ES3008185T3 - Aerosol-generating article including substrate with gel composition - Google Patents

Abstract

An aerosol-generating article (10) is provided for producing an inhalable aerosol by heating. The article (10) comprises: an aerosol-generating substrate rod (12) comprising a gel composition, which gel composition comprises at least one gelling agent, at least one alkaloid compound, a cannabinoid compound, and an aerosol former; a mouthpiece (42); and an intermediate hollow section (50) between the aerosol-generating substrate rod and the mouthpiece. The intermediate hollow section (50) comprises an aerosol cooling element (24) axially aligned with and abutting the upstream end thereof (42). The aerosol cooling element (24) comprises a hollow tubular segment (34) having a length of less than 10 millimeters and defining a longitudinal cavity providing an unrestricted flow channel, the flow channel being substantially empty. The intermediate hollow section (50) further comprises a support element (22) downstream of the aerosol-generating substrate rod (12), the support element comprising a hollow tubular segment (26) defining a longitudinal cavity (28) providing an unrestricted flow channel, the hollow tubular segment (26) having a wall thickness of at least 1 millimeter. (Automatic translation with Google Translate, no legal value)

Description

DESCRIPTION

Aerosol-generating article that includes a substrate with a gel composition

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

A number of prior art documents describe aerosol-generating devices for consumer aerosol-generating articles. Such devices include, for example, electrically heated aerosol-generating devices in which an aerosol is generated by the transfer of heat from one or more electrical heating elements of the aerosol-generating device to the aerosol-generating substrate of a heated aerosol-generating article. For example, electrically heated aerosol-generating devices comprising an internal heating sheet adapted to be inserted into the aerosol-generating substrate have been proposed. Alternatively, induction-heatable aerosol-generating articles comprising an aerosol-generating substrate and a susceptor element disposed within the aerosol-generating substrate have been proposed by WO 2015/176898.

US 2014/305448 A1 describes an aerosol-generating article comprising: an aerosol-forming substrate, a support element located downstream of the aerosol-forming substrate, an aerosol-cooling element located downstream of the support element, and an outer envelope circumscribing the aerosol-forming substrate, the support element, and the aerosol-cooling element. The aerosol-generating article may comprise a nozzle located at the downstream end of the aerosol-generating article. The aerosol-forming substrate may be a solid aerosol-forming substrate deposited on the surface of a carrier in the form of, for example, a sheet, foam, gel, or slurry. The support element may comprise a hollow tubular element. The aerosol-cooling element may comprise a plurality of longitudinally extending channels defined by a sheet that has been one or more of creased, pleated, gathered, and folded to form the channels.

Aerosol-generating articles in which a tobacco-containing substrate is heated rather than burned present several challenges not encountered with conventional smoking articles. First, tobacco-containing substrates are typically heated to significantly lower temperatures compared to the temperatures reached by the combustion front in a conventional cigarette. This can impact the release of nicotine from the tobacco-containing substrate and the delivery of nicotine to the consumer. At the same time, if the heating temperature is increased in an attempt to increase nicotine delivery, then the generated aerosol typically needs to be cooled to a greater extent and more rapidly before it reaches the consumer. However, technical solutions that were commonly used to cool mainstream smoke in conventional smoking articles, such as the provision of a high-filtration efficiency segment at the mouth-side end of a cigarette, may have undesirable effects in an aerosol-generating article in which a tobacco-containing substrate is heated rather than burned, as they can reduce nicotine delivery. Secondly, there is a general need for aerosol-generating devices that are easy to use and have improved practicality.

Therefore, it would be desirable to provide a new and improved aerosol-generating article that is adapted to achieve at least one of the desirable results described above. Furthermore, it would be desirable to provide such an aerosol-generating article that can be manufactured efficiently and at high speed, preferably with a satisfactory RTD and low variability from one article to another.

In accordance with the invention there is provided an aerosol-generating article for producing an inhalable aerosol upon heating, the aerosol-generating article comprising: an aerosol-generating substrate rod comprising a gel composition, the gel composition comprising at least one gelling agent, at least one of an alkaloid compound and a cannabinoid compound, and an aerosol former; a mouthpiece member; and a hollow section intermediate between the aerosol-generating substrate rod and the mouthpiece member. The hollow section intermediate comprises: a support member downstream of the aerosol-generating substrate rod, the support member comprising a first hollow tubular segment defining a longitudinal cavity providing an unrestricted flow channel, the first hollow tubular segment having a wall thickness of at least 1 millimeter; and an aerosol cooling element in axial alignment with the nozzle element and abutting the upstream end of the nozzle element, the aerosol cooling element comprising a second hollow tubular segment having a length of less than 10 millimeters and an internal diameter of at least 2 millimeters, the second hollow tubular segment defining a longitudinal cavity providing an unrestricted flow channel, wherein the flow channel is void.

The term “aerosol-generating article” is used herein to denote an article wherein an aerosol-generating substrate is heated to produce an inhalable aerosol for a consumer. As used herein, the term “aerosol-generating substrate” denotes a substrate capable of releasing volatile compounds upon heating 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 inhalable smoke. In contrast, in heated aerosol-generating articles, an 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 an aerosol is generated by the transfer of heat from a carburizing fuel element or heat source to a physically separate aerosol-forming material. For example, aerosol-generating articles according to the invention find particular application in aerosol-generating systems comprising an electrically heated aerosol-generating device having an internal heating sheet adapted to be inserted into the aerosol-generating substrate rod. Aerosol-generating articles of this type are described in the prior art.

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

As used herein with reference to the present invention, the term “bar” is used to denote a generally cylindrical element of essentially circular, oval or elliptical cross-section.

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

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

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

As used herein, the term "hollow tubular segment" is used to denote a generally elongated element defining a lumen or airflow passageway along a longitudinal axis thereof. In particular, the term "tubular" will be used below with reference to a tubular element having an essentially cylindrical cross-section and defining at least one airflow conduit establishing continuous, uninterrupted communication between an upstream end of the tubular element and a downstream end of the tubular element. However, it should be understood that geometries (e.g., alternative cross-sectional shapes) of the tubular segment may be possible. The hollow tubular segment is a discrete, individual element of the aerosol-generating article having a defined length and thickness.

As used herein, the term “elongated” means that an element has a length dimension that is greater than its width dimension or its diameter dimension, for example, two or more times its width dimension or its diameter dimension.

In the context of the present invention, a hollow tubular segment provides an unrestricted flow channel. This means that the hollow tubular segment provides a negligible level of aspiration resistance (AR). Therefore, the flow channel should be free of any components that obstruct the airflow in a longitudinal direction. Preferably, the flow channel is substantially empty.

The aerosol-generating article according to the present invention therefore provides a novel configuration of elements, including a combination of an aerosol-generating substrate comprising a gel composition with an aerosol-cooling element formed from a hollow tubular segment having a length of less than 10 millimeters. This combination of elements has been found to achieve optimal aerosol delivery to the consumer during use.

The use of an aerosol-generating substrate formed with a gel composition to form the aerosol upon heating is convenient because it provides a uniform substrate that can generate a highly consistent aerosol.

The aerosol-generating article includes an aerosol cooling element that is less than 10 millimeters long and is therefore relatively short compared to aerosol cooling elements of prior art aerosol-generating articles. This reduction in the length of the aerosol cooling element compared to known aerosol cooling elements is made possible by the construction of the aerosol cooling element in the form of a hollow tubular segment. The hollow tubular segment provides an internal cavity with a relatively high volume, which achieves highly effective cooling and nucleation of the aerosol during use. Sufficient cooling and nucleation of the aerosol can therefore be provided over a relatively short distance, such that the length of the aerosol cooling element can be shorter than has typically been possible with other aerosol cooling element constructions.

Reducing the length of the aerosol cooling element provides several potential technical benefits. The aerosol cooling element typically has a lower resistance to deformation than the nozzle element. Reducing the length of the aerosol cooling element therefore reduces the risk of deformation of the aerosol-generating article due to compression during use. Furthermore, reducing the length of the aerosol cooling element can provide a cost benefit to the manufacturer, since the cost of a hollow tubular segment is typically higher per unit length than the cost of a nozzle element.

Advantageously, the reduction in the length of the aerosol cooling element can be offset by an increase in the length of the nozzle element. It has been found that the combination of a nozzle element of increased length and an aerosol cooling element of reduced length makes it possible to provide a stiffer nozzle element in the aerosol-generating article according to the invention. Therefore, the aerosol-generating article is capable of providing increased resistance to radial compression at a location toward the downstream end of the article. Advantageously, this benefit can be provided without affecting the overall length of the article, such that an overall length consistent with existing aerosol-generating articles can be maintained.

In accordance with the present invention, there is provided an aerosol-generating article for generating an inhalable aerosol upon heating. The aerosol-generating article comprises an aerosol-generating substrate bar. The aerosol-generating article further comprises a downstream section at a location downstream of the aerosol-generating substrate bar. The downstream section comprises one or more downstream elements.

In the aerosol-generating article according to the present invention, the downstream section comprises a nozzle element. The nozzle element may extend to a mouth-side end of the aerosol-generating article. The downstream section further comprises a hollow section intermediate between the nozzle element and the bar 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 comprises a support element, which comprises a hollow tubular segment.

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

The aerosol-generating article may further comprise a section located upstream of the aerosol-generating substrate bar. The upstream section may comprise one or more upstream elements. In some embodiments, the upstream section may comprise an upstream element that is disposed immediately upstream of the aerosol-generating substrate bar.

The aerosol-generating article may further comprise a susceptor element within the aerosol-generating substrate. In some embodiments, the susceptor element may be an elongated susceptor element. In preferred embodiments, the susceptor element extends longitudinally within the aerosol-generating substrate.

