element. The mouthpiece element may extend to the mouthpiece end of the aerosol-generating article. The downstream section further comprises an intermediate hollow section between the mouthpiece element and the rod of the aerosol-generating substrate. The intermediate hollow section comprises an aerosol-cooling element. The aerosol-cooling element comprises a hollow tubular segment. The intermediate hollow section may further comprise a support element, which may comprise a hollow tubular segment.

In some embodiments, the aerosol-generating article may comprise a ventilation zone at a location along the downstream section. In more detail, the aerosol-generating article may comprise a ventilation zone at a location along the aerosol-cooling element. In preferred embodiments, the aerosol-cooling element comprises or has the shape of a hollow tubular segment, wherein a ventilation zone is provided at a location along the hollow tubular segment of the aerosol-cooling element.

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

The aerosol-generating article may further comprise a current-receiving element within the aerosol-generating substrate. In some embodiments, the current-receiving element may be an elongated current-receiving element. In preferred embodiments, the current-receiving element extends in the longitudinal direction within the aerosol-generating substrate.

These elements of the aerosol generating product will be described in more detail below.

As defined above, the downstream section of the aerosol-generating article according to the present invention comprises a mouthpiece element. The mouthpiece element is preferably arranged 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-generating substrate. For example, the mouthpiece element may comprise one or more segments of fibrous filter material. Suitable fibrous filter materials will be known to a person 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 filter mouthpiece segment. In alternative embodiments, the mouthpiece element comprises two or more filter mouthpiece segments coaxially aligned end-to-end with one another.

Preferably, the mouthpiece element comprises a mouthpiece filter segment having a length of at least about 10 millimeters, more preferably at least about 11 millimeters, more preferably at least about 12 millimeters.

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

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

The mouthpiece element is preferably arranged downstream of the aerosol cooling element. Particularly preferably, the mouthpiece element is arranged immediately downstream of the aerosol cooling element. As an example, the mouthpiece element can be adjacent to the downstream end of the aerosol cooling element.

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

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

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

RTD values of from about 10 millimeters of water column to about 15 millimeters of water column are particularly preferred since a mouthpiece element having one such RTD value, 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 about 5 millimeters to about 10 millimeters or about 6 millimeters to about 8 millimeters. In a preferred embodiment, the mouthpiece element has an outer diameter of about 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 about 5 millimeters to about 25 millimeters, more preferably about 8 millimeters to about 25 millimeters, even more preferably about 10 millimeters to about 25 millimeters. In other embodiments, the mouthpiece element preferably has a length of about 5 millimeters to about 10 millimeters, more preferably about 8 millimeters to about 20 millimeters, even more preferably about 10 millimeters to about 20 millimeters. In further embodiments, the mouthpiece element preferably has a length of about 5 millimeters to about 15 millimeters, more preferably about 8 millimeters to about 15 millimeters, even more preferably about 10 millimeters to about 15 millimeters.

For example, the mouthpiece element may have a length of about 5 millimeters to about 25 millimeters, or about 8 millimeters to about 20 millimeters, or about 10 millimeters to about 15 millimeters. In a preferred embodiment, the mouthpiece element has a length of about 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 the articles of the prior art. Providing a relatively long mouthpiece element in the aerosol-generating articles according to the present invention can provide several advantages for the consumer. The mouthpiece element is usually more resistant to deformation or better adapted to restore its original shape after deformation than other elements that may be provided downstream of the aerosol-generating substrate rod, such as an aerosol cooling element or a support element. Therefore, increasing the length of the mouthpiece element provides an improved grip by the consumer and facilitates insertion of the aerosol-generating article into the heating device. A longer mouthpiece can be optionally used to provide a higher level of filtration and remove unwanted aerosol components such as phenols, so that a higher quality aerosol can be delivered. Additionally, using a longer mouthpiece allows for a more complex mouthpiece, as there is more space to incorporate mouthpiece components such as capsules, strings, and stoppers.

In particularly preferred embodiments of the present invention, a mouthpiece element having a length of at least 10 millimeters is combined with a relatively short aerosol cooling element having a length of less than 10 millimeters. It has been found that this combination provides the aerosol generating article with a more rigid mouthpiece end, which reduces the risk of deformation of the aerosol cooling element during use and facilitates a more efficient puff by the consumer.

Preferably, the length of the mouthpiece element is at least 0.4 of the total length of the intermediate hollow section, 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 ratio between the length of the mouthpiece element and the total length of the intermediate hollow section is thus at least about 0.4, preferably at least about 0.5, more preferably at least about 0.6 and most preferably at least about 0.7.

The ratio between the length of the mouthpiece element and the length of the aerosol generating 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-generating 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-generating 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 aerosol-generating substrate rod 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 aerosol-generating substrate rod 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 aerosol-generating substrate rod 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-generating 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.

As described above, the downstream section of the aerosol generating articles according to the present invention further comprises an intermediate hollow section comprising an aerosol cooling element located in alignment with and downstream of the aerosol generating substrate rod.

The aerosol cooling element is arranged substantially in alignment with the rod. This means that the length dimension of the aerosol cooling element is arranged approximately parallel to the longitudinal direction of the rod and the article, for example, in the range of 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.

In the aerosol generating articles according to the present invention, the aerosol cooling element is formed as a hollow tubular segment which defines a cavity extending over the entire distance from the upstream end of the aerosol cooling element to the downstream end of the aerosol cooling element. Preferably, a ventilation zone is provided at a location along the hollow tubular segment.

The inventors of the present invention have found that satisfactory cooling of the aerosol flow generated by heating an aerosol generating substrate and drawn through one such aerosol cooling element is achieved by providing a ventilation zone at a location along the hollow tubular segment. Furthermore, the inventors of the present invention have found that, as will be described in more detail below, by arranging the ventilation zone at a precisely determined 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 believed that since the temperature of the aerosol stream is rapidly reduced by introducing ventilation air as the aerosol moves toward the mouthpiece segment, and the ventilation air is introduced into the aerosol stream at a location relatively close to the upstream end of the aerosol cooling element (i.e., sufficiently close to the current collecting element extending inside the rod of the aerosol generating substrate, which is a heat source during use), a sharp cooling of the aerosol stream is achieved, which has a beneficial effect on the condensation and nucleation of aerosol particles. Accordingly, the overall ratio of the particulate aerosol phase to the gas phase of the aerosol can be improved compared to existing non-ventilated aerosol generating articles.

At the same time, by maintaining a relatively small thickness of the peripheral wall of the hollow tubular segment, it is ensured that the total internal volume of the hollow tubular element, which becomes available for the aerosol to begin the nucleation process immediately after the aerosol components leave the rod of the aerosol generating substrate, and the cross-sectional surface area of the hollow tubular segment are effectively maximized, while at the same time it is ensured that the hollow tubular segment has sufficient structural strength to prevent the aerosol generating article from being compressed, as well as to provide some support for the rod of the aerosol generating substrate and to minimize the RTD of the hollow tubular segment. It is understood that large values of the cross-sectional surface area of the cavity of the hollow tubular segment are associated with a decrease in the flow velocity of the aerosol moving along the aerosol generating article, which is also expected to favor the nucleation of the aerosol. In addition, by using a hollow tubular segment having a relatively small thickness, it has been found that it is possible to essentially prevent the diffusion of ventilation air before it comes into contact and mixes with the aerosol flow, which, as is understood, further promotes nucleation phenomena. In practice, by providing more controllably localized cooling of the vaporized compound flow, the effect of cooling on the formation of new aerosol particles can be enhanced.

The aerosol cooling element preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol generating 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 about 2 millimeters. More preferably, the hollow tubular segment of the aerosol cooling element has an internal diameter of at least about 2.5 millimeters. Even more preferably, the hollow tubular segment of the aerosol cooling element has an internal diameter of at least about 3 millimeters.

The hollow tubular segment of the aerosol cooling element preferably has a wall thickness of less than about 2.5 millimeters, preferably less than about 1.5 millimeters, more preferably less than about 1250 micrometers, even more preferably less than about 1000 micrometers. In particularly preferred embodiments, the hollow tubular segment of the aerosol cooling element has a wall thickness of less than about 900 micrometers, preferably less than about 800 micrometers.

In one embodiment, the hollow tubular segment of the aerosol cooling element has a wall thickness of approximately 2 millimeters.

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

In preferred embodiments, the aerosol cooling element has a length of less than about 12 millimeters, more preferably less than about 10 millimeters.

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

In particularly preferred embodiments of the present invention, the aerosol cooling element has a length of less than 10 millimeters. For example, in one particularly preferred embodiment, the aerosol cooling element has a length of 8 millimeters. Therefore, in such embodiments, the aerosol cooling element has a relatively short length compared to aerosol cooling elements of aerosol-generating articles of the known art. The reduction in 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. The reduction in the length of the aerosol cooling element advantageously reduces the risk of deformation of the aerosol-generating article due to compression during use, since the aerosol cooling element generally has a lower resistance to deformation than the mouthpiece. Additionally, reducing the length of the aerosol cooling element can provide a low cost to the manufacturer, as the cost of a hollow tubular segment is typically higher per unit length than the cost of other elements such as a mouthpiece element.

