JP2020114205A - Aerosol-generating article with ventilated hollow segment - Google Patents

Abstract

To provide an aerosol-generating article that enables the provision of a consistently satisfactory aerosol delivery to a consumer during use.SOLUTION: An aerosol-generating article 10 comprises: a rod 12 of an aerosol-generating substrate; a mouthpiece segment 18 comprising a plug of filtration material; and a hollow tubular segment 16 between the rod 12 and the mouthpiece segment 18. The hollow tube segment 16 is longitudinally aligned with the rod 12 and the mouthpiece segment 18, and defines a cavity extending all the way to an upstream end of the mouthpiece segment 18. The article 10 further comprises a ventilation zone 26 at a location along the hollow tubular segment. An equivalent internal diameter of the hollow tubular segment 16 at the location of the ventilation zone 26 is at least about 5 millimeters. The rod 12 of the aerosol-generating substrate comprises at least an aerosol former, the rod having an aerosol former content of at least about 10 percent on a dry weight basis.SELECTED DRAWING: Figure 1

Description

The present invention relates to an aerosol generating article that comprises an aerosol generating substrate that is adapted to generate an inhalable aerosol when heated.

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

Numerous prior art documents disclose aerosol generating devices for consuming aerosol generating articles. For example, such devices include electrically heated aerosol generating devices in which aerosol is generated by heat transfer from one or more electric heating elements of the aerosol generating device to an aerosol-forming substrate of a heated aerosol generating article.

Substrates for heated aerosol generating articles have heretofore generally been manufactured using randomly oriented pieces, strands, or strips of tobacco material. Alternatively, rods for heated aerosol generating articles formed from an assembly of sheets of tobacco material have been proposed, for example in International Patent Application WO-A-2012/164009. The rod disclosed in WO2012/1640099 has a longitudinal porosity that allows air to be drawn through the rod. In effect, the folds in the collection of sheets of tobacco material define longitudinal channels through the rod.

An alternative rod for heated aerosol generating articles is known from international patent application WO-A-2011/101164. These rods are formed from a strand of homogenized tobacco material and cast, rolled, calendered, or extruded a mixture containing particulate tobacco and at least one aerosol former to form a sheet of homogenized tobacco material. Can be formed by Also, in an alternative embodiment, the rod of WO-A-2011/101164 extrudes a mixture comprising particulate tobacco and at least one aerosol former to provide a continuous length of homogenized tobacco material. It may be formed from a strand of homogenized tobacco material obtained by forming.

Substrates for heated aerosol generating articles are usually aerosol formers, i.e. compounds or compounds that promote the formation of an aerosol during use and are substantially resistant to thermal decomposition at the temperature of use of the aerosol generating article. And a mixture of Examples of suitable aerosol formers include polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3-butanediol and glycerin), esters of polyhydric alcohols (such as glycerol mono-, di- or triacetate), and Mention may be made of aliphatic esters of mono-, di- or polycarboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate.

It is also common to include in the aerosol-generating article one or more additional elements that are assembled with the substrate in the same wrapper to produce an inhalable aerosol upon heating. Examples of such additional elements include mouthpiece filtration segments, support elements adapted to provide structural strength to the aerosol-generating article, adapted to favor cooling of the aerosol before reaching the mouthpiece. Cooling elements, etc. are included. However, the inclusion of these additional elements, while proposed for their beneficial effects, generally complicates the overall structure of the aerosol-generating article, making it more complex and expensive to manufacture. In practice, the manufacture of such multi-element aerosol generating articles generally requires more complex manufacturing machines and machine combinations.

From this point, aerosol generating articles having a simpler structure have been proposed. However, in the absence of certain additional components, such as, for example, an aerosol cooling element, it can be more difficult to produce an aerosol-generating article that consistently provides a satisfactory aerosol delivery and RTD to the consumer.

Therefore, it is desirable to provide an aerosol-generating article that allows a consumer to consistently provide a satisfactory aerosol delivery during use. Further, it would be desirable to provide improved aerosol generating articles having such satisfactory RTD values. It would likewise be desirable to provide such an aerosol-generating article that is efficiently and rapidly manufactured and preferably has low RTD variation between articles. The present invention aims to provide a technical solution adapted to achieve at least one of the desired results mentioned above.