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

As defined above, the downstream section of the aerosol-generating article of the present invention comprises a nozzle element. The nozzle element may preferably be located at the downstream or mouth-side end of the aerosol-generating article. The nozzle element preferably comprises at least one nozzle filter segment for filtering aerosol generated from the aerosol-generating substrate. For example, the nozzle element may comprise one or more segments of a fibrous filter material. Suitable fibrous filter materials will be known to those skilled in the art. Particularly preferably, the at least one nozzle filter segment comprises a cellulose acetate filter segment formed from cellulose acetate tow.

In certain preferred embodiments, the nozzle element consists of a single nozzle filter segment. In alternative embodiments, the nozzle element includes two or more nozzle filter segments axially aligned in an end-to-end abutting relationship with one another.

Preferably, the nozzle element comprises a nozzle 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 invention, the downstream section may comprise a mouth-side end cavity at the downstream end, which is located downstream of the nozzle element as described above. The mouth-side end cavity may be defined by a hollow tubular element that is provided at the downstream end of the nozzle. Alternatively, the mouth-side end cavity may be defined by the outer shell of the nozzle element, wherein the outer shell extends in a direction downstream of the nozzle element.

The nozzle element may optionally comprise a flavoring, which may be provided in any suitable form. For example, the nozzle element may comprise one or more capsules, beads, or granules of a flavoring, or one or more flavor-filled threads or filaments.

In an aerosol-generating article according to the present invention the nozzle element forms a part of the downstream section and is therefore located downstream of the aerosol-generating substrate bar.

The nozzle element is preferably located downstream of the aerosol cooling element. Particularly preferably, the nozzle element is located immediately downstream of the aerosol cooling element. For example, the nozzle element may adjoin the downstream end of the aerosol cooling element.

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

Preferably, the nozzle element is circumscribed by a cap envelope. Preferably, the nozzle element is not vented so that air does not enter the aerosol-generating article along the nozzle element.

The nozzle element is preferably connected to one or more of the adjacent upstream components of the aerosol-generating article by means of a tip wrap.

Preferably, the nozzle element has an RTD of less than about 25 millimeters of H2O. More preferably, the nozzle element has an RTD of less than about 20 millimeters of H2O. Even more preferably, the nozzle element has an RTD of less than about 15 millimeters of H2O.

RTD values of about 10 millimeters of H2O to about 15 millimeters of H2O are particularly preferred because a nozzle element having such an RTD is expected to contribute minimally so that the total RTD of the aerosol generating article does not essentially exert a filtering action on the aerosol delivered to the consumer.

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

The nozzle 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 nozzle element preferably has a length of less than about 25 millimeters, more preferably less than about 20 millimeters, most preferably less than about 15 millimeters.

In some preferred embodiments, the nozzle 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 nozzle 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 nozzle 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 nozzle element may have a length between about 5 millimeters and about 25 millimeters, or between about 8 millimeters and about 20 millimeters, or between about 10 millimeters and about 15 millimeters. In a preferred embodiment, the nozzle element has a length of about 12 millimeters.

In certain preferred embodiments of the invention, the nozzle element has a length of at least 10 millimeters. In such embodiments, the nozzle element is therefore relatively long compared to the nozzle element provided in prior art articles. The provision of a relatively long nozzle element in the aerosol-generating articles of the present invention may provide several benefits to the consumer. The nozzle element is typically more resistant to deformation or better adapted to recover its initial shape after deformation than other elements that may be provided downstream of the aerosol-generating substrate bar, such as an aerosol cooling element or support element. Therefore, it is discovered that increasing the length of the nozzle element provides a better grip by the consumer and facilitates insertion of the aerosol-generating article into a heating device. A longer nozzle may additionally be used to provide a higher level of filtration and removal of undesirable aerosol constituents such as phenols, so that a higher quality aerosol can be delivered. Furthermore, the use of a longer nozzle element allows for a more complex nozzle to be provided as there is more room for the incorporation of nozzle components such as capsules, threads and restrictors.

In particularly preferred embodiments of the invention, a mouthpiece element having a length of at least 10 millimeters is combined with the relatively short aerosol cooling element, which has a length of less than 10 millimeters. This combination has been found to provide the aerosol-generating article with a more rigid mouth-side end, which reduces the risk of deformation of the aerosol cooling element during use and contributes to a more efficient puffing action by the consumer.

Preferably, the length of the nozzle element is at least 0.4 times the total length of the intermediate hollow section, preferably at least 0.5 times the length of the intermediate hollow section, more preferably at least 0.6 times the length of the intermediate hollow section, more preferably at least 0.7 times the length of the intermediate hollow section. The ratio of the length of the nozzle element to the total length of the intermediate hollow section is therefore 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.

A ratio between the length of the nozzle element and the length of the aerosol-generating substrate bar may be about 0.5 to about 1.5.

Preferably, a ratio of the length of the nozzle element to the length of the aerosol-generating substrate bar is at least about 0.6, more preferably at least about 0.7, even more preferably at least about 0.8. In preferred embodiments, a ratio of the length of the nozzle element to the length of the aerosol-generating substrate bar is less than about 1.4, more preferably less than about 1.3, even more preferably less than about 1.2.

In some embodiments, a ratio of the length of the nozzle element to the length of the aerosol-generating substrate bar 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, a ratio of the length of the nozzle element to the length of the aerosol-generating substrate bar 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, a ratio of the length of the nozzle element to the length of the aerosol-generating substrate bar 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, a ratio of the length of the nozzle element to the length of the aerosol-generating substrate bar is approximately 1.

A ratio of the length of the nozzle element to the total length of the substrate of the aerosol-generating article may be from about 0.2 to about 0.35.

Preferably, a ratio of the length of the nozzle element to 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. A ratio of the length of the nozzle element to 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, a ratio of the length of the nozzle element to the overall 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, a ratio of the length of the nozzle element to the overall 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, a ratio of the length of the nozzle element to the overall 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, a ratio of the length of the nozzle element to the total length of the substrate of the aerosol-generating article is about 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 disposed in alignment with, and downstream of the bar of the aerosol-generating substrate.

The aerosol cooling element is arranged substantially in alignment with the bar. This means that the longitudinal dimension of the aerosol cooling element is arranged to be approximately parallel to the longitudinal direction of the bar and the article, for example, within plus or minus 10 degrees of parallel to the longitudinal direction of the bar. In preferred embodiments, the aerosol cooling element extends along the longitudinal axis of the bar.

In aerosol-generating articles according to the present invention, the aerosol cooling element is in the form of a hollow tubular segment defining a cavity extending from an upstream end of the aerosol cooling element to a downstream end of the aerosol cooling element. Preferably, a vent zone is provided at a location along the hollow tubular segment.

The inventors have discovered that satisfactory cooling of the aerosol stream generated by heating the aerosol-generating substrate and drawn through one of such aerosol cooling elements is achieved by providing a vent zone at a location along the hollow tubular segment. Furthermore, the inventors have discovered that, as will be described in more detail below, by arranging the vent zone at a precisely defined location along the length of the aerosol cooling element and by preferably utilizing 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 vent air into the article.

Without wishing to be bound by theory, it is hypothesized that because the temperature of the aerosol stream is rapidly reduced by the introduction of vent air as the aerosol travels toward the nozzle segment, the vent air is admitted into the aerosol stream at a location relatively close to the upstream end of the aerosol cooling element (i.e., sufficiently close to the susceptor element extending into the aerosol-generating substrate bar, which is the heat source during use), dramatic cooling of the aerosol stream is achieved, thereby favorably impacting aerosol particle condensation and nucleation. Consequently, the overall ratio of the aerosol particle phase to the aerosol gas phase may be improved as compared to existing non-vented aerosol-generating articles.

At the same time, keeping the peripheral wall thickness of the hollow tubular segment relatively low ensures that the total internal volume of the hollow tubular member - which is made available for the aerosol to begin the nucleation process as soon as the aerosol components leave the aerosol-generating substrate rod - and the cross-sectional surface area of the hollow tubular segment are effectively maximized, while at the same time ensuring that the hollow tubular segment has the necessary structural strength to prevent collapse of the aerosol-generating article, as well as to provide some support to the aerosol-generating substrate rod, and that the RTD of the hollow tubular segment is minimized. It is understood that higher values of the cross-sectional surface area of the cavity of the hollow tubular segment are associated with a reduced velocity of the aerosol stream traveling along the aerosol-generating article, which is also expected to favor aerosol nucleation. Furthermore, it appears that by using a hollow tubular segment with a relatively low thickness, it is possible to essentially prevent diffusion of the ventilation air before it comes into contact with and mixes with the aerosol stream, which is also believed to further favor nucleation phenomena. In practice, by providing more controllable localized cooling of the volatilized species stream, it is possible to enhance the cooling effect on the formation of new aerosol particles.

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 external diameter of between 5 millimeters and 12 millimeters, for example, between 5 millimeters and 10 millimeters, or between 6 millimeters and 8 millimeters. In a preferred embodiment, the aerosol cooling element has an external diameter of 7.2 millimeters plus or minus 10 percent.

The hollow tubular segment of the aerosol cooling element has an internal diameter of at least about 2 millimeters. 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 tube 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, most 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 invention, the aerosol cooling element has a length of less than 10 millimeters. For example, in a particularly preferred embodiment, the aerosol cooling element has a length of 8 millimeters. In such embodiments, the aerosol cooling element therefore has a relatively short length compared to aerosol cooling elements of prior art aerosol-generating articles. A reduction in the length of the aerosol cooling element is possible due to the optimized effectiveness of the hollow tubular segment forming the aerosol cooling element in cooling and nucleating the aerosol. Reducing the length of the aerosol cooling element advantageously reduces the risk of deformation of the aerosol-generating article due to compression during use, since the aerosol cooling element typically has a lower resistance to deformation than the nozzle. Furthermore, reducing the length of the aerosol cooling element can provide an economic benefit to the manufacturer since the cost of a hollow tubular segment is typically higher per unit length than the cost of other elements such as a nozzle element.

A ratio of the length of the aerosol cooling element to the length of the aerosol generating substrate bar may be about 0.25 to about 1.