The ratio between the length of the aerosol cooling element and the length of the aerosol generating 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 generating 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 generating 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 aerosol cooling element and the length of the rod of the aerosol generating 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 aerosol cooling element and the length of the rod of the aerosol generating 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 aerosol cooling element and the length of the rod of the aerosol generating 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 aerosol cooling element and the length of the aerosol generating substrate rod is approximately 0.66.

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.

In some 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 0.3, 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.

In a particularly preferred embodiment, 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 may advantageously allow increasing the length of other elements of the aerosol generating article, such as the mouthpiece element. Potential technical advantages of providing a relatively long mouthpiece element are described above.

The ratio between the length of the aerosol cooling element and the length of the aerosol generating 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 generating 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 generating 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 aerosol cooling element and the length of the rod of the aerosol generating 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 aerosol cooling element and the length of the rod of the aerosol generating 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 aerosol cooling element and the length of the rod of the aerosol generating 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 aerosol cooling element and the length of the aerosol generating substrate rod is 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.

In some 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 0.3, 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.

In a particularly preferred embodiment, 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 may advantageously allow increasing the length of other elements of the aerosol generating article, such as the mouthpiece element. 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, even more preferably at least about 90 percent. Accordingly, 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 .

In the context of this document, the term "radial hardness" of an element refers to the resistance to compression in the direction transverse to the longitudinal axis of the element. The radial hardness of an aerosol-generating article around an element can be determined by applying a load along the article at a location of the element transverse to the longitudinal axis of the article and measuring the average (mean) compressed diameters of the articles. The radial hardness is determined as follows:

Radial

where D _S is the original (uncompressed) diameter and D _d is the compressed diameter after a specified load has been applied for a specified period of time. The harder the material, the closer the hardness is to 100 percent.

In order to determine the hardness of a part (such as an aerosol cooling element provided in the form of a hollow tubular segment) of an aerosol article, the aerosol-generating articles shall be aligned parallel in a plane, and the same part of each aerosol-generating article to be tested shall be subjected to a specified load for a specified period of time. This test is carried out using a known densimetric device DD60A (manufactured and marketed by Heinr Borgwaldt Gmbh, Germany), equipped with a measuring head for aerosol-generating articles such as cigarettes and a container for an aerosol-generating article.

The load is applied by means of two cylindrical load application shafts that traverse the diameter of all the aerosol-generating articles simultaneously. The standard test method for this measuring device is to conduct the test so that twenty points of contact are created between the aerosol-generating articles and the cylindrical load application shafts. In some cases, the hollow tubular segments to be tested may be long enough that only ten aerosol-generating articles are required to create the twenty points of contact, with each smoking article in contact with both load application shafts (because they are long enough to pass between the shafts). In other cases, if the support members are too short to achieve this, twenty aerosol-generating articles should be used to create the twenty points of contact, with each aerosol-generating article in contact with only one of the load application shafts, as discussed further below.

Two additional stationary cylindrical shafts are located below the aerosol generating articles to support the aerosol generating articles and to counteract the load applied by each of the cylindrical shafts to apply the load.

In the standard operating mode for such a device, a total load of 2 kg is applied for 20 seconds. After 20 seconds (and while the load is still applied to the smoking articles), the depression of the cylindrical shafts for applying the load is determined, and this value is then used to calculate the hardness according to the above equation. The temperature is maintained at about 22 degrees Celsius ± 2 degrees. The above test is called the DD60A test. The standard method for measuring filter hardness is carried out when the aerosol-generating article is not consumed. Additional information regarding the measurement of average radial hardness can be found, for example, in published publication of the US patent application No. 2016/0128378.

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.

Preferably, the hollow tubular segment of the aerosol cooling element is adapted to generate an RTD of from about 0 millimeters of water column (about 0 Pa) to about 20 millimeters of water column (about 100 Pa), more preferably from about 0 millimeters of water column (about 0 Pa) to about 10 millimeters of water column (about 100 Pa).

In the aerosol-generating articles according to the present invention, the overall RTD of the article depends essentially on the RTD of the rod and optionally on the RTD of the mouthpiece and/or the upstream plug. 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, essentially only slightly affect the overall RTD of the aerosol-generating article.

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.

The aerosol generating article of the present invention may have a ventilation level of at least about 5 percent.

The term "ventilation level" is used throughout this specification to refer to the volumetric ratio between the airflow admitted into the aerosol-generating article 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.

The aerosol generating article may typically have a ventilation level of at least about 10 percent, preferably at least about 15 percent, more preferably at least about 20 percent.

In preferred embodiments, the ventilation level of the aerosol-generating article is at least about 25 percent. The aerosol-generating article preferably has a ventilation level of less than about 60 percent. The aerosol-generating article of the present invention preferably has a ventilation level of about 45 percent or less. More preferably, the aerosol-generating article of the present invention has a ventilation level of about 40 percent or less, even more preferably about 35 percent or less.

In particularly preferred embodiments, the aerosol-generating article has a ventilation level of about 30 percent. In some embodiments, the aerosol-generating article has a ventilation level of about 20 percent to about 60 percent, preferably about 20 percent to about 45 percent, more preferably about 20 percent to about 40 percent. In other embodiments, the aerosol-generating article has a ventilation level of about 25 percent to about 60 percent, preferably about 25 percent to about 45 percent, more preferably about 25 percent to about 40 percent. In further embodiments, the aerosol-generating article has a ventilation level of about 30 percent to about 60 percent, preferably about 30 percent to about 45 percent, more preferably about 30 percent to about 40 percent.

In particularly preferred embodiments, the aerosol-generating article has a ventilation level of 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 a temperature difference caused by the admission of cooler outside air into the hollow tubular segment through a 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 interactions of nucleation, evaporation and condensation, and droplet coalescence, while taking into account 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 coherent for a long time with a sufficient probability (e.g. fifty-fifty probability). These molecules represent some 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 enough, while larger clusters are, in general, more likely to grow. Such a critical cluster is identified with the key nucleation nucleus from which droplet growth is expected due to condensation of molecules from the vapor. Primary droplets that have just formed are assumed to appear with a certain initial diameter and can then grow by several orders of magnitude. This is simplified and can be accelerated by rapidly cooling the surrounding vapor, which causes condensation. Thus, it helps to consider that evaporation and condensation are two sides of the same mechanism, namely mass transfer between a gas and a liquid. Whereas evaporation refers to a net mass transfer from the liquid droplets to the gas phase, condensation is a net mass transfer from the gas phase to the droplet phase. Evaporation (or condensation) will cause a decrease in volume (or growth) of the droplets, but will not change the number of droplets.

In this scenario, which may be further complicated by droplet coalescence phenomena, temperature and cooling rate may play an important role in determining the response of the system. In general, different cooling rates may result in significantly different time behavior with respect to liquid phase (droplet) formation, since the nucleation process is typically nonlinear. Without being limited by theory, it is suggested 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. It may also be that higher cooling rates may favor 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 eventually reach.

Thus, the rapid cooling caused by the admission of external air into the hollow tubular segment through the ventilation zone can be advantageously used to promote the nucleation and growth of aerosol droplets. However, at the same time, the immediate disadvantage of admitting external 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 found 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 generating substrate) is advantageously minimized when the ventilation level is within the ranges described above. In particular, it has been found that ventilation levels from 25 percent to 50 percent, and even more preferably from 28 to 42 percent, lead to particularly satisfactory values of glycerol delivery. At the same time, the duration of nucleation and, therefore, the delivery of nicotine and the aerosol forming substance (such as glycerol) are improved.

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

This is particularly advantageous for "short" aerosol-generating articles, such as articles in which the length of the aerosol-generating 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.

In addition, since the ventilated hollow tubular segment does not substantially affect the overall RTD of the aerosol-generating article in aerosol-generating articles, according to the present invention, the overall RTD of the article can be advantageously precisely controlled by adjusting the length and density of the rod of the aerosol-generating substrate, or the length and optionally the length and density of the segment of the filter material forming part of the mouthpiece, or the length and density of the segment of the filter material provided upstream of the aerosol-generating substrate and the current-collecting element. In this way, aerosol-generating articles that have a given RTD can be manufactured with high quality and greater accuracy, so that satisfactory RTD levels can be provided to the consumer even in the presence of ventilation.

In some embodiments, the aerosol-generating article may further comprise an additional cooling element defining a plurality of longitudinally extending channels in order to make a high specific surface area available for heat exchange. In other words, one such additional cooling element is adapted to function essentially as a heat exchanger. The plurality of longitudinally extending channels may be defined by a sheet material that has been folded, gathered or bent to form channels. The plurality of longitudinally extending channels may be defined by a single sheet that has been folded, gathered or bent to form multiple channels. The sheet may also be corrugated before being folded, gathered or bent. Alternatively, the plurality of longitudinally extending channels may be defined by multiple sheets that have been corrugated, folded, gathered or bent to form multiple channels. In some embodiments, the plurality of longitudinally extending channels may be defined by several sheets that have been corrugated, pleated, gathered, or folded together, i.e., two or more sheets that are introduced into an overlapping arrangement and then corrugated, pleated, gathered, or folded as one. As used herein, the term "sheet" refers to a laminated element that has a width and a length that are substantially greater than its thickness.