According to one aspect of 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 and a mouthpiece segment that includes a plug of filtration material, is located downstream of the rod and is longitudinally aligned with the first segment, and at a position between the rod and the mouthpiece segment. A hollow tubular segment. The hollow tube segment is longitudinally aligned with the rod and mouthpiece segment. Further, the hollow tubular segment defines a recess that extends entirely to the upstream end of the mouthpiece segment. The aerosol-generating article further comprises a ventilation zone at a location along the hollow tubular segment. The equivalent inner diameter of the hollow tubular segment at the location of the ventilation zone is at least about 5 millimeters. The rod of the aerosol-generating substrate comprises at least an aerosol former, and the rod of the aerosol-generating substrate has an aerosol former content of at least about 10 percent by dry weight.

The term “aerosol generating article” as used herein means an article in which an aerosol generating substrate is heated to produce an inhalable aerosol for delivery to a consumer. As used herein, the term "aerosol-generating substrate" means a substrate that has the ability to release volatile compounds upon heating to produce an aerosol.

Traditional cigarettes are ignited when the user applies a flame to one end of the cigarette and inhales air through the other end. The localized heat provided by the flame and oxygen in the air drawn through the cigarette ignites the ends of the cigarette and the resulting combustion produces inhalable smoke. In contrast, in a heated aerosol generating article, the aerosol is produced by heating a flavor generating substrate (such as tobacco). Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles, and aerosol generation in which the aerosol is produced by transfer of heat from a combustible fuel element or heat source to a physically separated aerosol-forming material. Examples include articles. For example, the aerosol-generating article according to the invention has particular application as an aerosol-generating system comprising an electrically heated aerosol-generating device having an internal heater blade adapted to be inserted into a rod of an aerosol-generating substrate. Aerosol-generating articles of this type are described in the prior art, for example in EP 0822670.

As used herein, the term "aerosol generating device" means a device comprising a heater that interacts with an aerosol generating substrate of an aerosol generating article to generate an aerosol.

The term "tubular segment" is used herein to mean an elongate element that defines a lumen or airflow passageway along its longitudinal axis. In particular, the term "tubular" in the following has at least one air flow conduit having a substantially cylindrical cross section and establishing unbroken fluid communication between the upstream end of the tubular element and the downstream end of the tubular element. Used for the tubular element. However, it will be appreciated that alternative geometries of the cross-section of the tubular element may be possible.

As used herein, the term "longitudinal direction" refers to the direction that extends between the upstream and downstream ends of an aerosol-generating article and that corresponds to the major longitudinal axis of the aerosol-generating article. As used herein, the terms "upstream" and "downstream" refer to the relative position of an element (or portion of an element) of an aerosol-generating article relative to the direction in which the aerosol is delivered through the aerosol-generating article during use. Describe.

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

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

The term "peripheral wall thickness of the tubular element" is used herein to mean the minimum distance measured between the outer and inner surfaces of the wall that bounds the perimeter of the tubular element. In practice, the distance at a given location is measured along a direction that is locally substantially perpendicular to the outer and inner surfaces of the tubular element. For tubular elements having a substantially circular cross-section, the distance is measured substantially along the radial direction of the tubular element.

In some embodiments, the thickness of the peripheral wall of the tubular element is constant. In an alternative embodiment, the thickness of the peripheral wall of the tubular element varies along the length of the tubular element. This may be because the tubular element is formed from a material that has an irregular surface finish (eg, the tubular element is provided in the form of a cellulose acetate tube). Alternatively, this may be because the tubular element is designed to include tapered sections or the like. In embodiments where the thickness of the peripheral wall of the tubular element varies along the length of the tubular element, "the thickness of the peripheral wall of the tubular element" means the outer surface of the wall at different locations along the length of the tubular element. Is taken as the average value calculated on the basis of several values measured as the minimum distance between the inner surface and the inner surface.

In either embodiment, a particularly significant parameter is the thickness of the peripheral wall of the tubular element at the location of the ventilation zone.

The expression "impermeable material" is used throughout this specification to mean a material that does not allow the passage of fluids, especially air and smoke, through the interstices or pores of the material. When the hollow tubular segment is formed of a material impermeable to air and aerosol particles, the air and aerosol particles drawn through the hollow tubular segment are forced to be internally defined by the hollow tubular segment. Flow through the airflow conduit but not across the peripheral wall of the hollow tubular segment.