Preferably, a ratio of the length of the aerosol cooling element to the length of the aerosol generating substrate bar is at least about 0.3, more preferably at least about 0.4, even more preferably at least about 0.5. In preferred embodiments, a ratio of the length of the aerosol cooling element to the length of the aerosol generating substrate bar is less than about 0.9, more preferably less than about 0.8, even more preferably less than about 0.7.

In some embodiments, a ratio of the length of the aerosol cooling element to the length of the aerosol-generating substrate bar 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, a ratio of the length of the aerosol cooling element to the length of the aerosol-generating substrate bar 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, a ratio of the length of the aerosol cooling element to the length of the aerosol-generating substrate bar 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, a ratio of the length of the aerosol cooling element to the length of the aerosol-generating substrate bar is about 0.66.

Preferably, a ratio of the length of the aerosol cooling element to the overall 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. A ratio of the length of the aerosol cooling element to the overall 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, a ratio of the length of the aerosol cooling element to the overall 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, a ratio of the length of the aerosol cooling element to the overall 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, a ratio of the length of the aerosol cooling element to the overall 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, a ratio of the length of the aerosol cooling element to the total length of the substrate of the aerosol generating article is about 0.18.

Preferably, the length of the nozzle element is at least 1 millimeter greater than the length of the aerosol cooling element, more preferably at least 2 millimeters greater than the length of the aerosol cooling element, more preferably at least 3 millimeters greater than the length of the aerosol cooling element. A reduction in the length of the aerosol cooling element, as described above, may advantageously allow an increase in the length of other elements of the aerosol-generating article, such as the nozzle element. The potential technical benefits of providing a relatively long nozzle element are described above.

A ratio of the length of the aerosol cooling element to the length of the aerosol generating substrate bar may be about 0.25 to about 1.

Preferably, a ratio of the length of the aerosol cooling element to the length of the aerosol generating substrate bar is at least about 0.3, more preferably at least about 0.4, even more preferably at least about 0.5. In preferred embodiments, a ratio of the length of the aerosol cooling element to the length of the aerosol generating substrate bar is less than about 0.9, more preferably less than about 0.8, even more preferably less than about 0.7.

In some embodiments, a ratio of the length of the aerosol cooling element to the length of the aerosol-generating substrate bar 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, a ratio of the length of the aerosol cooling element to the length of the aerosol-generating substrate bar 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, a ratio of the length of the aerosol cooling element to the length of the aerosol-generating substrate bar 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, a ratio of the length of the aerosol cooling element to the length of the aerosol-generating substrate bar is about 0.66.

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

Preferably, a ratio of the length of the aerosol cooling element to the overall 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. A ratio of the length of the aerosol cooling element to the overall 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, a ratio of the length of the aerosol cooling element to the overall 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, a ratio of the length of the aerosol cooling element to the overall 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, a ratio of the length of the aerosol cooling element to the overall 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, a ratio of the length of the aerosol cooling element to the total length of the substrate of the aerosol generating article is about 0.18.

Preferably, the length of the nozzle element is at least 1 millimeter greater than the length of the aerosol cooling element, more preferably at least 2 millimeters greater than the length of the aerosol cooling element, more preferably at least 3 millimeters greater than the length of the aerosol cooling element. A reduction in the length of the aerosol cooling element, as described above, may advantageously allow an increase in the length of other elements of the aerosol-generating article, such as the nozzle element. The potential technical benefits of providing a relatively long nozzle element are described above.

Preferably, in 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. Thus, the aerosol cooling element is capable of providing a desirable 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 invention may be further increased by circumscribing the aerosol cooling element by a rigid plug wrap, for example, a plug wrap 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.

As used herein, the term "radial hardness" of an element refers to the compressive strength in a direction transverse to a longitudinal axis of the element. The radial hardness of an aerosol-generating article around an element can be determined by applying a load through the article at the element location, transverse to the longitudinal axis of the article, and measuring the depressed average (mean) diameters of the articles. The radial hardness is given by:

hardness(o/0) =—±-* lo o %

Radial n s

where D<s> is the original (undepressed) diameter and Dd is the depressed diameter after a stated load has been applied for a stated duration. The harder the material, the closer the hardness approaches 100 percent.

To determine the hardness of a portion (such as an aerosol cooling element provided in the form of a segment of hollow tube) of an aerosol article, the aerosol-generating articles shall be aligned parallel in a plane and the same portion of each aerosol-generating article to be tested shall be subjected to a stated load for a stated duration. This test is performed by using a well-known DD60A densitometer device (manufactured and commercially available from Heinr Borgwaldt GmbH, Germany), which is equipped with a measuring head for aerosol-generating articles such as cigarettes and with a receptacle for the aerosol-generating articles.

The load is applied by using two cylindrical load-applying bars, which extend through the diameter of all aerosol-generating articles at once. In accordance with the standard test method for this instrument, the test should be conducted so that 20 points of contact are made between the aerosol-generating articles and the cylindrical bars to apply the load. In some cases, the hollow tube segments to be tested may be long enough so that only 10 aerosol-generating articles are needed to form 20 points of contact, with each smoking article in contact with both load-applying bars (because they are long enough to extend between the bars). In other cases, if the support members are too short to accomplish this, 20 aerosol-generating articles should be used to form the 20 points of contact, with each aerosol-generating article in contact with only one of the load-applying bars, as described below.

Two additional stationary cylindrical bars are located below the aerosol-generating articles, to support the aerosol-generating articles and counteract the load applied by each of the load-applying cylindrical bars.

For the standard operating procedure for such an apparatus, a total load of 2 kg is applied for a duration of 20 seconds. After 20 seconds have elapsed (and the load is still applied to the smoking articles), the depression in the cylindrical bars is determined to apply the load and then used to calculate the hardness from the equation above. The temperature is maintained in the region of 22 degrees Celsius ± 2 degrees. The test described above is referred to as the DD60A Test. The standard way to measure filter hardness is when the aerosol-generating article has not been consumed. Additional information regarding the measurement of average radial hardness can be found in, for example, U.S. patent application publication number 2016/0128378.

The aerosol cooling element can be formed from any suitable material or combination of materials. For example, the aerosol cooling element can be formed from one or more materials selected from the group consisting of: cellulose acetate; cardboard; crepe paper, such as heat-resistant crepe paper or parchment crepe 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 between about 0 millimeters of H2O (about 0 Pa) to about 20 millimeters of H2O (about 100 Pa), more preferably between about 0 millimeters of H2O (about 0 Pa) to about 10 millimeters of H2O (about 100 Pa).

In aerosol-generating articles according to the present invention, the total RTD of the article depends essentially on the RTD of the rod and optionally on the RTD of the upstream nozzle and/or 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 such, contribute essentially only marginally to the total RTD of the aerosol-generating article.

The vent zone comprises a plurality of perforations through the peripheral wall of the aerosol-cooling element. Preferably, the vent zone comprises at least one circumferential row of perforations. In some preferred embodiments, the vent zone may comprise two circumferential rows of perforations. For example, the perforations may be formed in line during manufacture of the aerosol-generating article. Preferably, each circumferential row of perforations comprises 8 to 30 perforations.

An aerosol-generating article according to the present invention may have a ventilation level of at least about 5 percent.

The term "ventilation level" is used throughout this description to denote a volume ratio between the airflow admitted to the aerosol-generating article through the ventilation zone (ventilation airflow) and the sum of the aerosol 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 aerosol-generating article has a ventilation level of at least about 25 percent. The aerosol-generating article preferably has a ventilation level of less than about 60 percent. An aerosol-generating article according to the present invention preferably has a ventilation level of less than or equal to about 45 percent. More preferably, an aerosol-generating article according to the present invention has a ventilation level of less than or equal to about 40 percent, even more preferably less than or equal to about 35 percent.

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 wishing to be bound by theory, the inventors have discovered that the temperature drop caused by the admission of cooler external air into the hollow tubular segment through the vent zone can have an advantageous effect on the nucleation and growth of aerosol particles.

The formation of an aerosol from a gaseous mixture containing several chemical species depends on a delicate interplay between nucleation, evaporation, condensation, and coalescence, all while accounting for variations in vapor concentration, temperature, and velocity fields. The so-called classical nucleation theory is based on the assumption that a fraction of the molecules in the gas phase are large enough to remain coherent for a long time with sufficient probability (e.g., a probability of one-half). These molecules represent some kind of critical, threshold clusters of molecules among transient molecular aggregates, meaning that, on average, smaller clusters of molecules are likely to disintegrate fairly quickly in the gas phase, while larger clusters are, on average, likely to grow. Such a critical cluster is identified as the key nucleation nucleus from which droplets are expected to grow due to the condensation of vapor molecules. Newly nucleated virgin droplets are assumed to emerge with a certain original diameter and can then grow by several orders of magnitude. This is facilitated and can be enhanced by rapid cooling of the surrounding vapor, which induces condensation. In this regard, it is useful to note that evaporation and condensation are two sides of the same mechanism, specifically, gas-liquid mass transfer. While evaporation refers to the net mass transfer from liquid droplets to the gas phase, condensation is the net mass transfer from the gas phase to the droplet phase. Evaporation (or condensation) will cause the droplets to shrink (or grow), but it will not change the number of droplets.

In this scenario, which can be further complicated by coalescence phenomena, temperature and cooling rate can play a critical role in determining how the system responds. In general, different cooling rates can lead to significantly different temporal behaviors in terms of liquid phase (droplet) formation, because the nucleation process is typically nonlinear. Without wishing to be bound by theory, it is hypothesized that cooling can lead to a rapid increase in droplet number concentration, followed by a sharp, short-lived increase in this growth (nucleation burst). This nucleation burst would appear to be more significant at lower temperatures. Furthermore, it would appear that higher cooling rates may favor an earlier onset of nucleation. Conversely, a reduction in the cooling rate would appear to have a favorable effect on the final size that aerosol droplets ultimately reach.