In the context of this document, the term "longitudinal direction" refers to a direction running along or parallel to the axis of the rod cylinder. In the context of this document, the term "corrugated" means a sheet having a plurality of substantially parallel folds or corrugations. Preferably, when the aerosol-generating article is assembled, the substantially parallel folds or corrugations extend in the longitudinal direction relative to the rod. In the context of this document, the terms "gathered", "folded" or "bent" mean that the sheet of material is rolled, bent or otherwise compressed or narrowed substantially in the transverse direction relative to the axis of the rod cylinder. The sheet may be corrugated before being assembled, pleated or folded. The sheet may be gathered, pleated or folded without being pre-corrugated.

One such additional cooling element may have a total surface area from approximately 300 square millimeters per millimeter of length to approximately 1000 square millimeters per millimeter of length.

The additional cooling element preferably has a low resistance to the passage of air through the additional cooling element. Preferably, the additional cooling element does not substantially affect the resistance to draw of the aerosol-generating article. To achieve this, it is preferable that the porosity in the longitudinal direction is more than 50 percent, and that the air flow path through the additional cooling element is relatively free. The longitudinal porosity of the additional cooling element can be determined by the ratio of the cross-sectional area of the material forming the additional cooling element and the internal cross-sectional area of the aerosol-generating article in the part containing the additional cooling element.

The additional cooling element preferably comprises a sheet material selected from the group consisting of a metal foil, a sheet of a polymeric material, and substantially non-porous paper or cardboard. In some embodiments, the aerosol cooling element may comprise a sheet material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), and aluminum foil. In a particularly preferred embodiment, the additional cooling element comprises a sheet of PLA.

As described above, the intermediate hollow section preferably further comprises a support element arranged in alignment with the rod of the aerosol-generating substrate and downstream of it. In particular, the support element may be arranged immediately downstream of the rod of the aerosol-generating substrate and may abut the rod of the aerosol-generating substrate.

The support member may be formed from any suitable material or combination of materials. For example, the support member 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 member is formed from cellulose acetate. Other suitable materials include polyhydroxyalkanoate (PHA) fibers.

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

The support element is preferably arranged substantially in alignment with the rod. This means that the length dimension of the support element is arranged approximately parallel to the longitudinal direction of the rod and the article, for example in the range of 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-generating substrate rod and the outer diameter of the aerosol-generating article.

The support element may have an outside 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 outside diameter of 7.2 millimeters plus or minus 10 percent.

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

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

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

Preferably, the intermediate hollow section has an overall length of no more than about 18 millimeters, more preferably no more than about 17 millimeters, more preferably no more than about 16 millimeters.

The ratio between the length of the support member and the length of the aerosol generating 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-generating 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-generating 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 aerosol-generating substrate rod 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 aerosol-generating substrate rod 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 aerosol-generating substrate rod 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 element and the length of the aerosol generating 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 member has an average radial hardness of at least about 80 percent, more preferably at least about 85 percent, even more preferably at least about 90 percent. Accordingly, the support member 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 ( ^{gsm )} , or at least about 100 gsm, or at least about 110 ^gsm .

During insertion of the aerosol-generating article according to the present invention into the aerosol-generating device, for heating the aerosol-generating substrate, the user may be required to apply some force to overcome the resistance of the aerosol-generating substrate, the aerosol-generating article, for insertion. This may damage one or both of the aerosol-generating article and the aerosol-generating device. In addition, applying force when inserting the aerosol-generating article into the aerosol-generating device may displace the aerosol-generating substrate inside the aerosol-generating article. This may result in improper alignment of the heating element of the aerosol-generating device with the current-receiving element provided inside the aerosol-generating substrate, which may result in uneven and ineffective heating of the aerosol-generating substrate, the aerosol-generating article. The support element is preferably designed to resist movement of the aerosol-generating substrate downstream during insertion of the article into the aerosol-generating device.

Preferably, the hollow tubular segment of the support member is adapted to generate an RTD of from about 0 millimeters of water column (about 0 Pa) to about 20 millimeters of water column (about 100 Pa), more preferably from about 0 millimeters of water column (about 0 Pa) to about 10 millimeters of water column (about 100 Pa). The support member thus preferably does not contribute to the overall RTD of the aerosol-generating article.

In some embodiments, in which the intermediate hollow section comprises both a support member comprising a first hollow tubular segment and an aerosol cooling member comprising a second hollow tubular segment, the inner diameter ( _DSTS ) of the second hollow tubular segment is preferably greater than the inner diameter ( _DFTS ) 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 some 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 from about 1.25 to about 2.5. 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 from about 1.3 to about 2.5. 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 from about 1.4 to about 2.5. 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 from about 1.5 to about 2.5.

In other 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 from about 1.25 to about 2.25. 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 from about 1.3 to about 2.25. 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 from about 1.4 to about 2.25. 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 from about 1.5 to about 2.25.

In further 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 from about 1.25 to about 2. 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 from about 1.3 to about 2. 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 from about 1.4 to about 2. 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 from about 1.5 to about 2.

In those embodiments in which the article further comprises an elongated current-collecting element arranged longitudinally within the aerosol-generating substrate, as described below, the ratio between the inner diameter ( _DFTS ) of the first hollow tubular segment and the width of the current-collecting element is preferably at least about 0.2. More preferably, the ratio between the inner diameter ( _DFTS ) of the first hollow tubular segment and the width of the current-collecting element is at least about 0.3. Even more preferably, the ratio between the inner diameter ( _DFTS ) of the first hollow tubular segment and the width of the current-collecting element 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 collecting element 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 collecting element 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 collecting element 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.

As defined above, the aerosol generating article according to the present invention comprises a rod of aerosol generating substrate. The aerosol generating substrate may be a solid aerosol generating substrate.

According to the present invention, the aerosol-generating substrate comprises a gel composition that comprises an alkaloid compound or a cannabinoid compound, or both an alkaloid compound and a cannabinoid compound. In particularly preferred embodiments, the aerosol-generating substrate comprises a gel composition that comprises nicotine.

Preferably, the gel composition comprises an alkaloid compound or a cannabinoid compound, or both an alkaloid compound and a cannabinoid compound; an aerosol forming agent; and at least one gelling agent. Preferably, the at least one gelling agent forms a solid medium, and the glycerol is distributed in the solid medium, wherein the alkaloid or cannabinoid is distributed in the glycerol. Preferably, the gel composition is a stable gel phase.

Advantageously, a stable gel composition containing nicotine provides a predictable shape of the composition during storage or transportation from production to the consumer. A stable gel composition containing nicotine essentially maintains its shape. A stable gel composition containing nicotine essentially does not release a liquid phase during storage or transportation from production to the consumer. A stable gel composition containing nicotine can provide a simple consumable design. This consumable material can be designed without liquid content, thus a wider range of container materials and designs can be envisaged.

The gel composition described herein may be combined with an aerosol generating device to deliver a nicotine aerosol to the lungs at inhalation or air flow rates that are within the inhalation or air flow rates of a typical smoking regimen. The aerosol generating device may continuously heat the gel composition. The user may take multiple inhalations or "puffs," where each "puff" delivers a certain amount of nicotine aerosol. The gel composition may be capable of delivering a high nicotine/low total particulate matter (TPM) aerosol to the user upon heating, preferably in a continuous manner.

The phrase "stable gel phase" or "stable gel" refers to a gel that substantially maintains its shape and mass when exposed to varying environmental conditions. A stable gel may not substantially release (release moisture) or absorb water when exposed to standard temperature and pressure when the relative humidity changes from about 10 percent to about 60 percent. For example, a stable gel may substantially maintain its shape and mass when exposed to standard temperature and pressure when the relative humidity changes from about 10 percent to about 60 percent.

The gel composition comprises an alkaloid compound or a cannabinoid compound, or both an alkaloid compound and a cannabinoid compound. The gel composition may comprise one or more alkaloids. The gel composition may comprise one or more cannabinoids. The gel composition may comprise a combination of one or more alkaloids and one or more cannabinoids.

The term "alkaloid compound" refers to any of a class of naturally occurring organic compounds that contain one or more basic nitrogen atoms. Typically, an alkaloid contains at least one nitrogen atom in an amine-type structure. This or another nitrogen atom in the alkaloid compound molecule can be active as a base in acid-base reactions. Most alkaloid compounds have one or more nitrogen atoms as part of a cyclic system, such as, for example, a heterocyclic ring. In nature, alkaloid compounds are found primarily in plants and are especially common in certain families of flowering plants. However, some alkaloid compounds are found in animal and fungal species. As used herein, the term "alkaloid compound" refers to both naturally occurring alkaloid compounds and synthetically produced alkaloid compounds.