As used herein, the term "homogenized tobacco material" includes any tobacco material formed by agglomeration of particles of tobacco material. Sheets or webs of homogenized tobacco material are formed by grinding one or both of tobacco leaf lamina and tobacco leaf stems, or by agglomerating particulate tobacco obtained by other methods of pulverization. To be done. In addition, the homogenized tobacco material may include one or more of the small amount of tobacco dust, tobacco fines, and other particulate tobacco by-products formed during tobacco processing, handling, and shipping. The homogenized sheet of tobacco material may be produced by a casting, extrusion, papermaking process, or any other suitable process known in the art.

The term “porous” as used herein refers to a material that provides a plurality of pores or openings that allow the passage of air through the material.

The term "ventilation level" is used throughout this specification to mean the volume ratio of the airflow entering the aerosol-generating article through the ventilation zone (airflow) to the sum of the aerosol airflow and the airflow. used. The higher the aeration level, the higher the dilution of the aerosol stream delivered to the consumer.

As briefly mentioned above, the aerosol-generating article of the present invention comprises an aerosol-generating substrate rod, a mouthpiece segment containing a plug of filtration material, and a hollow tubular segment located between the rod and the mouthpiece segment. Prepare These three elements are longitudinally aligned. The rod of the aerosol-generating substrate comprises at least one aerosol former.

In contrast to known aerosol-generating articles, the rods of aerosol-generating substrates have an aerosol former content of at least about 10 percent on a dry weight basis. Further, the hollow tubular segment defines a recess that extends entirely to the upstream end of the mouthpiece segment, and a vent zone is provided at a location along the hollow tubular segment. Further, the equivalent inner diameter of the hollow tube segment is at least about 5 millimeters.

The hollow tubular element defining a recess extending generally to the upstream end of the mouthpiece segment provides an aerosol-generating article disposed between the rod of the aerosol-generating substrate and the mouthpiece, thereby providing the overall structure of the article. Complexity can be significantly reduced compared to existing aerosol generating articles. This advantageously simplifies the manufacturing process and reduces the complexity of manufacturing and the equipment required to carry out the manufacturing process.

One such aerosol-generating article is adapted to reduce the temperature of the aerosol stream withdrawn through the aerosol-generating article, as is the case, for example, with the aerosol-generating articles described in International Patent Application WO 2013/120565. It does not necessarily have an aerosol cooling element.

The inventors have found that satisfactory cooling of the flow of aerosol produced during heating of an article and drawn through a hollow tubular element is achieved by providing a ventilation zone at a location along the hollow tubular segment. Found. In addition, surprisingly, the inventor utilizes a hollow tubular segment having an equivalent inner diameter of at least about 5 millimeters to offset the effects of increased aerosol dilution that results from introducing circulating air into the article. It has been found possible.

Without wishing to be bound by theory, as the aerosol moves toward the mouthpiece segment, the introduction of the circulating air causes a rapid reduction in the temperature of the aerosol stream, which causes the circulating air to reach the upstream end of the tubular segment. Entering the aerosol stream relatively close to (i.e., sufficiently close to the heat source and the rod of the aerosol generating substrate) that dramatic cooling of the aerosol stream is achieved, which has a beneficial effect on condensation and nucleation of aerosol particles. Considered to have. Thus, the overall ratio of aerosol particle phase to aerosol gas phase may be improved compared to existing non-breathable aerosol generating articles.

At the same time, by utilizing a hollow tubular element having an equivalent inner diameter of 5 mm or more, the aerosol is available to initiate the nucleation process as soon as the aerosol component leaves the rod of the aerosol-generating substrate. This ensures that the overall internal volume of the tubular element and the cross-sectional surface area of the hollow tubular segment are effectively maximized while at the same time the hollow tubular segment prevents collapse of the aerosol-generating article. This in turn ensures that it has the structural strength necessary to provide some support for the rod of the aerosol-generating substrate, and that the RTD of the hollow tubular segment is minimized. It is understood that the large value of the cross-sectional surface area of the hollow tubular segment depressions is associated with a reduced velocity of the aerosol flow traveling along the aerosol-generating article and, in addition, favors nucleation. In fact, without being bound by theory, as in the case of the article according to the invention, by providing a depression with such a large volume, inside it, the nucleation phenomenon is slowed down by slowing the flow of the aerosol stream. The improved reduction effectively provides a cooling chamber that can favor the condensation of aerosol particles upstream of the mouth end of the article.