Therefore, the rapid cooling induced by the admission of external air into the hollow tubular segment through the ventilation zone can be used favorably to promote the nucleation and growth of aerosol droplets. However, at the same time, the admission of external air into the hollow tubular segment has the immediate disadvantage of diluting the aerosol stream delivered to the consumer.

The inventors have surprisingly discovered that the dilution effect on the aerosol—which can be assessed by measuring, in particular, the effect on the delivery of aerosol former (such as glycerol) included 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 between 25 percent and 50 percent, and even more preferably between 28 and 42 percent, lead to particularly satisfactory glycerol delivery values. At the same time, the extent of nucleation and, consequently, the delivery of nicotine and aerosol former (e.g., glycerol) are improved.

The inventors have surprisingly discovered how the favorable effect of enhanced nucleation promoted by rapid cooling induced by the introduction of ventilation air into the article is able to significantly counteract the less desirable effects of dilution. As such, satisfactory aerosol delivery values are consistently achieved with aerosol-generating articles according to the invention.

This is particularly advantageous with “short” aerosol-generating articles, such as those wherein a 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 wherein a total 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. As will be appreciated, 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 become available for delivery to the consumer.

Furthermore, because the vented hollow tubular segment does not substantially contribute to the total RTD of the aerosol-generating article, in aerosol-generating articles according to the invention the total RTD of the article can be advantageously tuned by adjusting the length and density of the aerosol-generating substrate rod or the length and optionally the length and density of a segment of filtration material that forms part of the mouthpiece or the length and density of a segment of filtration material that is provided upstream of the aerosol-generating substrate and the susceptor element. Aerosol-generating articles having a predetermined RTD can therefore be manufactured consistently and with high accuracy such that satisfactory levels of RTD for the consumer can be provided even in the presence of venting.

In some embodiments, the aerosol-generating article may further comprise an additional cooling element defining a plurality of longitudinally extending channels so as to make a high 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-like material that has been pleated, gathered, or folded to form the channels. The plurality of longitudinally extending channels may be defined by a single sheet that has been pleated, gathered, or folded to form multiple channels. The sheet may also have been crimped prior to being pleated, gathered, or folded. Alternatively, the plurality of longitudinally extending channels may be defined by multiple sheets that have been crimped, pleated, gathered, or folded to form multiple channels. In some embodiments, the plurality of longitudinally extending channels may be defined by multiple sheets that have been crimped, pleated, gathered, or folded together—that is, by two or more sheets that have been brought into the overlapping arrangement and then crimped, pleated, gathered, or folded as one. As used herein, the term 'sheet' denotes a sheet element having a width and length substantially greater than its thickness.

As used herein, the term 'longitudinal direction' refers to a direction extending along, or parallel to, the cylindrical axis of a bar. As used herein, the term 'crimped' denotes a sheet having a plurality of essentially parallel ridges or corrugations. Preferably, when the aerosol-generating article has been assembled, the essentially parallel ridges or corrugations extend in a longitudinal direction with respect to the bar. As used herein, the terms 'gathered', 'pleated', or 'folded' denote that a sheet of material is twisted, folded, or otherwise compressed or contracted substantially transversely to the cylindrical axis of the bar. A sheet may be crimped before it is crimped, pleated, or folded. A sheet may be crimped, pleated, or folded without first being crimped.

One such additional cooling element may have a total surface area of between about 300 square millimeters per millimeter of length and about 1000 square millimeters per millimeter of length.

The additional cooling element preferably offers low resistance to the passage of air through it. Preferably, the additional cooling element does not substantially affect the aspiration resistance of the aerosol-generating article. To achieve this, it is preferred that the porosity in a longitudinal direction be greater than 50 percent and that the airflow path through the additional cooling element be relatively uninhibited. The longitudinal porosity of the additional cooling element may be defined by a ratio of the cross-sectional area of the material forming the additional cooling element to an internal cross-sectional area of the aerosol-generating article in the portion containing the additional cooling element.

The additional cooling element preferably comprises a sheet-like material selected from the group consisting of a metallic foil, a polymeric foil, and an essentially non-porous paper or cardboard. In some embodiments, the aerosol cooling element may comprise a sheet-like 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 PLA sheet.

As described above, the intermediate hollow section comprises a support element arranged downstream of the aerosol-generating substrate bar. In particular, the support element may be located immediately downstream of the aerosol-generating substrate bar and may abut the aerosol-generating substrate bar.

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; paperboard; crepe paper, such as heat-resistant crepe paper or parchment crepe 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 member comprises a hollow tubular segment. In a preferred embodiment, the support member comprises a hollow tube of cellulose acetate.

Preferably, the support element is arranged substantially in alignment with the bar. This means that the length dimension of the support element is arranged to be approximately parallel to the longitudinal direction of the bar and the article, for example, within plus or minus 10 degrees parallel to the longitudinal direction of the bar. In preferred embodiments, the support element extends along the longitudinal axis of the bar. The support element preferably has an external diameter that is approximately equal to the external diameter of the aerosol-generating substrate bar and the external diameter of the aerosol-generating article.

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

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

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

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

In preferred embodiments, the support element 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, 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 element has a length of approximately 8 millimeters.

Preferably, the intermediate hollow section has a total length of no more than about 18 millimeters, more preferably no more than about 17 millimeters, and most preferably no more than 16 millimeters. A ratio of the length of the support member to the length of the aerosol-generating substrate rod may be from about 0.25 to about 1.

Preferably, a ratio of the length of the support member to the length of the aerosol-generating substrate bar is at least about 0.3, more preferably at least about 0.4, even more preferably at least about 0.5. In preferred embodiments, a ratio of the length of the support member to the length of the aerosol-generating substrate bar is less than about 0.9, more preferably less than about 0.8, even more preferably less than about 0.7.

In some embodiments, a ratio of the length of the support member to the length of the aerosol-generating substrate bar 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, a ratio of the length of the support member to the length of the aerosol-generating substrate bar 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, a ratio of the length of the support member to the length of the aerosol-generating substrate bar 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, a ratio of the length of the support member to the length of the aerosol-generating substrate bar is about 0.66.

A ratio of the length of the support member to the total length of the substrate of the aerosol-generating article may be from about 0.125 to about 0.375.

Preferably, a ratio of the length of the support member to 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. A ratio of the length of the support member to 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, a ratio of the length of the support member to the overall 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, a ratio of the length of the support member to the overall 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, a ratio of the length of the support member to the overall 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, a ratio of the length of the support element to the total length of the substrate of the aerosol-generating article is about 0.18.

Preferably, in 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. Thus, the support member is capable of providing a desirable level of hardness to the aerosol-generating article. If desired, the radial hardness of the support member of aerosol-generating articles according to the invention may be further increased by circumscribing the support member by a rigid cap wrapper, for example, a cap wrapper 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.

During insertion of an aerosol-generating article according to the invention into an aerosol-generating device to heat the aerosol-generating substrate, a user may need to apply some force to overcome the resistance of the aerosol-generating substrate of the aerosol-generating article to insertion. This may damage one or both of the aerosol-generating article and the aerosol-generating device. Furthermore, the application of force during insertion of the aerosol-generating article into the aerosol-generating device may displace the aerosol-generating substrate within the aerosol-generating article. This may result in the heating element of the aerosol-generating device not being properly aligned with the susceptor element provided within the aerosol-generating substrate, which may lead to uneven and inefficient heating of the aerosol-generating substrate of the aerosol-generating article. The support element is advantageously configured to resist downstream movement of the aerosol-generating substrate 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 between about 0 millimeters of H2O (about 0 Pa) to about 20 millimeters of H2O (about 100 Pa), more preferably between about 0 millimeters of H2O (about 0 Pa) to about 10 millimeters of H2O (about 100 Pa). Therefore, the support member preferably does not contribute to the total RTD of the aerosol-generating article.

The intermediate hollow section comprises both a support element comprising a first hollow tube segment and an aerosol cooling element comprising a second hollow tube segment. The internal diameter (D<sts>) of the second hollow tube segment is preferably larger than the internal diameter (D<fts>) of the first hollow tube segment.

In more detail, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is preferably at least about 1.25. More preferably, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is preferably at least about 1.3. Even more preferably, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is preferably at least about 1.4. In particularly preferred embodiments, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is at least about 1.5, more preferably at least about 1.6.

A ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is preferably less than or equal to about 2.5. More preferably, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is preferably less than or equal to about 2.25. Even more preferably, the ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is preferably less than or equal to about 2.

In some embodiments, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is from about 1.25 to about 2.5. Preferably, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is from about 1.3 to about 2.5. More preferably, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is from about 1.4 to about 2.5. In particularly preferred embodiments, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is from about 1.5 to about 2.5.

In other embodiments, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is from about 1.25 to about 2.25. Preferably, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is from about 1.3 to about 2.25. More preferably, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is from about 1.4 to about 2.25. In particularly preferred embodiments, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is from about 1.5 to about 2.25.

In further embodiments, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is from about 1.25 to about 2. Preferably, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is from about 1.3 to about 2. More preferably, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is from about 1.4 to about 2. In particularly preferred embodiments, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to the inner diameter (D<fts>) of the first hollow tubular segment is from about 1.5 to about 2.

In those embodiments wherein the article further comprises an elongated susceptor element disposed longitudinally within the aerosol-generating substrate, as described below, a ratio of an inner diameter (D<ft>) of the first hollow tubular segment to a width of the susceptor element is preferably at least about 0.2. More preferably, a ratio of an inner diameter (D<ft>) of the first hollow tubular segment to a width of the susceptor element is at least about 0.3. Even more preferably, a ratio of an inner diameter (D<ft>) of the first hollow tubular segment to a width of the susceptor element is at least about 0.4.

Additionally or alternatively, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to a width of the susceptor element is preferably at least about 0.2. More preferably, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to a width of the susceptor element is at least about 0.5. Even more preferably, a ratio of the inner diameter (D<sts>) of the second hollow tubular segment to a width of the susceptor element is at least about 0.8.