The gel composition may preferably contain an alkaloid compound selected from the group consisting of nicotine, anatabine and combinations thereof.

Preferably, the gel composition contains nicotine.

The term "nicotine" refers to nicotine and nicotine derivatives such as pure nicotine, nicotine salts, etc.

The term "cannabinoid compound" refers to any of a class of naturally occurring compounds found in parts of the cannabis plant, namely the species Cannabis sativa , Cannabis indica , and Cannabis ruderalis . Cannabinoid compounds are particularly concentrated in the female flower heads. Cannabinoid compounds naturally occurring in the cannabis plant include cannabidiol (CBD) and tetrahydrocannabinol (THC). As used herein, the term "cannabinoid compounds" is used to describe both naturally occurring cannabinoid compounds and synthetically produced cannabinoid compounds.

The gel may contain a cannabinoid compound selected from the group consisting of cannabidiol (CBD), tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), cannabichromene (CBC), cannabicyclol (CBL), cannabivarin (CBV), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabigerol monomethyl ether (CBGM), cannabielsoin (CBE), cannabicitran (CBT) and combinations thereof.

The gel composition may preferably comprise a cannabinoid compound selected from the group consisting of cannabidiol (CBD), THC (tetrahydrocannabinol), and combinations thereof.

The gel may preferably contain cannabidiol (CBD).

The gel composition may contain nicotine and cannabidiol (CBD).

The gel composition may contain nicotine, cannabidiol (CBD) and THC (tetrahydrocannabinol).

The gel composition preferably comprises from about 0.5 percent by weight to about 10 percent by weight of an alkaloid compound, or from about 0.5 percent by weight to about 10 percent by weight of a cannabinoid compound, or both the alkaloid compound and the cannabinoid compound in a total amount of from about 0.5 percent by weight to about 10 percent by weight. The gel composition can comprise from about 0.5 percent by weight to about 5 percent by weight of an alkaloid compound, or from about 0.5 percent by weight to about 5 percent by weight of a cannabinoid compound, or both the alkaloid compound and the cannabinoid compound in a total amount of from about 0.5 percent by weight to about 5 percent by weight. Preferably, the gel composition comprises from about 1 percent by weight to about 3 percent by weight of an alkaloid compound, or from about 1 percent by weight to about 3 percent by weight of a cannabinoid compound, or both the alkaloid compound and the cannabinoid compound in a total amount of from about 1 percent by weight to about 3 percent by weight. The gel composition may preferably comprise from about 1.5 percent by weight to about 2.5 percent by weight of an alkaloid compound, or from about 1.5 percent by weight to about 2.5 percent by weight of a cannabinoid compound, or both the alkaloid compound and the cannabinoid compound in a total amount of from about 1.5 percent by weight to about 2.5 percent by weight. The gel composition may preferably comprise about 2 percent by weight of an alkaloid compound, or about 2 percent by weight of a cannabinoid compound, or both the alkaloid compound and the cannabinoid compound in a total amount of about 2 percent by weight. The alkaloid compound component of the gel composition may be the most volatile component of the gel composition. In some aspects, water may be the most volatile component of the gel composition, and the alkaloid compound component of the gel composition may be the second most volatile component of the gel composition. The cannabinoid compound component of the gel composition may be the most volatile component of the gel composition. In some aspects, water may be the most volatile component of the gel composition, and the alkaloid compound component of the gel composition may be the second most volatile component of the gel composition.

Preferably, nicotine is contained in gel compositions. Nicotine can be added to the composition as a free base or as a salt. The gel composition contains from about 0.5 percent by weight to about 10 percent by weight nicotine, or from about 0.5 percent by weight to about 5 percent by weight nicotine. Preferably, the gel composition contains from about 1 percent by weight to about 3 percent by weight nicotine, or from about 1.5 percent by weight to about 2.5 percent by weight nicotine, or about 2 percent by weight nicotine. The nicotine component of the gel composition may be the most volatile component of the gel composition. In some aspects, water may be the most volatile component of the gel composition, and the nicotine component of the gel composition may be the second most volatile component of the gel composition.

The gel composition further comprises an aerosol forming agent. Ideally, the aerosol forming agent is substantially resistant to thermal decomposition at the operating temperature of the associated aerosol generating device. Suitable aerosol forming agents include, but are not limited to: polyhydric alcohols such as triethylene 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 polyhydric alcohols or mixtures thereof may be one or more of the following: triethylene glycol, 1,3-butanediol and glycerol (glycerol or propane-1,2,3-triol) or polyethylene glycol. The aerosol forming agent is preferably glycerol.

The gel composition may contain a major portion of an aerosol forming agent. The gel composition may contain a mixture of water and an aerosol forming agent, wherein the aerosol forming agent forms a major portion (by weight) of the gel composition. The aerosol forming agent may form at least about 50 percent by weight of the gel composition. The aerosol forming agent may form at least about 60 percent by weight, or at least about 65 percent by weight, or at least about 70 percent by weight of the gel composition. The aerosol forming agent may form from about 70 percent by weight to about 80 percent by weight of the gel composition. The aerosol forming agent may form from about 70 percent by weight to about 75 percent by weight of the gel composition.

The gel composition may contain a majority of glycerol. The gel composition may contain a mixture of water and glycerol, wherein glycerol forms a majority (by weight) of the gel composition. Glycerol may form at least about 50 percent by weight of the gel composition. Glycerol may form at least about 60 percent by weight, or at least about 65 percent by weight, or at least about 70 percent by weight of the gel composition. Glycerol may form from about 70 percent by weight to about 80 percent by weight of the gel composition. Glycerol may form from about 70 percent by weight to about 75 percent by weight of the gel composition.

The gel composition preferably further comprises at least one gelling agent. Preferably, the gel composition comprises a total amount of gelling agents in the range of about 0.4 percent by weight to about 10 percent by weight. More preferably, the composition comprises gelling agents in the range of about 0.5 percent by weight to about 8 percent by weight. More preferably, the composition comprises gelling agents in the range of about 1 percent by weight to about 6 percent by weight. More preferably, the composition comprises gelling agents in the range of about 2 percent by weight to about 4 percent by weight. More preferably, the composition comprises gelling agents in the range of about 2 percent by weight to about 3 percent by weight.

The term "gelling agent" refers to a compound that, when uniformly added to a 50 percent by weight water/50 percent by weight glycerol mixture in an amount of approximately 0.3 percent by weight, forms a solid medium or support matrix that results in the formation of a gel. Gelling agents include, but are not limited to, hydrogen-bonding gelling agents and ionic-bonding gelling agents.

The gelling agent may include one or more biopolymers. The biopolymers may be formed from polysaccharides.

Biopolymers include, for example, gellan gums (natural, low acyl gellan gum, high acyl gellan gums, with low acyl gellan gum being preferred), xanthan gum, alginates (alginic acid), agar, guar gum, etc. The composition may preferably include xanthan gum. The composition may include two biopolymers. The composition may include three biopolymers. The composition may include two biopolymers in substantially equal weights. The composition may include three biopolymers in substantially equal weights.

Preferably, the gel composition comprises at least about 0.2 percent by weight of a gelling agent that provides crosslinking through hydrogen bonds. Alternatively or additionally, the gel composition preferably comprises at least about 0.2 percent by weight of a gelling agent that provides crosslinking through ionic bonds. Most preferably, the gel composition comprises at least about 0.2 percent by weight of a gelling agent that provides crosslinking through hydrogen bonds and at least about 0.2 percent by weight of a gelling agent that provides crosslinking through ionic bonds. The gel composition may comprise from about 0.5 percent by weight to about 3 percent by weight of a gelling agent providing crosslinking through hydrogen bonds and from about 0.5 percent by weight to about 3 percent by weight of a gelling agent providing crosslinking through ionic bonds, or from about 1 percent by weight to about 2 percent by weight of a gelling agent providing crosslinking through hydrogen bonds and from about 1 percent by weight to about 2 percent by weight of a gelling agent providing crosslinking through ionic bonds. The gelling agent providing crosslinking through hydrogen bonds and the gelling agent providing crosslinking through ionic bonds may be present in the gel composition in substantially equal amounts by weight.

The term "hydrogen bonding crosslinking gelling agent" refers to a gelling agent that forms non-covalent crosslinking bonds or physical crosslinking bonds through hydrogen bonding. Hydrogen bonding is a type of dipole-dipole electrostatic attraction between molecules rather than a covalent bond with a hydrogen atom. The result is an attractive force between a hydrogen atom covalently bonded to a very electronegative atom, such as an N, O, or F atom, and another very electronegative atom.

The gelling agent providing crosslinking by means of hydrogen bonds may comprise one or more of galactomannan, gelatin, agarose or konjac gum, or agar. The gelling agent providing crosslinking by means of hydrogen bonds may preferably comprise agar.