It will be appreciated that providing a sufficiently wide tubular depression downstream of the rod of the aerosol-generating substrate will favor a sufficient amount of aerosol formation during use. As a result, a greater proportion of the aerosol particles produced begin to condense before reaching the mouth end of the article.

In fact, surprisingly, the inventors have discovered how the beneficial effect of enhanced nucleation is diluted so that satisfactory values of aerosol delivery are consistently achieved with aerosol-generating articles according to the invention. It was found to significantly offset the undesired effects of. This is because the rod length of the aerosol-generating substrate is less than about 40 millimeters, preferably less than 25 millimeters, and even more preferably less than 20 millimeters, or the total length of the aerosol-generating article is less than about 70 millimeters, preferably about 60 millimeters. Particularly advantageous for "short" aerosol-generating articles, such as those less than millimeters, and even more preferably less than 50 millimeters. As will be appreciated, such aerosol generating articles have less time and space for aerosol formation and for the particulate phase of the aerosol to be available for delivery to the consumer.

Furthermore, since the hollow tubular element does not substantially contribute to the RTD of the aerosol-generating article, in the aerosol-generating article according to the invention, the length and density of the rod of the aerosol-generating substrate or the length of the segment of the filter material of the mouthpiece. Adjusting the depth and density can advantageously fine tune the overall RTD of the article. This allows consistent and very accurate manufacture of aerosol-generating substrates with a given RTD, so that a satisfactory level of RTD can be provided to the consumer even in the presence of ventilation. ..

The aerosol-generating article according to the invention can be manufactured in a continuous process, which can be carried out at high speed and efficiently, without the need for extensive modifications of the manufacturing equipment, existing production lines for the production of heated aerosol-generating articles. Can be easily manufactured.

The rod of the aerosol-generating substrate preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article.

The aerosol-generating substrate rods preferably have an outer diameter of at least 5 millimeters. The rod of the aerosol-generating substrate may have an outer diameter of about 5 millimeters to about 12 millimeters, such as about 5 millimeters to about 10 millimeters, or about 6 millimeters to about 8 millimeters. In one preferred embodiment, the rod of the aerosol-generating substrate has an outer diameter of 7.2 millimeters ±10 percent.

The rod of the aerosol-generating substrate may have a length of about 5 millimeters to about 100 mm. The rod of the aerosol-generating substrate preferably has a length of at least about 5 millimeters, more preferably at least about 7 millimeters. Additionally or alternatively, the rod of the aerosol-generating substrate preferably has a length of less than about 80 millimeters, more preferably less than about 65 millimeters, and less than about 50 millimeters. It is even more preferable to have In a particularly preferred embodiment, the rod of the aerosol-generating substrate has a length of less than about 35 millimeters, more preferably less than 25 millimeters, even more preferably less than about 20 millimeters. preferable. In one embodiment, the rod of the aerosol-generating substrate may have a length of about 10 millimeters. In a preferred embodiment, the rod of the aerosol-generating substrate has a length of about 12 millimeters.

The rod of the aerosol-generating substrate preferably has a substantially uniform cross section along the length of the rod. It is especially preferred that the rod of the aerosol-generating substrate has a substantially circular cross section.

In a preferred embodiment, the aerosol-forming substrate comprises an assembly of one or more crimped sheets of homogenized tobacco material. The one or more sheets of homogenized tobacco material are preferably textured. As used herein, the term "textured sheet" means a sheet that has been crimped, embossed, debossed, perforated, or otherwise deformed. Textured sheets of homogenized tobacco material for use in the present invention may include a plurality of spaced indentations, protrusions, perforations or combinations thereof. According to a particularly preferred embodiment of the invention, the rod of the aerosol-generating substrate comprises an assembly of crimped sheets of homogenized tobacco material surrounded by a wrapper.