Preferably, a ratio of a cavity volume of the first hollow tubular segment to a cavity volume of the second hollow tubular segment is at least about 0.1. More preferably, a ratio of a cavity volume of the first hollow tubular segment to a cavity volume of the second hollow tubular segment is at least about 0.2. Even more preferably, a ratio of a cavity volume of the first hollow tubular segment to a cavity volume of the second hollow tubular segment is at least about 0.3.

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

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

In accordance with the present invention, the aerosol-generating substrate comprises a gel composition that includes 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 includes nicotine.

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

Advantageously, a stable gel composition comprising nicotine provides a predictable composition shape upon storage or shipment from manufacture to consumer. The stable gel composition comprising nicotine substantially maintains its shape. The stable gel composition comprising nicotine substantially does not release a liquid phase upon storage or shipment from manufacture to consumer. The stable gel composition comprising nicotine may provide a simple consumable design. This consumable may not need to be designed to contain a liquid, so a wider range of container materials and constructions may be contemplated.

The gel composition described herein may be combined with an aerosol-generating device to deliver a nicotine aerosol to the lungs at inhalation or airflow rates that are within the inhalation or airflow rates of a conventional smoking regimen. The aerosol-generating device may continuously heat the gel composition. A consumer may take a plurality of inhalations or “puffs” where each “puff” delivers a quantity of nicotine aerosol. The gel composition may be capable of delivering a high nicotine/low total particulate matter (TPM) aerosol to a consumer when heated, preferably continuously.

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

The gel composition includes an alkaloid compound, or a cannabinoid compound, or both an alkaloid compound and a cannabinoid compound. The gel composition may include one or more alkaloids. The gel composition may include one or more cannabinoids. The gel composition may include 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 containing one or more basic nitrogen atoms. Generally, 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 of their nitrogen atoms as part of a cyclic system, such as 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 species and fungi. In this description, the term “alkaloid compound” refers to both naturally occurring alkaloid compounds and synthetically manufactured alkaloid compounds.

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

Preferably, the composition of the gel includes nicotine.

The term “nicotine” refers to nicotine and nicotine derivatives such as freebase nicotine, nicotine salts and the like.

The term “cannabinoid compound” refers to any of a class of naturally occurring compounds found in parts of the cannabis plant, specifically the species Cannabis sativa, Cannabis indica, and Cannabis ruderalis. Cannabinoid compounds are especially concentrated in the female flower heads. Cannabinoid compounds naturally occurring in the cannabis plant include cannabidiol (CBD) and tetrahydrocannabinol (THC). In this description, the term “cannabinoid compounds” is used to describe both naturally derived cannabinoid compounds and synthetically manufactured cannabinoid compounds.

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

The gel may preferably include cannabidiol (CBD).

The composition of the gel may include nicotine and cannabidiol (CBD).

The composition of the gel may include nicotine, cannabidiol (CBD) and THC (tetrahydrocannabinol).

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

Preferably, nicotine is included in the gel compositions. Nicotine may be added to the composition in free base form or in salt form. The gel composition includes about 0.5 weight percent to about 10 weight percent nicotine, or about 0.5 weight percent to about 5 weight percent nicotine. Preferably, the gel composition includes about 1 weight percent to about 3 weight percent nicotine, or about 1.5 weight percent to about 2.5 weight percent nicotine, or about 2 weight percent nicotine. The nicotine component of the gel formulation may be the most volatile component of the gel formulation. In some aspects, water may be the most volatile component of the gel formulation and the nicotine component of the gel formulation may be the second most volatile component of the gel formulation.

The gel composition additionally includes an aerosol former. Ideally, the aerosol former should be substantially resistant to thermal degradation at the operating temperature of the associated aerosol-generating device. Suitable aerosol formers include, but are not limited to: polyhydric alcohols, such as triethylene glycol, 1,3-butanediol, and glycerin; 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 triethylene glycol, 1,3-butanediol, and glycerin (glycerol or propane-1,2,3-triol) or polyethylene glycol. The aerosol former is preferably glycerol.

The gel composition may include the majority of an aerosol former. The gel composition may include a mixture of water and the aerosol former wherein the aerosol former forms a majority (by weight) of the gel composition. The aerosol former may form at least about 50 percent by weight of the gel composition. The aerosol former 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 former may form about 70 percent by weight to about 80 percent by weight of the gel composition. The aerosol former may form about 70 percent by weight to about 75 percent by weight of the gel composition.

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

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

The term “gelling agent” refers to a compound that, when added homogeneously to a 50 percent by weight water/50 percent by weight glycerol mixture in an amount of about 0.3 percent by weight, forms a solid medium or support matrix conducive to a gel. Gelling agents include, but are not limited to, hydrogen-bonded crosslinking gelling agents and ionic crosslinking gelling agents.

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

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

Preferably, the gel composition comprises at least about 0.2 weight percent hydrogen-bonded crosslinking gelling agent. Alternatively or additionally, the gel composition preferably comprises at least about 0.2 weight percent ionic crosslinking gelling agent. Most preferably, the gel composition comprises at least about 0.2 weight percent hydrogen-bonded crosslinking gelling agent and at least about 0.2 weight percent ionic crosslinking gelling agent. The gel composition may comprise about 0.5 weight percent to about 3 weight percent hydrogen-bonded crosslinking gelling agent and about 0.5 weight percent to about 3 weight percent ionic crosslinking gelling agent, or about 1 weight percent to about 2 weight percent hydrogen-bonded crosslinking gelling agent and about 1 weight percent to about 2 weight percent ionic crosslinking gelling agent. The hydrogen-bonded crosslinking gelling agent and the ionic crosslinking gelling agent may be present in the gel composition in essentially equal amounts by weight.

The term “hydrogen bond crosslinking gelling agent” refers to a gelling agent that forms non-covalent crosslinks or physical crosslinks through hydrogen bonding. Hydrogen bonding is a type of electrostatic dipole-dipole attraction between molecules, not a covalent bond to a hydrogen atom. It results from the attractive force between a hydrogen atom covalently bonded to a highly electronegative atom, such as an N, O, or F atom, and another highly electronegative atom.

The hydrogen-bonded crosslinking gelling agent may include one or more of galactomannan, gelatin, agarose, konjac gum, or agar. The hydrogen-bonded crosslinking gelling agent may preferably include agar.

The gel composition preferably includes the hydrogen-bonded crosslinking gelling agent in a range of about 0.3 weight percent to about 5 weight percent. Preferably, the composition includes the hydrogen-bonded crosslinking gelling agent in a range of about 0.5 weight percent to about 3 weight percent. Preferably, the composition includes the hydrogen-bonded crosslinking gelling agent in a range of about 1 weight percent to about 2 weight percent.

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

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

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

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

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

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

The ionic crosslinking gelling agent may include low-acyl gellan, pectin, kappa carrageenan, iota carrageenan, or alginate. The ionic crosslinking gelling agent may preferably include low-acyl gellan.

The gel composition may include the ionic crosslinking gelling agent in a range of about 0.3 weight percent to about 5 weight percent. Preferably, the composition includes the ionic crosslinking gelling agent in a range of about 0.5 weight percent to about 3 weight percent. Preferably, the composition includes the ionic crosslinking gelling agent in a range of about 1 weight percent to about 2 weight percent.

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

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

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

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

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

The gel composition may include the hydrogen-bonded crosslinking gelling agent and the ionic crosslinking gelling agent in a ratio of about 3:1 to about 1:3. Preferably, the gel composition may include the hydrogen-bonded crosslinking gelling agent and the ionic crosslinking gelling agent in a ratio of about 2:1 to about 1:2. Preferably, the gel composition may include the hydrogen-bonded crosslinking gelling agent and the ionic crosslinking gelling agent in a ratio of about 1:1.

The gel composition may further include a viscosifying agent. The viscosifying agent combined with the hydrogen-bonded crosslinking gelling agent and the ionic crosslinking gelling agent appears to surprisingly withstand the solid medium and maintain the gel composition even when the gel composition comprises a high level of glycerol.

The term “viscosity enhancer” refers to a compound which, when added homogeneously to a 25°C, 50 weight percent water/50 weight percent glycerol mixture in an amount of 0.3 weight percent, increases the viscosity without leading to the formation of a gel, the mixture remaining or remaining in the fluid. Preferably, the viscosifying agent refers to a compound which, when added homogeneously to a 25°C, 50 weight percent water/50 weight percent glycerol mixture in an amount of 0.3 weight percent, 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 leading to the formation of a gel, the mixture remaining or remaining in the fluid. Preferably, the viscosifying agent refers to a compound which when added homogeneously to a 25°C 50 weight percent water/50 weight percent glycerol mixture, in an amount of 0.3 weight percent, increases the viscosity at least 2 times, or at least 5 times, or at least 10 times, or at least 100 times greater than before the addition, at a shear rate of 0.1 s-1, without leading to the formation of a gel, the mixture remains or remains fluid.

The viscosity values cited in the present description can be measured by using a Brookfield RVT viscometer rotating a disc-type RV#2 spindle at 25°C at a speed of 6 revolutions per minute (rpm).

The gel composition preferably includes the viscosifying agent in a range of about 0.2 weight percent to about 5 weight percent. Preferably, the composition includes the viscosifying agent in a range of about 0.5 weight percent to about 3 weight percent. Preferably, the composition includes the viscosifying agent in a range of about 0.5 weight percent to about 2 weight percent. Preferably, the composition includes the viscosifying agent in a range of about 1 weight percent to about 2 weight percent.

The viscosifying agent may include one or more of xanthan gum, carboxymethylcellulose, microcrystalline cellulose, methylcellulose, gum arabic, guar gum, lambda carrageenan, or starch. The viscosifying agent may preferably include xanthan gum.