The gel composition preferably comprises a gelling agent providing crosslinking by hydrogen bonds in a range of from about 0.3 percent by weight to about 5 percent by weight. Preferably, the composition comprises a gelling agent providing crosslinking by hydrogen bonds in a range of from about 0.5 percent by weight to about 3 percent by weight. Preferably, the composition comprises a gelling agent providing crosslinking by hydrogen bonds in a range of from about 1 percent by weight to about 2 percent by weight.

The gel composition may contain galactomannan in a range of from about 0.2 percent by weight to about 5 percent by weight. Preferably, galactomannan may be in a range of from about 0.5 percent by weight to about 3 percent by weight. Preferably, galactomannan may be in a range of from about 0.5 percent by weight to about 2 percent by weight. Preferably, galactomannan may be in a range of from about 1 percent by weight to about 2 percent by weight.

The gel composition may contain gelatin in a range of about 0.2 percent by weight to about 5 percent by weight. Preferably, the gelatin may be in a range of about 0.5 percent by weight to about 3 percent by weight. Preferably, the gelatin may be in a range of about 0.5 percent by weight to about 2 percent by weight. Preferably, the gelatin may be in a range of about 1 percent by weight to about 2 percent by weight.

The gel composition may contain agarose in a range from about 0.2 percent by weight to about 5 percent by weight. Preferably, the agarose may be in a range from about 0.5 percent by weight to about 3 percent by weight. Preferably, the agarose may be in a range from about 0.5 percent by weight to about 2 percent by weight. Preferably, the agarose may be in a range from about 1 percent by weight to about 2 percent by weight.

The gel composition may contain konjac gum in a range of from about 0.2 percent by weight to about 5 percent by weight. Preferably, konjac gum may be in a range of from about 0.5 percent by weight to about 3 percent by weight. Preferably, konjac gum may be in a range of from about 0.5 percent by weight to about 2 percent by weight. Preferably, konjac gum may be in a range of from about 1 percent by weight to about 2 percent by weight.

The gel composition may contain agar in a range of from about 0.2 percent by weight to about 5 percent by weight. Preferably, the agar may be in a range of from about 0.5 percent by weight to about 3 percent by weight. Preferably, the agar may be in a range of from about 0.5 percent by weight to about 2 percent by weight. Preferably, the agar may be in a range of from about 1 percent by weight to about 2 percent by weight.

The term "ionic crosslinking gelling agent" refers to a gelling agent that forms non-covalent crosslinking bonds or physical crosslinking bonds through the formation of ionic bonds. Ionic crosslinking involves the linking of polymer chains through non-covalent interactions. A crosslinked network is formed when multivalent molecules of opposite charges are electrostatically attracted to each other, resulting in the formation of a crosslinked polymer network.

The gelling agent providing crosslinking by ionic bonds may comprise low acyl gellan, pectin, kappa carrageenan, iota carrageenan or alginate. The gelling agent providing crosslinking by ionic bonds may preferably comprise low acyl gellan.

The gel composition may contain a gelling agent providing crosslinking through ionic bonds in a range from about 0.3 percent by weight to about 5 percent by weight. Preferably, the composition contains a gelling agent providing crosslinking through ionic bonds in a range from about 0.5 percent by weight to about 3 percent by weight. Preferably, the composition contains a gelling agent providing crosslinking through ionic bonds in a range from about 1 percent by weight to about 2 percent by weight.

The gel composition may comprise gellan with a low acyl content in the range of about 0.2 percent by weight to about 5 percent by weight. Preferably, the gellan with a low acyl content may be in the range of about 0.5 percent by weight to about 3 percent by weight. Preferably, the gellan with a low acyl content may be in the range of about 0.5 percent by weight to about 2 percent by weight. Preferably, the gellan with a low acyl content may be in the range of about 1 percent by weight to about 2 percent by weight.

The gel composition may contain pectin in a range of from about 0.2 percent by weight to about 5 percent by weight. Preferably, the pectin may be in a range of from about 0.5 percent by weight to about 3 percent by weight. Preferably, the pectin may be in a range of from about 0.5 percent by weight to about 2 percent by weight. Preferably, the pectin may be in a range of from about 1 percent by weight to about 2 percent by weight.

The gel composition may contain kappa carrageenan in a range of from about 0.2 percent by weight to about 5 percent by weight. Preferably, kappa carrageenan may be in a range of from about 0.5 percent by weight to about 3 percent by weight. Preferably, kappa carrageenan may be in a range of from about 0.5 percent by weight to about 2 percent by weight. Preferably, kappa carrageenan may be in a range of from about 1 percent by weight to about 2 percent by weight.

The gel composition may contain iota-carrageenan in a range of from about 0.2 percent by weight to about 5 percent by weight. Preferably, iota-carrageenan may be in a range of from about 0.5 percent by weight to about 3 percent by weight. Preferably, iota-carrageenan may be in a range of from about 0.5 percent by weight to about 2 percent by weight. Preferably, iota-carrageenan may be in a range of from about 1 percent by weight to about 2 percent by weight.

The gel composition may contain alginate in a range from about 0.2 percent by weight to about 5 percent by weight. Preferably, the alginate may be in a range from about 0.5 percent by weight to about 3 percent by weight. Preferably, the alginate may be in a range from about 0.5 percent by weight to about 2 percent by weight. Preferably, the alginate may be in a range from about 1 percent by weight to about 2 percent by weight.

The gel composition may comprise a gelling agent providing crosslinking by means of hydrogen bonds and a gelling agent providing crosslinking by means of ionic bonds in a ratio of about 3:1 to about 1:3. Preferably, the gel composition may comprise a gelling agent providing crosslinking by means of hydrogen bonds and a gelling agent providing crosslinking by means of ionic bonds in a ratio of about 2:1 to about 1:2. Preferably, the gel composition may comprise a gelling agent providing crosslinking by means of hydrogen bonds and a gelling agent providing crosslinking by means of ionic bonds in a ratio of about 1:1.

The gel composition may further comprise a viscosity increasing agent. The viscosity increasing agent in combination with a gelling agent providing crosslinking by hydrogen bonds and a gelling agent providing crosslinking by ionic bonds appears to unexpectedly maintain a solid environment and preserve the gel composition, even if the gel composition contains a high level of glycerol.

The term "viscosity increasing agent" refers to a compound which, when uniformly added to a 50 percent by weight water/50 percent by weight glycerol mixture at 25 °C in an amount of 0.3 percent by weight, increases the viscosity without causing gel formation, while the mixture remains or remains liquid. Preferably, the viscosity increasing agent refers to a compound which, when uniformly added to a 50 percent by weight water/50 percent by weight glycerol mixture at 25 °C in an amount of 0.3 percent by weight, increases the viscosity to at least 50 cP, preferably at least 200 cP, preferably at least 500 cP, preferably at least 1000 cP at a shear rate of 0.1 s ^-1 , without causing gel formation, while the mixture remains or remains liquid. Preferably, the viscosity increasing agent refers to a compound which, when uniformly added to a 50 percent by weight water/50 percent by weight glycerol mixture at 25 °C in an amount of 0.3 percent by weight, increases the viscosity by at least 2 times, or at least 5 times, or at least 10 times, or at least 100 times than before addition, at a shear rate of 0.1 s ^-1 , without causing gel formation, while the mixture remains or remains liquid.

The viscosity values given in this document can be measured using a Brookfield RVT viscometer rotating an RV#2 disc type shaft at 25°C at 6 revolutions per minute (rpm).

The gel composition preferably comprises a viscosity increasing agent in the range of about 0.2 percent by weight to about 5 percent by weight. Preferably, the composition comprises a viscosity increasing agent in the range of about 0.5 percent by weight to about 3 percent by weight. Preferably, the composition comprises a viscosity increasing agent in the range of about 0.5 percent by weight to about 2 percent by weight. Preferably, the composition comprises a viscosity increasing agent in the range of about 1 percent by weight to about 2 percent by weight.

The viscosity increasing agent may comprise one or more of xanthan gum, carboxymethyl cellulose, microcrystalline cellulose, methyl cellulose, acacia, guar gum, lambda carrageenan or starch. The viscosity increasing agent may preferably comprise xanthan gum.

The gel composition may contain xanthan gum in a range of from about 0.2 percent by weight to about 5 percent by weight. Preferably, the xanthan gum may be in a range of from about 0.5 percent by weight to about 3 percent by weight. Preferably, the xanthan gum may be in a range of from about 0.5 percent by weight to about 2 percent by weight. Preferably, the xanthan gum may be in a range of from about 1 percent by weight to about 2 percent by weight.

The gel composition may contain carboxymethylcellulose in a range of from about 0.2 percent by weight to about 5 percent by weight. Preferably, the carboxymethylcellulose may be in a range of from about 0.5 percent by weight to about 3 percent by weight. Preferably, the carboxymethylcellulose may be in a range of from about 0.5 percent by weight to about 2 percent by weight. Preferably, the carboxymethylcellulose may be in a range of from about 1 percent by weight to about 2 percent by weight.