The term "crimped sheet", as used herein, is intended to be substantially synonymous with the term "crimped sheet" and includes a plurality of substantially parallel raised or corrugated shapes. Means a sheet with The crimped sheet of homogenized tobacco material preferably has a plurality of raised or corrugated shapes substantially parallel to the cylindrical axis of the rod according to the invention. This conveniently facilitates the assembly of crimped sheets of homogenized tobacco material to form rods. However, it should be appreciated that crimped sheets of homogenized tobacco material for use in the present invention may alternatively or additionally include a plurality of acute or obtuse angles with respect to the cylindrical axis of the rod. Has substantially parallel ridges or corrugations. In certain embodiments, a homogenized sheet of tobacco material for use in a rod of an article of the invention can be textured substantially evenly over its entire surface. For example, a crimped sheet of homogenized tobacco material for use in making a rod for use in an aerosol generating article according to the present invention comprises a plurality of substantially crimped sheets substantially uniformly spaced across the width of the sheet. May include parallel ridges or corrugations.

A sheet or web of homogenized tobacco material for use in the present invention may have a tobacco content of at least about 40 weight percent dry weight and a tobacco content of at least about 60 weight percent dry weight. More preferably it has a content, more preferably it has a tobacco content of at least about 70 weight percent on a dry weight basis, and most preferably it has a tobacco content of at least about 90 weight percent on a dry weight basis.

A sheet or web of homogenized tobacco material for use in an aerosol-generating substrate is one or more unique binders that are endogenous tobacco binders to help agglomerate particulate tobacco. It may include one or more exogenous binders that are tobacco exogenous binders, or a combination thereof. Alternatively or in addition, sheets of homogenized tobacco material for use in aerosol-generating substrates include tobacco and non-tobacco fibers, aerosol formers, wetting agents, plasticizers, flavoring agents, fillers, aqueous agents. And other additives, including but not limited to non-aqueous solvents and combinations thereof.

Suitable exogenous binders for inclusion bodies in sheets or webs of homogenized tobacco material for use in aerosol-generating substrates are well known in the art and include gums such as guar gum, xanthan gum, gum arabic and locust. Conjugation of cellulose binders such as bean gum, such as hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose and ethyl cellulose, polysaccharides such as starch, organic acids such as alginic acid, sodium alginate, agar and pectin. Includes, but is not limited to, base salts and the like, and combinations thereof.

Suitable non-tobacco fibers for inclusion in a sheet or web of homogenized tobacco material for use in an aerosol-generating substrate are well known in the art and include cellulosic fibers, soft wood fibers, hard wood fibers, jute fibers and the like. But not limited thereto. Prior to inclusion in a sheet of homogenized tobacco material for use in an aerosol generating substrate, the non-tobacco fibers may be treated by any suitable process known in the art, including mechanical pulping; refining; Includes, but is not limited to, chemical pulping; bleaching; sulfate pulping; and combinations thereof.

The sheet or web of homogenized tobacco material preferably comprises an aerosol former. As used herein, the term "aerosol former", in use, facilitates the formation of an aerosol and is substantially any suitable material that is resistant to thermal decomposition at the temperature of use of the aerosol-generating article. A known compound or mixture of compounds is described.

Suitable aerosol formers are known in the art: polyhydric alcohols such as propylene glycol, triethylene glycol, 1,3-butylene glycol and glycerin; polyhydric alcohols such as glycerol mono-, di- or triacetate. Esters; and aliphatic esters of mono-, di- or polycarboxylic acids such as dimethyldodecanedioate and dimethyltetradecanedioate, but are not limited thereto.

Preferred aerosol formers are polyhydric alcohols such as propylene glycol, triethylene glycol, 1,3-butanediol and most preferably glycerin or mixtures thereof.

The sheet or web of homogenized tobacco material may include a single aerosol former. Alternatively, the homogenized sheet or web of tobacco material may comprise a combination of two or more aerosol formers.

The sheet or web of homogenized tobacco material has an aerosol former content of greater than 10 percent on a dry weight basis. The sheet or web of homogenized tobacco material preferably has an aerosol former content of greater than 12 percent on a dry weight basis. More preferably, the homogenized tobacco material sheet or web has an aerosol former content of greater than 14 percent on a dry weight basis. Even more preferably, the homogenized sheet or web of tobacco material has an aerosol former content of greater than 16 percent on a dry weight basis.