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

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

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

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

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

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

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

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

The gel composition may further include a divalent cation. Preferably, the divalent cation includes calcium ions, such as calcium lactate in solution. Divalent cations (such as calcium ions) may aid in gel formation in compositions that include gelling agents, such as an ionic crosslinking gelling agent, for example. The ionic effect may aid in gel formation. The divalent cation may be present in the gel composition in a range of about 0.1 to about 1 percent by weight, or about 0.5 percent by weight to about 1 percent by weight.

The gel composition may further include an acid. The acid may comprise a carboxylic acid. The carboxylic acid may include a ketone group. Preferably, the carboxylic acid may include 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 (such as lactic acid). The lactic acid surprisingly improves the stability of the gel composition even over similar carboxylic acids. The carboxylic acid may aid in gel formation. The carboxylic acid may reduce the variation in the concentration of the alkaloid compound, or the concentration of the cannabinoid compound, or both the concentration of the alkaloid compound and the cannabinoid compound within the gel composition during storage. The carboxylic acid may reduce the variation in the nicotine concentration within the gel composition during storage.

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

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

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

The gel composition preferably comprises some water. The gel composition is more stable when the composition comprises some water. Preferably, the gel composition comprises 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 comprises at least about 10 percent by weight or at least about 15 percent by weight of water.

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

Preferably, the aerosol-generating substrate comprises between about 150 mg and about 350 mg of the gel composition.

Preferably, in embodiments comprising a gel composition, the aerosol-generating substrate comprises a porous medium loaded with the gel composition. The advantage of a porous medium loaded with the gel composition is that the gel composition is retained within the porous medium, and this can aid in manufacturing, storing, or transporting the gel composition. It can help maintain the desired shape of the gel composition, especially during manufacturing, transport, or use.

The term “porous” is used in the present description to refer to a material that provides a plurality of pores or openings that allow air to pass through the material.

The porous medium may be any suitable porous material capable of containing or retaining the gel composition. Ideally, the porous medium may allow the gel composition to move within it. In specific embodiments, the porous medium comprises natural, synthetic, or semi-synthetic materials, or combinations thereof. In certain embodiments, the porous medium comprises sheet-like material, foam, or fibers, e.g., loose fibers; or a combination thereof. In specific embodiments, the porous medium comprises a woven, nonwoven, 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-like material, e.g., 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 crimped or ground. In preferred embodiments, the porous medium is crimped. In alternative embodiments, the porous medium comprises ground porous medium. The crimping or grinding process may occur before or after the medium is filled with the gel composition.

Crimping the sheet material has the benefit of improving the structure, allowing passages through it. The passages through the crimp sheet material help load gel, retain gel, and also allow fluid to pass through the crimp sheet material. Therefore, using crimp sheet material as a porous medium has its advantages.

Crushing gives a high surface area to volume ratio to the medium, making it able to absorb gel easily.

In specific embodiments, the sheet-like material is a composite material. Preferably, the sheet-like material is porous. The sheet-like material can aid in manufacturing the tubular element comprising a gel. The sheet-like material can aid in introducing an active agent to the tubular element comprising a gel. The sheet-like material can aid in stabilizing the structure of the tubular element comprising a gel. The sheet-like material can aid in transporting or storing the gel. The use of a sheet-like material allows, or aids, in adding structure to the porous medium, for example, by crimping the sheet-like material.

The porous medium can be a thread. The thread can comprise, for example, cotton, paper, or acetate tow. The thread can also be filled with gel like any other porous medium. One advantage of using a thread as a porous medium is that it can help facilitate manufacturing.

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

The porous medium loaded with the gel composition is preferably provided within 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 part of a multi-component element, which ideally will be longer in longitudinal length than in width. Typically, the tubular element is cylindrical, but not necessarily. For example, the tubular element may have an oval, polygonal, triangular, rectangular, or random cross-section.

The tubular element preferably comprises a first longitudinal passage. The tubular element is preferably formed from a sheath defining the first longitudinal passage. The sheath is preferably a water-resistant sheath. This water-resistant property of the sheath can be achieved by using a water-resistant material, or by treating the sheath material. This can be achieved by treating one or both sides of the sheath. Being water-resistant would help prevent loss of structure, stiffness, or rigidity. It can also help prevent gel or liquid leakage, especially when using gels with a fluid structure.

Preferably, the plug of the porous medium loaded with the gel composition is circumscribed by a water-repellent envelope.

In certain preferred embodiments of the present invention, an elongated susceptor element is disposed substantially longitudinally within the aerosol-generating substrate rod and is in thermal contact with the aerosol-generating substrate.

As used herein, with reference to the present invention, the term “susceptor element” refers to a material capable of converting electromagnetic energy into heat. When placed within a fluctuating electromagnetic field, eddy currents induced in the susceptor element cause the susceptor element to heat. Because the elongated susceptor element is placed in thermal contact with the aerosol-generating substrate, the aerosol-generating substrate is heated by the susceptor element.

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

The susceptor element is arranged essentially longitudinally within the bar. This means that the length dimension of the elongated susceptor element is arranged to be approximately parallel to the longitudinal direction of the bar, for example, within plus or minus 10 degrees parallel to the longitudinal direction of the bar. In preferred embodiments, the elongated susceptor element can be positioned radially centrally within the bar, extending along the longitudinal axis of the bar.

Preferably, the susceptor element extends to a downstream end of the rod of the aerosol-generating article. In some embodiments, the susceptor element may extend to an upstream end of the rod of the aerosol-generating article. In particularly preferred embodiments, the susceptor element is 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 susceptor element is preferably in the form of a pin, bar, strip or sheet.

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

A ratio of the length of the susceptor element to the total length of the substrate of the aerosol-generating article may be from about 0.2 to about 0.35.

Preferably, a ratio of the length of the susceptor element to the overall 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. A ratio of the length of the susceptor element to the overall 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, a ratio of the length of the susceptor element to the overall 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, a ratio of the length of the susceptor element to the overall 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, a ratio of the length of the susceptor element to the overall 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, a ratio of the length of the susceptor element to the total length of the substrate of the aerosol-generating article is about 0.27.

The susceptor element preferably has a width of about 1 millimeter to about 5 millimeters.

The susceptor element may generally have a thickness of about 0.01 millimeters to about 2 millimeters, for example, about 0.5 millimeters to about 2 millimeters. In some embodiments, the susceptor element preferably has a thickness of about 10 micrometers to about 500 micrometers, more preferably about 10 micrometers to about 100 micrometers.

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

If the susceptor element is in the form of a strip or sheet, the strip or sheet preferably has a rectangular shape, preferably having a width of about 2 millimeters to about 8 millimeters, more preferably about 3 millimeters to about 5 millimeters. For example, a susceptor element in the form of a strip or sheet may have a width of about 4 millimeters.

If the susceptor element is in the form of a strip or sheet, the strip or sheet preferably has a rectangular shape and a thickness of about 0.03 millimeters to about 0.15 millimeters, more preferably about 0.05 millimeters to about 0.09 millimeters. For example, a susceptor element in the form of a strip or sheet may have a thickness of about 0.07 millimeters.

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

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

Preferably, the elongated susceptor element has a length that is the same as or shorter than the length of the aerosol-generating substrate. Preferably, the elongated susceptor element has the same length as the aerosol-generating substrate.

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

A preferred susceptor element may comprise or consist of a ferromagnetic material, for example, a ferromagnetic alloy, ferritic iron, or a ferromagnetic steel or stainless steel. A suitable susceptor element may be, or comprise, aluminum. Preferred susceptor elements may be formed from 400 series stainless steels, for example, grade 410, grade 420, or grade 430 stainless steel. Different materials will dissipate different amounts of energy when placed within electromagnetic fields having similar values of frequency and field strength.

Therefore, susceptor element parameters such as material type, length, width, and thickness can all be altered to provide a desired energy dissipation within a known electromagnetic field. Preferred susceptor elements can be heated to temperatures exceeding 250 degrees Celsius.

Suitable susceptor elements may comprise a non-metallic core with a metal layer disposed over the non-metallic core, for example, metallic traces formed on a surface of a ceramic core. A susceptor element may have an outer protective layer, for example, a ceramic protective layer or a glass protective layer, encapsulating the susceptor element. The susceptor element may comprise a protective coating formed from an inert glass, ceramic, or metal, which is formed over a core of material of the susceptor element.

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

The susceptor element may be a multi-material susceptor element and may comprise a first susceptor element material and a second susceptor element material. The first susceptor element material is disposed in intimate physical contact with the second susceptor element material. The second susceptor element material preferably has a Curie temperature that is less than 500 degrees Celsius. The first susceptor element material is preferably used primarily to heat the susceptor element when the susceptor element is placed in a fluctuating electromagnetic field. Any suitable material may be used. For example, the first susceptor element material may be aluminum, or it may be a ferrous material such as stainless steel. The second susceptor element material is preferably used primarily to indicate when the susceptor element has reached a specific temperature, which temperature is the Curie temperature of the second susceptor element material. The Curie temperature of the second susceptor element material may be used to regulate the temperature of the entire susceptor element during operation. Therefore, the Curie temperature of the second susceptor element material should be below the ignition point of the aerosol-generating substrate. Suitable materials for the second susceptor element material may include nickel and certain nickel alloys.

By providing a susceptor element having at least a first and a second susceptor element material, with the second susceptor element material having a Curie temperature and the first susceptor element material not having a Curie temperature, or the first and second susceptor element materials having different first and second Curie temperatures, heating of the aerosol-generating substrate and temperature control of the heating can be separated. The first susceptor element material is preferably a magnetic material having a Curie temperature that is above 500 degrees Celsius. It is advantageous, from the standpoint of heating efficiency, for the Curie temperature of the first susceptor element material to be above any maximum temperature to which the susceptor element should be capable of heating. The second Curie temperature may preferably be selected to be less than 400 degrees Celsius, preferably less than 380 degrees Celsius, or less than 360 degrees Celsius. It is preferred that the second susceptor element material be a magnetic material selected to have a second Curie temperature that is substantially the same as a desired maximum heating temperature. That is, it is preferred that the second Curie temperature be approximately the same as the temperature to which the susceptor element must be heated to generate an aerosol from the aerosol-generating substrate. The second Curie temperature may, for example, be within the range of 200 degrees Celsius to 400 degrees Celsius, or between 250 degrees Celsius and 360 degrees Celsius. The second Curie temperature of the second susceptor element material may, for example, be selected such that, when heated by a susceptor element at a temperature equal to the second Curie temperature, the overall average temperature of the aerosol-generating substrate does not exceed 240 degrees Celsius.