The gel composition may contain microcrystalline cellulose in a range from about 0.2 percent by weight to about 5 percent by weight. Preferably, the microcrystalline cellulose may be in a range from about 0.5 percent by weight to about 3 percent by weight. Preferably, the microcrystalline cellulose may be in a range from about 0.5 percent by weight to about 2 percent by weight. Preferably, the microcrystalline cellulose may be in a range from about 1 percent by weight to about 2 percent by weight.

The gel composition may contain methylcellulose in a range of from about 0.2 percent by weight to about 5 percent by weight. Preferably, the methylcellulose may be in a range of from about 0.5 percent by weight to about 3 percent by weight. Preferably, the methylcellulose may be in a range of from about 0.5 percent by weight to about 2 percent by weight. Preferably, the methylcellulose may be in a range of from about 1 percent by weight to about 2 percent by weight.

The gel composition may contain acacia in a range of about 0.2 percent by weight to about 5 percent by weight. Preferably, the acacia may be in a range of about 0.5 percent by weight to about 3 percent by weight. Preferably, the acacia may be in a range of about 0.5 percent by weight to about 2 percent by weight. Preferably, the acacia may be in a range of about 1 percent by weight to about 2 percent by weight.

The gel composition may contain guar gum in a range from about 0.2 percent by weight to about 5 percent by weight. Preferably, guar gum may be in a range from about 0.5 percent by weight to about 3 percent by weight. Preferably, guar gum may be in a range from about 0.5 percent by weight to about 2 percent by weight. Preferably, guar gum may be in a range from about 1 percent by weight to about 2 percent by weight.

The gel composition may contain lambda carrageenan in a range of from about 0.2 percent by weight to about 5 percent by weight. Preferably, lambda carrageenan may be in a range of from about 0.5 percent by weight to about 3 percent by weight. Preferably, lambda carrageenan may be in a range of from about 0.5 percent by weight to about 2 percent by weight. Preferably, lambda carrageenan may be in a range of from about 1 percent by weight to about 2 percent by weight.

The gel composition may contain starch in a range from about 0.2 percent by weight to about 5 percent by weight. Preferably, the starch may be in a range from about 0.5 percent by weight to about 3 percent by weight. Preferably, the starch may be in a range from about 0.5 percent by weight to about 2 percent by weight. Preferably, the starch may be in a range from about 1 percent by weight to about 2 percent by weight.

The gel composition may further comprise a divalent cation. Preferably, the divalent cation comprises calcium ions, such as calcium lactate in solution. Divalent cations (such as calcium ions) may promote gelling of compositions that contain gelling agents, such as, for example, a gelling agent that provides crosslinking through ionic bonds. The ionic effect may promote gelling. The divalent cation may be present in the gel composition in a range of from about 0.1 to about 1 percent by weight, or in an amount of about 0.5 percent by weight to about 1 percent by weight.

The gel composition may further comprise an acid. The acid may comprise a carboxylic acid. The carboxylic acid may comprise a ketone group. Preferably, the carboxylic acid may comprise a ketone group having less than about 10 carbon atoms, or less than about 6 carbon atoms, or less than about 4 carbon atoms, such as levulinic acid or lactic acid. Preferably, this carboxylic acid has three carbon atoms (e.g., lactic acid). Lactic acid unexpectedly improves the stability of the gel composition even compared to similar carboxylic acids. The carboxylic acid may promote gelation. The carboxylic acid may reduce the change in the concentration of the alkaloid compound, or the concentration of the cannabinoid compound, or the concentration of both the alkaloid compound and the cannabinoid compound within the gel composition during storage. The carboxylic acid may reduce the change in the concentration of nicotine within the gel composition during storage.

The gel composition may contain a carboxylic acid in a range from about 0.1 percent by weight to about 5 percent by weight. Preferably, the carboxylic acid may be in a range from about 0.5 percent by weight to about 3 percent by weight. Preferably, the carboxylic acid may be in a range from about 0.5 percent by weight to about 2 percent by weight. Preferably, the carboxylic acid may be in a range from about 1 percent by weight to about 2 percent by weight.

The gel composition may contain lactic acid in a range from about 0.1 percent by weight to about 5 percent by weight. Preferably, the lactic acid may be in a range from about 0.5 percent by weight to about 3 percent by weight. Preferably, the lactic acid may be in a range from about 0.5 percent by weight to about 2 percent by weight. Preferably, the lactic acid may be in a range from about 1 percent by weight to about 2 percent by weight.

The gel composition may contain levulinic acid in a range of from about 0.1 percent by weight to about 5 percent by weight. Preferably, levulinic acid may be in a range of from about 0.5 percent by weight to about 3 percent by weight. Preferably, levulinic acid may be in a range of from about 0.5 percent by weight to about 2 percent by weight. Preferably, levulinic acid may be in a range of from about 1 percent by weight to about 2 percent by weight.

The gel composition preferably contains some water. The gel composition is more stable if the composition contains some water. Preferably, the gel composition contains at least about 1 percent by weight, or at least about 2 percent by weight, or at least about 5 percent by weight of water. Preferably, the gel composition contains at least about 10 percent by weight, or at least about 15 percent by weight of water.

Preferably, the gel composition comprises from about 8 percent by weight to about 32 percent by weight of water. Preferably, the gel composition comprises from about 15 percent by weight to about 25 percent by weight of water. Preferably, the gel composition comprises from about 18 percent by weight to about 22 percent by weight of water. Preferably, the gel composition comprises about 20 percent by weight of water.

Preferably, the aerosol generating substrate comprises from about 150 mg to about 350 mg of the gel composition.

Preferably, in embodiments comprising a gel composition, the aerosol generating substrate comprises a porous medium filled with a gel composition. The advantages of a porous medium filled with a gel composition are that the gel composition is retained within the porous medium, and this can facilitate the manufacture, storage or transportation of the gel composition. This can help maintain the desired shape of the gel composition, especially during manufacture, transportation or use.

The term "porous" is used herein to refer to a material that has multiple pores or openings in it that allow air to pass through the material.

The porous medium may be any suitable porous material capable of holding or retaining the gel composition. Ideally, the porous medium may allow the gel composition to move within it. In particular embodiments, the porous medium comprises natural materials, synthetic or semi-synthetic materials, or a combination thereof. In particular embodiments, the porous medium comprises a sheet material, a foam material, or fibers, such as loose fibers, or a combination thereof. In particular embodiments, the porous medium comprises a woven, non-woven or extruded material, or combinations thereof. Preferably, the porous medium comprises cotton, paper, viscose, PLA, or cellulose acetate, or combinations thereof. Preferably, the porous medium comprises a sheet material, such as cotton or cellulose acetate. In a particularly preferred embodiment, the porous medium comprises a sheet made of cotton fibers.

The porous medium used in the present invention may be corrugated or split. In preferred embodiments, the porous medium is corrugated. In alternative embodiments, the porous medium comprises a split porous medium. The corrugation or splitting process may be performed before or after filling with the gel composition.

Corrugation of the sheet material has the advantage of improving the structure to provide passages through the structure. The passages through the corrugated sheet material assist in filling the gel, retaining the gel, and also for the fluid to pass through the corrugated sheet material. Therefore, there are advantages to using the corrugated sheet material as a porous medium.

The splitting provides a high surface area to volume ratio for the medium, which is thus able to easily absorb the gel.

In particular embodiments, the sheet material is a composite material. Preferably, the sheet material is porous. The sheet material can facilitate the production of a tubular element containing a gel. The sheet material can facilitate the introduction of an active substance into the tubular element containing a gel. The sheet material can help stabilize the structure of the tubular element containing a gel. The sheet material can facilitate the transportation or storage of the gel. The use of the sheet material allows or provides the addition of structure to a porous medium, for example by corrugating the sheet material.

The porous medium may be a thread. The thread may contain, for example, cotton, paper or acetate rod. The thread may also be filled with a gel, like any other porous medium. The advantage of using a thread as a porous medium is that it can facilitate easy fabrication.

The thread may be filled with gel by any known means. The thread may simply be coated with gel, or the thread may be impregnated with gel. During manufacture, the threads may be impregnated with gel and stored ready for use in the assembly of a tubular element.

The porous medium filled with the gel composition is preferably provided inside a tubular element that forms part of the aerosol-generating article. Ideally, the tubular element may be longer in longitudinal length than in width, but not necessarily, since it may be one part of a multi-component element that will ideally be longer in its longitudinal length than in its width. Typically, the tubular element is cylindrical, but not necessarily. For example, the tubular element may have an oval, polygonal, such as triangular or rectangular, or arbitrary cross-section.

The tubular element preferably comprises a first longitudinal passage. The tubular element is preferably formed from a wrapper that defines the first longitudinal passage. The wrapper is preferably a water-resistant wrapper. This property of water resistance of the wrapper can be achieved by using a water-resistant material or by treating the material of the wrapper. This can be achieved by treating one side or both sides of the wrapper. Having water resistance will help not to lose structure, strength or rigidity. It can also help to prevent leakage of the gel or liquid, especially when using gels of a flowable structure.