The aerosol-generating articles of the present invention may further comprise an upstream element located upstream of and adjacent to the aerosol-generating substrate, wherein the upstream section comprises at least one upstream element. The upstream element advantageously prevents direct physical contact with the upstream end of the aerosol-generating substrate. In particular, when the aerosol-generating substrate comprises a susceptor element, the upstream element may prevent direct physical contact with the upstream end of the susceptor element. This helps prevent displacement or deformation of the susceptor element during handling or transport of the aerosol-generating article. This, in turn, helps ensure the shape and position of the susceptor element. Furthermore, the presence of an upstream element helps prevent any loss of the substrate.

The upstream element can also advantageously compensate for any potential reduction in RTD, for example, due to evaporation of the gel composition upon heating of the aerosol-generating substrate rod during use.

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

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

The upstream element can be made of a porous material or can comprise a plurality of openings. This can be achieved, for example, through laser perforations. Preferably, the plurality of openings are distributed evenly over the cross-section of the upstream element.

The porosity or permeability of the upstream element may advantageously vary to provide a desirable overall aspiration resistance of the aerosol-generating article.

Preferably, the RTD of the upstream element is at least about 5 millimeters of H2O. More preferably, the RTD of the upstream element is at least about 10 millimeters of H2O. Even more preferably, the RTD of the upstream element is at least about 15 millimeters of H2O. In particularly preferred embodiments, the RTD of the upstream element is at least about 20 millimeters of H2O.

The RTD of the upstream element is preferably less than or equal to about 80 millimeters of H2O. More preferably, the RTD of the upstream element is less than or equal to about 60 millimeters of H2O. Even more preferably, the RTD of the upstream element is less than or equal to about 40 millimeters of H2O.

In some embodiments, the RTD of the upstream element is from about 5 millimeters of H2O to about 80 millimeters of H2O, preferably from about 10 millimeters of H2O to about 80 millimeters of H2O, more preferably from about 15 millimeters of H2O to about 80 millimeters of H2O, even more preferably from about 20 millimeters of H2O to about 80 millimeters of H2O. In other embodiments, the RTD of the upstream element is from about 5 millimeters of H2O to about 60 millimeters of H2O, preferably from about 10 millimeters of H2O to about 60 millimeters of H2O, more preferably from about 15 millimeters of H2O to about 60 millimeters of H2O, even more preferably from about 20 millimeters of H2O to about 60 millimeters of H2O. In further embodiments, the RTD of the upstream element is from about 5 millimeters H2O to about 40 millimeters H2O, preferably from about 10 millimeters H2O to about 40 millimeters H2O, more preferably from about 15 millimeters H2O to about 40 millimeters H2O, even more preferably from about 20 millimeters H2O to about 40 millimeters H2O.

Preferably, the RTD of the upstream element is greater than the RTD of the nozzle element. Preferably, the RTD of the upstream element is at least 1.5 times the RTD of the nozzle, more preferably at least 2 times the RTD of the nozzle, and most preferably at least 2.5 times the RTD of the nozzle 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 nozzle element to be minimized so that the filtration effect on the aerosol can also be minimized if desired.

In alternative embodiments, the upstream element may be formed from a material that is impermeable to air. In such embodiments, the aerosol-generating article may be configured such that air flows toward the aerosol-generating substrate rod through suitable venting means provided in a casing.

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

Preferably, the upstream element is made of a heat-resistant material. For example, the upstream element is preferably made of a material that withstands temperatures of up to 350 degrees Celsius. This ensures that the upstream element is not adversely affected by the heating means used to heat 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 between about 1 millimeter and about 10 millimeters, more preferably between about 3 millimeters and about 8 millimeters, most preferably between about 4 millimeters and about 6 millimeters. In a particularly preferred embodiment, the upstream element has a length of about 5 millimeters. The length of the upstream element may advantageously vary to provide the desired overall length of the aerosol-generating article. For example, where it is desired to reduce the length of one of the other components of the aerosol-generating article, the length of the upstream element may be increased to maintain the same overall length of the article.

The upstream element preferably has an essentially homogeneous structure. For example, the upstream element may be essentially homogeneous in texture and appearance. The upstream element may, for example, have a continuous and regular surface over its entire cross-section. The upstream element may, for example, have no recognizable symmetries.

The upstream element is preferably circumscribed by a wrapper. The wrapper circumscribing the upstream element is preferably a rigid plug wrapper, for example, a plug wrapper 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 of about 35 millimeters to about 100 millimeters.

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

A total length of an aerosol-generating article according to the invention is preferably less than or equal to 70 millimeters. More preferably, a total length of an aerosol-generating article according to the invention is preferably less than or equal to 60 millimeters. Even more preferably, a total length of an aerosol-generating article according to the invention is preferably less than or equal to 50 millimeters.

In some embodiments, an 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, an 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, an 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 illustrative embodiment, an overall length of the aerosol-generating article is about 45 millimeters.

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

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

In some embodiments, the aerosol-generating article has an external 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 external 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 external 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 invention, a diameter (D<me>) of the aerosol-generating article at the mouth-side end is (preferably) larger than a diameter (D<de>) of the aerosol-generating article at the distal end. In more detail, a ratio (D<me>/D<de>) between the diameter of the aerosol-generating article at the mouth-side end and the diameter of the aerosol-generating article at the distal end is (preferably) at least about 1.005.

Preferably, a ratio (D<me>/D<de>) between the diameter of the aerosol-generating article at the mouthside end and the diameter of the aerosol-generating article at the distal end is (preferably) at least about 1.01. More preferably, a ratio (D<me>/D<de>) between the diameter of the aerosol-generating article at the mouthside end and the diameter of the aerosol-generating article at the distal end is at least about 1.02. Even more preferably, a ratio (D<me>/D<de>) between the diameter of the aerosol-generating article at the mouthside end and the diameter of the aerosol-generating article at the distal end is at least about 1.05.

A ratio (D<me>/D<de>) between the diameter of the aerosol-generating article at the mouthside 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, a ratio (D<me>/D<de>) between the diameter of the aerosol-generating article at the mouthside 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, a ratio (D<me>/D<de>) between the diameter of the aerosol-generating article at the mouthside 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, a ratio (D<me>/D<de>) between the diameter of the aerosol-generating article at the mouthside end and the diameter of the aerosol-generating article at the distal end is less than or equal to about 1.15 or 1.10.

In some preferred embodiments, a ratio (D<me>/D<de>) between the diameter of the aerosol-generating article at the mouth-side end and the diameter of the aerosol-generating article at the distal end is about 1.01 to 1.30, more preferably 1.02 to 1.30, even more preferably 1.05 to 1.30.

In other embodiments, a ratio (D<me>/D<de>) between the diameter of the aerosol-generating article at the mouthside end and the diameter of the aerosol-generating article at the distal end is about 1.01 to 1.25, more preferably 1.02 to 1.25, even more preferably 1.05 to 1.25. In further embodiments, a ratio (D<me>/D<de>) between the diameter of the aerosol-generating article at the mouthside end and the diameter of the aerosol-generating article at the distal end is about 1.01 to 1.20, more preferably 1.02 to 1.20, even more preferably 1.05 to 1.20. In still further embodiments, a ratio (D<me>/D<de>) between the diameter of the aerosol-generating article at the mouth-side end and the diameter of the aerosol-generating article at the distal end is about 1.01 to 1.15, more preferably 1.02 to 1.15, even more preferably 1.05 to 1.15.

For example, the outer diameter of the article may be substantially constant over a distal portion of the article 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 be tapered over 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 about 70 percent of the way along the length of the aerosol-generating article from the downstream end.

Providing an arrangement of elements that gives a center of mass that is closer to the upstream end than to the downstream end results in an aerosol-generating article that has a weight imbalance, with a heavier upstream end. This weight imbalance may advantageously provide haptic feedback to the consumer to allow them to distinguish between the upstream and downstream ends so that the correct end can be inserted into an aerosol-generating device. This may be particularly beneficial 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 aerosol-generating articles according to the invention, in which both the aerosol cooling element and the support element are present, these are preferably wrapped together in a combined wrapper. The combined wrapper encloses the aerosol cooling element and the support element, but does not enclose an additional downstream element, such as a nozzle element.

In these embodiments, the aerosol cooling element and the support element are combined before being circumscribed by the combined envelope, before they are further combined with the nozzle segment.

From a manufacturing perspective, this is advantageous because it allows for shorter aerosol-generating articles to be assembled.

In general, it can be difficult to handle individual elements that are shorter than their diameter. For example, for elements with a diameter of 7 millimeters, a length of approximately 7 millimeters represents a threshold value that is preferable not to approach. However, a 10 millimeter aerosol cooling element can be combined with a pair of 7 millimeter support elements on each side (and potentially with other elements such as the aerosol-generating substrate bar, etc.) to provide a 24 millimeter hollow segment, which is subsequently cut into two intermediate 12 millimeter hollow sections.

In particularly preferred embodiments, the other components of the aerosol-generating article are individually enclosed within their own envelope. In other words, the upstream element, the aerosol-generating substrate bar, the support element, and the aerosol-cooling element are all individually enveloped. The support element and the aerosol-cooling element are combined to form the intermediate hollow section. This is achieved by enclosing the support element and the aerosol-cooling element by means of a combined envelope. The upstream element, the aerosol-generating substrate bar, and the intermediate hollow section are then combined together with an outer envelope. They are subsequently combined with the nozzle element—which has a separate envelope—by means of 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. A useful way to determine this is to measure the water contact angle. The “water contact angle” is the angle, conventionally measured through the liquid, where a liquid/vapor interface meets a solid surface. It quantifies the wettability of a solid surface by a liquid through Young’s equation. Hydrophobicity, or the water contact angle, can be determined using TAPPI Test Method T558, and the result is presented as an interfacial contact angle and reported in “degrees” and can range from near zero to nearly 180 degrees.