Preferably, the plug made of a porous medium filled with a gel composition is surrounded by a water-repellent wrapper.

In some preferred embodiments of the present invention, the elongated current collecting element is positioned substantially longitudinally within the rod of the aerosol generating substrate and is in thermal contact with the aerosol generating substrate.

In the context of this document, in relation to the present invention, the term "current collecting element" refers to a material that can convert electromagnetic energy into heat. When placed within a fluctuating electromagnetic field, eddy currents induced in the current collecting element cause the current collecting element to heat up. Since the elongated current collecting element is placed in thermal contact with the aerosol-generating substrate, the aerosol-generating substrate is heated by the current collecting element.

When used to describe a current collecting element, the term "elongated" means that the current collecting element 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 collecting element is arranged substantially longitudinally within the rod. This means that the length dimension of the elongated current collecting element is arranged approximately parallel to the longitudinal direction of the rod, for example in the range of plus or minus 10 degrees parallel to the longitudinal direction of the rod. In preferred embodiments, the elongated current collecting element can be arranged in a radially central position within the rod and extends along the longitudinal axis of the rod.

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

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

The current collecting element preferably has a length of from about 5 millimeters to about 15 millimeters, for example 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 collecting 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 current collecting 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 current collecting 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 susceptor 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 susceptor 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 susceptor 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 current collecting element and the total length of the substrate of the aerosol generating article is approximately 0.27.

The current collecting element preferably has a width of from approximately 1 millimeter to approximately 5 millimeters.

The current collecting element may substantially have a thickness of about 0.01 millimeters to about 2 millimeters, such as about 0.5 millimeters to about 2 millimeters. In some embodiments, the current collecting element preferably has a thickness of about 10 micrometers to about 500 micrometers, more preferably about 10 micrometers to about 100 micrometers.

If the current collecting element has a constant cross-section, for example a circular cross-section, it has a preferred width or diameter of from approximately 1 millimeter to approximately 5 millimeters.

If the current collecting element has the form of a strip or plate, the strip or plate preferably has a rectangular shape with a width of preferably from about 2 millimeters to about 8 millimeters, more preferably from about 3 millimeters to about 5 millimeters. As an example, the current collecting element in the form of a strip or plate can have a width of about 4 millimeters.

If the current collecting element has the form of a strip or plate, the strip or plate preferably has a rectangular shape and a thickness of about 0.03 millimeters to about 0.15 millimeters, more preferably from about 0.05 millimeters to about 0.09 millimeters. As an example, the current collecting element in the form of a strip or plate can have a thickness of about 0.07 millimeters.

In a preferred embodiment, the elongated current collecting element in the form of a strip or plate is preferably rectangular in shape and has a thickness of from about 55 micrometers to about 65 micrometers.

More preferably, the elongated current collecting element has a thickness of about 57 micrometers to about 63 micrometers. Even more preferably, the elongated current collecting element has a thickness of about 58 micrometers to about 62 micrometers. In a particularly preferred embodiment, the elongated current collecting element has a thickness of about 60 micrometers.

Preferably, the elongated current-collecting element has a length that is equal to or less than the length of the aerosol-generating substrate. Preferably, the elongated current-collecting element has the same length as the aerosol-generating substrate.

The current collecting element may be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from an aerosol generating substrate. Preferred current collecting elements comprise metal or carbon.

A preferred current collector may comprise or consist of a ferromagnetic material, such as a ferromagnetic alloy, ferritic iron, or ferromagnetic steel, or stainless steel. A suitable current collector may be made of or comprise aluminum. Preferred current collectors may be made of 400 series stainless steel, such as grade 410 stainless steel, or grade 420 stainless steel, or grade 430 stainless steel. Different materials will dissipate different amounts of energy when they are located within electromagnetic fields having similar frequency and field strength values.

Thus, the parameters of the current collecting element, such as the type of material, length, width and thickness, can be changed to provide the desired power dissipation within a known electromagnetic field. Preferred current collecting elements can be heated to temperatures in excess of 250 degrees Celsius.

Suitable current-collecting elements may comprise a non-metallic core with a metal layer located on the non-metallic core, for example with metal tracks formed on the surface of a ceramic core. The current-collecting element may have a protective outer layer, for example a protective ceramic layer or a protective glass layer, covering the current-collecting element. The current-collecting element may comprise a protective coating made of glass, ceramic or inert metal, which is formed over the core material of the current-collecting element.

The current collector element is arranged in thermal contact with the aerosol-generating substrate. Thus, when the current collector element is heated, the aerosol-generating substrate is heated and an aerosol is formed. Preferably, the current collector element is arranged in direct physical contact with the aerosol-generating substrate, for example, inside the aerosol-generating substrate.

The current collecting element may be a current collecting element consisting of several materials, and may comprise a first current collecting element material and a second current collecting element material. The first current collecting element material is arranged in direct physical contact with the second current collecting element material. The second current collecting element material preferably has a Curie temperature that is lower than 500 degrees Celsius. The first current collecting element material is preferably used mainly for heating the current collecting element when the current collecting element is placed in a fluctuating electromagnetic field. Any suitable material may be used. For example, the first current collecting element material may be aluminum or may be a ferrous metal such as stainless steel. The second current collecting element material is preferably used mainly for indicating that the current collecting material has reached a specific temperature, wherein this temperature is the Curie temperature of the second current collecting element material. The Curie temperature of the second current-collecting element material can be used to control the temperature of the entire current-collecting element during operation. Thus, the Curie temperature of the second current-collecting element material should be below the ignition point of the aerosol-generating substrate. Suitable materials for the second current-collecting element material may include nickel and certain nickel alloys.

By providing a current-receiving element having at least a first and a second current-receiving element material, wherein either the second current-receiving element material has a Curie temperature and the first current-receiving element material does not have a Curie temperature, or the first and second current-receiving element materials have a first and a second Curie temperature different from each other, it is possible to separate the heating of the aerosol-generating substrate and to regulate the heating temperature. The first current-receiving element material is preferably a magnetic material having a Curie temperature that is higher than 500 degrees Celsius. From the viewpoint of heating efficiency, it is desirable that the Curie temperature of the first current-receiving element material exceeds any maximum temperature to which the current-receiving element should be able to be heated. The second Curie temperature can be preferably selected so as to be lower than 400 degrees Celsius, preferably lower than 380 degrees Celsius or lower than 360 degrees Celsius. Preferably, the second material of the current-receiving element is a magnetic material selected in such a way that it has a second Curie temperature that substantially coincides with the required maximum heating temperature. That is, it is preferable that the second Curie temperature is approximately the same as the temperature to which the current-receiving element must be heated in order to generate an aerosol from the aerosol-generating substrate. The second Curie temperature can, for example, be within the range from 200 degrees Celsius to 400 degrees Celsius or from 250 degrees Celsius to 360 degrees Celsius. The second Curie temperature of the second material of the current-receiving element can, for example, be selected such that, when heated by the current-receiving element, which is at a temperature equal to the second Curie temperature, the total average temperature of the aerosol-generating substrate does not exceed 240 degrees Celsius.

The aerosol generating articles according to the present invention may further comprise an upstream element arranged upstream and adjacent to the aerosol generating substrate, wherein the aerosol generating 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 may prevent direct physical contact with the upstream end of the susceptor element. This helps to prevent displacement or deformation of the susceptor element during processing or transportation of the aerosol generating article. This, in turn, helps to maintain the shape and position of the susceptor element. In addition, the presence of the upstream element helps to prevent any loss of the substrate.

The upstream element may also advantageously compensate for any potential reduction in RTD, such as due to evaporation of the gel composition when the aerosol generating substrate rod is heated during use.

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

The upstream element may be a porous element in the form of a plug. Preferably, the porous element in the form of a plug does not change the resistance to draw of the aerosol-generating article. Preferably, the upstream element has a porosity of at least about 50 percent in the longitudinal direction of the aerosol-generating article. More preferably, the upstream element has a porosity of from about 50 percent to about 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 in the position of the upstream element.

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

The porosity or permeability of the upstream element can advantageously be varied to provide a 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 column. More preferably, the RTD of the upstream element is less than or equal to about 60 millimeters of water column. Even more preferably, the RTD of the upstream element is less than or equal to about 40 millimeters of water column.

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.

Preferably, the RTD of the upstream element is greater than the RTD of the mouthpiece element. Preferably, the RTD of the upstream element is at least 1.5 times the RTD of the mouthpiece element, more preferably at least 2 times the RTD of the mouthpiece element, and more preferably at least 2.5 times the RTD of the mouthpiece element. This advantageously provides a greater proportion of the total RTD of the aerosol-generating article upstream of the aerosol-generating substrate rod. This allows the RTD of the mouthpiece element to be minimized, so that the effect of filtration on the aerosol can also be minimized if desired.

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 ventilation 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 as is 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, a polymeric material, cellulose acetate, cardboard, zeolite, or an aerosol-generating substrate. Preferably, the upstream element is formed from a cellulose acetate plug.

Preferably, the upstream element is formed from a heat-resistant material. For example, the upstream element is preferably formed from a material that can withstand temperatures of up to 350 degrees Celsius. This ensures that the upstream element is not adversely affected by the heating means for heating the aerosol-generating 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 about 1 millimeter to about 10 millimeters, more preferably about 3 millimeters to about 8 millimeters, more preferably 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, level surface over 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 according to the present invention may have a length from about 35 millimeters to about 100 millimeters.

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

The total length of the aerosol-generating article according to the present invention is preferably less than or equal to 70 millimeters. More preferably, the total length of the aerosol-generating article according to the present invention is preferably less than or equal to 60 millimeters. Even more preferably, the total 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 preferably 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 that is less than or equal to approximately 12 millimeters. More preferably, the aerosol-generating article has an outer diameter that is less than or equal to approximately 10 millimeters. Even more preferably, the aerosol-generating article has an outer diameter that is 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 mouth 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 mouth 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.

As an example, the outer diameter of the article may be substantially constant on a distal portion of the article extending from the distal end of the aerosol-generating article by at least about 5 millimeters or at least about 10 millimeters. Alternatively, the outer diameter of the article may taper on a distal portion of the article extending from the distal end by at least about 5 millimeters or at least about 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.

Providing an arrangement of the elements such that the center of mass is closer to the upstream end than to the downstream end causes the aerosol generating article to have a weight imbalance with the heavier upstream end. This weight imbalance can advantageously provide tactile feedback to the consumer so that he or she can differentiate 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 article are visually similar to each other.

In embodiments of the 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 anything further downstream, such as the mouthpiece element.

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, there may be difficulties in processing individual elements that are shorter in length than their diameter. For example, for elements with a diameter of 7 millimeters, a length of approximately 7 millimeters represents a threshold value that it 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 generating substrate rod, etc.) to produce a hollow segment of 24 millimeters, which is then cut into two intermediate hollow sections of 12 millimeters.

In particularly preferred embodiments, the other components of the aerosol-generating article are individually surrounded by their own wrapper. In other words, each of the upstream element, the aerosol-generating substrate rod, the support element, and the aerosol-cooling element is 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-generating substrate rod, and the intermediate hollow section are then combined together 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 commonly used method of determining this property is by measuring the water contact angle. "Water contact angle" is the angle, typically measured by a liquid, where the liquid/vapor interface meets a solid surface. In quantitative terms, it indicates 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.

As an 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 have a surface treatment that includes 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 generating substrate rod positioned immediately downstream of the upstream element, a support element positioned immediately downstream of the aerosol generating 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 generating substrate rod may be adjacent to the upstream element. The support element may be adjacent to the aerosol generating 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 upstream element has a length of approximately 5 millimeters, the rod of the aerosol-generating article has a length of approximately 12 millimeters, the support element has a length of approximately 8 millimeters, the mouthpiece element has a length of approximately 12 millimeters. Thus, the total length of the aerosol-generating article is approximately 45 millimeters.

The upstream element is in the form of a cellulose acetate plug that is wrapped in a rigid wrapper.

An aerosol-generating article comprises an elongated current-receiving element arranged substantially longitudinally inside the rod of the aerosol-generating substrate and is in thermal contact with the aerosol-generating substrate. The current-receiving element has the form of a strip or plate, has a length substantially equal to the length of the rod of the aerosol-generating substrate, and a thickness of approximately 60 micrometers.

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

The aerosol cooling element is in the form of a thinner hollow cellulose acetate tube and has an internal diameter of approximately 3.25 millimeters. Thus, the thickness of the peripheral wall 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 generating substrate rod comprises an aerosol generating substrate comprising a gel composition.

The present invention will now be further described with reference to the accompanying drawings in Fig. 1, which shows a schematic side sectional view of an aerosol generating article according to the present invention.

The aerosol generating article 10 shown in Fig. 1 comprises a rod 12 of an aerosol generating substrate 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 mouth end 20.

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

The downstream section 14 comprises a support element 22 positioned immediately downstream of the aerosol-generating substrate rod 12, wherein the support element 22 is in longitudinal alignment with the rod 12. In the embodiment of Fig. 1, the upstream end of the support element 22 is adjacent to the downstream end of the aerosol-generating substrate rod 12. The downstream section 14 further comprises an aerosol cooling element 24 positioned immediately downstream of the support element 22, wherein the aerosol cooling element 24 is in longitudinal alignment with the rod 12 and the support element 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 element 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 50 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 26. The internal cavity 28 is substantially empty, and therefore a substantially unrestricted flow of air 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 provided in the form of a hollow cylindrical tube formed from 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 flow of air along the internal cavity 36 is possible. The second hollow tubular segment 34 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 38 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 24.

The mouthpiece element 42 is provided in the form of a cylindrical plug 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.

The rod 12 comprises an aerosol generating substrate comprising a porous medium filled with a gel composition as defined above. An example of a suitable gel composition is shown below in Table 1:

Table 1: Gel composition

Component Quantity (% by weight) Water 20 Glycerol 73.5 Nicotine 1.5 Gelling agent 3 Lactic acid 1 Divalent cations 1

The rod 12 of the aerosol generating substrate 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-collecting element 44 inside the rod 12 of the aerosol-generating substrate. In more detail, the current-collecting element 44 is arranged substantially longitudinally inside the aerosol-generating substrate so as to be approximately parallel to the longitudinal direction of the rod 12. As shown in the image of Fig. 1, the current-collecting element 44 is arranged in a radially central position inside the rod and extends substantially along the longitudinal axis of the rod 12.

The current collecting element 44 extends the entire distance from the upstream end to the downstream end of the rod 12. In fact, the current collecting element 44 has substantially the same length as the rod 12 of the aerosol generating substrate.

In the embodiment of Fig. 1, the current collecting element 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, which is positioned immediately upstream of the rod 12 of the aerosol generating 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 generating substrate. This advantageously prevents the current collecting element 44 from shifting. In addition, this ensures that the consumer cannot accidentally touch the heated current collecting element 44 after use.

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

Claims (19)

1. An aerosol-generating article for producing an inhalable aerosol upon heating, wherein the aerosol-generating article comprises: an aerosol generating substrate rod comprising a gel composition, wherein the gel composition comprises at least one gelling agent, at least one of an alkaloid compound and a cannabinoid compound, and an aerosol forming agent; mouthpiece element; and an intermediate hollow section between the aerosol generating substrate rod and the mouthpiece element, wherein the intermediate hollow section comprises: a support element located downstream of the aerosol generating substrate rod, wherein the support element comprises a first hollow tubular segment defining a longitudinal cavity providing a channel for unrestricted flow, and the first hollow tubular segment has a wall thickness of at least 1 millimeter; and an aerosol cooling element located in axial alignment with the mouthpiece element and adjacent to an upstream end of the mouthpiece element, wherein the aerosol cooling element comprises a second hollow tubular segment having a length of less than 10 millimeters, and the second hollow tubular segment forms a longitudinal cavity providing a channel for unrestricted flow, wherein the flow channel is empty. 2. An aerosol-generating article according to claim 1, wherein the rod of the aerosol-generating substrate comprises a plug made of a porous medium filled with a gel composition. 3. An aerosol-generating article according to claim 2, wherein the porous medium is made in the form of a corrugated sheet. 4. An aerosol generating article according to claim 2 or 3, wherein the porous medium comprises cotton fibers. 5. An aerosol generating article according to any one of claims 2 to 4, wherein the plug made of a porous medium filled with a gel composition is surrounded by a water-repellent wrapper. 6. An aerosol-generating article according to any preceding claim, wherein the gel composition comprises at least 1 percent by weight nicotine. 7. An aerosol generating article according to any preceding claim, wherein the gel composition further comprises an acid. 8. An aerosol-generating article according to any preceding claim, wherein the gel composition comprises from 1 to 6 percent by weight of at least one gelling agent. 9. An aerosol generating article according to any preceding claim, which further comprises an elongated current collecting element extending longitudinally through the rod of the aerosol generating substrate. 10. An aerosol-generating article according to any preceding claim, wherein the length of the mouthpiece element is at least 10 millimetres. 11. An aerosol generating article according to any preceding claim, wherein the length of the mouthpiece element is at least 2 millimetres longer than the length of the aerosol cooling element. 12. An aerosol generating article according to any preceding claim, wherein the hollow tubular segment of the aerosol cooling element has a wall thickness of less than 2.5 millimetres. 13. An aerosol generating article according to any preceding claim, wherein the mouthpiece element comprises a mouthpiece filter segment formed from a fibrous filter material, wherein the mouthpiece filter segment has a length of at least 10 millimetres. 14. An aerosol generating article according to any preceding claim, which further comprises an upstream element located upstream of the aerosol generating substrate rod.

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