In preferred embodiments, the hydrophobic wrapper is one that includes a paper layer having a contact angle with water of about 30 degrees or greater, and preferably about 35 degrees or greater, or about 40 degrees or greater, or about 45 degrees or greater.

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

In a particularly preferred embodiment, an aerosol-generating article according to the present invention comprises, in linear sequential arrangement, an upstream element, an aerosol-generating substrate bar located immediately downstream of the upstream element, a support element located immediately downstream of the aerosol-generating substrate bar, an aerosol-cooling element located immediately downstream of the support element, a nozzle element located immediately downstream of the aerosol-cooling element, and an outer casing circumscribing the upstream element, the support element, the aerosol-cooling element, and the nozzle element.

In more detail, the aerosol-generating substrate bar may adjoin the upstream element. The support element may adjoin the aerosol-generating substrate bar. The aerosol-cooling element may adjoin the support element. The nozzle element may adjoin the aerosol-cooling element.

The aerosol-generating article has an essentially cylindrical shape and an external 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, and the nozzle 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 wrapped in a rigid plug wrapper.

The aerosol-generating article comprises an elongated susceptor element that is disposed substantially longitudinally within the aerosol-generating substrate rod and is in thermal contact with the aerosol-generating substrate. The susceptor element is in the form of a strip or sheet, has a length substantially equal to the length of the aerosol-generating substrate rod, and has a thickness of approximately 60 micrometers.

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

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

The mouthpiece is shaped like a segment of low-density cellulose acetate filter.

The aerosol-generating substrate bar comprises an aerosol-generating substrate comprising a gel composition.

In the following, the invention will be further described with reference to the attached drawings of Figure 1 which shows a schematic side sectional view of an aerosol-generating article according to the invention.

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

The aerosol-generating article has a total length of approximately 45 millimeters.

The downstream section 14 comprises a support member 22 which is located immediately downstream of the bar 12 of the aerosol-generating substrate, the support member 22 being in longitudinal alignment with the bar 12. In the embodiment of Figure 1, the upstream end of the support member 22 abuts the downstream end of the bar 12 of the aerosol-generating substrate. Furthermore, the downstream section 14 comprises an aerosol cooling element 24 which is located immediately downstream of the support member 22, the aerosol cooling element 24 being in longitudinal alignment with the bar 12 and the support member 22. In the embodiment of Figure 1, the upstream end of the aerosol cooling element 24 abuts the downstream end of the support member 22.

As will be apparent from the following description, the support member 22 and the aerosol cooling element 24 together define an intermediate hollow section 50 of the aerosol-generating article 10. As a whole, the intermediate hollow section 50 contributes substantially nothing to the total RTD of the aerosol-generating article. An RTD of the intermediate hollow section 50 as a whole is essentially 0 millimeters of 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 extending from an upstream end 30 of the first hollow tubular segment to a downstream end 32 of the first hollow tubular segment 26. The internal cavity 28 is essentially empty, and therefore essentially unrestricted airflow is permitted along the internal cavity 28. The first hollow tubular segment 26—and, as a consequence, the support member 22—contributes essentially nothing to the total 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 essentially 0 millimeters H2O.

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. Therefore, a thickness of a 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 made of cellulose acetate. The second hollow tubular segment 34 defines an internal cavity 36 extending from an upstream end 38 of the second hollow tubular segment to a downstream end 40 of the second hollow tubular segment 34. The internal cavity 36 is essentially empty, and therefore essentially unrestricted airflow is permitted along the internal cavity 36. The second hollow tubular segment 34—and, as a consequence, the aerosol cooling element 24—contributes essentially nothing to the total 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 essentially 0 millimeters H2O.

The second hollow tubular segment 34 has a length of about 8 millimeters, an outer diameter of about 7.25 millimeters, and an inner diameter (D<sts>) of about 3.25 millimeters. Therefore, a thickness of a peripheral wall of the second hollow tubular segment 34 is about 2 millimeters. Therefore, a ratio of the inner diameter (D<fts>) of the first hollow tubular segment 26 to the inner diameter (D<sts>) of the second hollow tubular segment 34 is about 0.75.

The aerosol-generating article 10 comprises a venting zone 60 that is provided at a location along the second hollow tubular segment 34. In more detail, the venting zone is provided approximately 2 millimeters from the upstream end 38 of the second hollow tubular segment 34. The venting level of the aerosol-generating article 10 is approximately 25 percent.

In the embodiment of Figure 1, the downstream section 14 further comprises a nozzle element 42 at a location downstream of the intermediate hollow section 50. In more detail, the nozzle element 42 is positioned immediately downstream of the aerosol cooling element 24. As shown in the drawing of Figure 1, an upstream end of the nozzle element 42 abuts the downstream end 40 of the aerosol cooling element 24.

The nozzle element 42 is provided in the form of a cylindrical plug of low-density cellulose acetate.

The nozzle element 42 has a length of approximately 12 millimeters and an external diameter of approximately 7.25 millimeters. The RTD of the nozzle element 42 is approximately 12 millimeters of H2O.

The bar 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:

T l 1: m i i n l l

The rod 12 of the aerosol-generating substrate has an external diameter of approximately 7.25 millimeters and a length of approximately 12 millimeters.

The aerosol-generating article 10 further comprises an elongated susceptor element 44 within the bar 12 of the aerosol-generating substrate. In more detail, the susceptor element 44 is arranged essentially longitudinally within the aerosol-generating substrate, such that it is approximately parallel to the longitudinal direction of the bar 12. As shown in the drawing of Figure 1, the susceptor element 44 is positioned at a radially central position within the bar and effectively extends along the longitudinal axis of the bar 12.

The susceptor element 44 extends from an upstream end to a downstream end of the rod 12. In effect, the susceptor element 44 has essentially the same length as the rod 12 of the aerosol-generating substrate.

In the embodiment of Figure 1, the susceptor 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 that is located immediately upstream of the bar 12 of the aerosol-generating substrate, the upstream element 46 being in longitudinal alignment with the bar 12. In the embodiment of Figure 1, the downstream end of the upstream element 46 abuts the upstream end of the bar 12 of the aerosol-generating substrate. This advantageously prevents the susceptor element 44 from becoming detached. Furthermore, this ensures that the consumer cannot accidentally come into contact with the heated susceptor element 44 after use.

The upstream element 46 is provided in the form of a cylindrical plug of cellulose acetate circumscribed by a rigid envelope. The upstream element 46 has a length of approximately 5 millimeters. The RTD of the upstream element 46 is approximately 30 millimeters of H2O.

Claims (14)

1. An aerosol-generating article (10) for producing an inhalable aerosol upon heating, the aerosol-generating article (10) comprising: an aerosol-generating substrate stick (12) comprising a gel composition, the gel composition comprising at least one gelling agent, at least one of an alkaloid compound and a cannabinoid compound, and an aerosol former; a nozzle element (42); and an intermediate hollow section (50) between the aerosol-generating substrate bar (12) and the nozzle element (42), the intermediate hollow section (50) comprising: a support member (22) downstream of the aerosol-generating substrate bar (12), the support member (22) comprising a first hollow tubular segment (26) defining a longitudinal cavity (28) providing an unrestricted flow channel, the first hollow tubular segment (26) having a wall thickness of at least 1 millimeter; and an aerosol cooling element (24) in axial alignment with the nozzle element (42) and abutting the upstream end of the nozzle element (42), the aerosol cooling element (24) comprising a second hollow tubular segment (34) having a length of less than 10 millimeters and an internal diameter of at least 2 millimeters, the second hollow tubular segment (34) defining a longitudinal cavity (36) providing an unrestricted flow channel, wherein the flow channel is empty. 2. An aerosol-generating article (10) according to claim 1, wherein the aerosol-generating substrate rod (12) comprises a plug of a porous medium loaded with the gel composition. 3. An aerosol-generating article (10) according to claim 2, wherein the porous medium is in the form of a curled sheet. 4. An aerosol-generating article (10) according to claim 2 or 3, wherein the porous medium comprises cotton fibers. 5. An aerosol-generating article (10) according to any one of claims 2 to 4, wherein the plug of porous medium loaded with the gel composition is circumscribed by a water-repellent envelope. 6. An aerosol-generating article (10) according to any preceding claim, wherein the gel composition comprises at least 1 percent by weight of nicotine. 7. An aerosol-generating article (10) according to any preceding claim, wherein the gel composition further comprises an acid. 8. An aerosol-generating article (10) according to any preceding claim, wherein the gel composition comprises between 1 weight percent and 6 weight percent of the at least one gelling agent. 9. An aerosol-generating article (10) according to any preceding claim, further comprising an elongated susceptor element (44) extending in a longitudinal direction through the aerosol-generating substrate bar (12). 10. An aerosol-generating article (10) according to any preceding claim, wherein the length of the nozzle element (42) is at least 10 millimeters. 11. An aerosol generating article (10) according to any preceding claim, wherein the length of the nozzle element (42) is at least 2 millimeters greater than the length of the aerosol cooling element (24). 12. An aerosol generating article (10) according to any preceding claim, wherein the hollow tubular segment (36) of the aerosol cooling element (24) has a wall thickness of less than 2.5 millimeters. 13. An aerosol-generating article (10) according to any preceding claim, wherein the nozzle element (42) comprises a nozzle filter segment that is formed of a fibrous filtration material, the nozzle filter segment having a length of at least 10 millimeters. 14. An aerosol-generating article (10) according to any preceding claim, further comprising an upstream element (46) provided upstream of the aerosol-generating substrate bar (12).