The homogenized sheet of tobacco material may have an aerosol former content of from about 10 percent to about 30 percent on a dry weight basis. The sheet or web of homogenized tobacco material preferably has an aerosol former content of less than 25 percent on a dry weight basis.

In a preferred embodiment, the homogenized sheet of tobacco material has an aerosol former content of approximately 20 percent by dry weight.

Homogenized tobacco sheets or webs for use in the aerosol-generating articles of the present invention may be made by methods well known in the art, such as those disclosed in International Patent Application No. WO2012/164090A2. .. In a preferred embodiment, a sheet of homogenized tobacco material for use in an aerosol generating article is formed from a slurry containing particulate tobacco, guar gum, cellulosic fibers and glycerin by a casting process.

Alternative arrangements of homogenized tobacco material in rods for use in aerosol-generating articles are well known to those of skill in the art and include multiple stacked sheets of homogenized tobacco material, longitudinal axis of It may include a plurality of elongate tubular elements or the like formed around wound strips of homogenized tobacco material.

As a further alternative, the rod of the aerosol-generating substrate may comprise a non-tobacco-based nicotine-containing material, such as a sheet of absorbent non-tobacco material incorporating nicotine (eg, in the form of a nicotine salt) and an aerosol former. Examples of such rods are described in International Application WO-A-2015/052652. Additionally or alternatively, the rod of the aerosol-generating substrate may include non-tobacco plant material, such as aromatic non-tobacco plant material.

In the rod of the aerosol-generating substrate of the article according to the invention, the aerosol-generating substrate is preferably surrounded by a wrapper. The wrapper can be formed of a porous or non-porous sheet material. The wrapper can be formed of any suitable material or combination of materials. The wrapper is preferably a paper wrapper.

The mouthpiece segment includes a plug of filter material that can remove particulate components, gaseous components, or a combination. Suitable filter materials are well known in the art and include, for example, fibrous filter materials such as cellulose acetate tow, viscose fibers, polyhydroxyalkanoic acid (PHA) fibers, polylactic acid (PLA) fibers and papers such as activated. Including, but not limited to, adsorbents such as alumina, zeolites, molecular sieves and silica gel, and combinations thereof. Additionally, the plug of filtration material may further include one or more aerosol modifiers. Suitable aerosol modifiers are well known in the art and include, but are not limited to, flavoring agents such as menthol. In some embodiments, the mouthpiece can further include an indentation on the oral end downstream of the plug of filtration material. As an example, the mouthpiece may include a hollow tube longitudinally aligned with the plug of filtration material and located immediately downstream of the plug of filtration material, the hollow tube at the downstream end of the mouthpiece. Form a recess at the mouth end that is open to the outside environment.

The length of the mouthpiece is preferably at least about 4 millimeters, more preferably at least about 6 millimeters, and even more preferably at least about 8 millimeters. Additionally or alternatively, the length of the mouthpiece is preferably less than 25 millimeters, more preferably less than 20 millimeters, even more preferably less than 15 millimeters. In some preferred embodiments, the length of the mouthpiece is about 4 millimeters to about 25 millimeters, more preferably about 6 millimeters to about 20 millimeters. In the exemplary embodiment, the length of the mouthpiece is about 7 millimeters. In another exemplary embodiment, the mouthpiece is about 12 millimeters in length.

The hollow tubular segment is preferably an annular tube that partitions and defines an air gap within the aerosol generating article. In effect, the hollow tubular segment provides a chamber in which the volatilized aerosol components released upon heating of the aerosol-generating substrate accumulate and flow therein. As briefly mentioned above, this chamber extends generally longitudinally to the upstream end of the mouthpiece. This means that no intermediate element is provided between the hollow tubular segment and the mouthpiece, and when the aerosol flowing through the aerosol-generating article reaches the downstream end of the hollow tubular segment, it passes through the aerosol-generating article. It means that the flowing aerosol substantially reaches the upstream end of the mouthpiece. More specifically, the aerosol flowing through the aerosol-generating article generally reaches the upstream end of a segment of the mouthpiece filtration material.

Thus, in the aerosol-generating article according to the invention, the hollow tubular segment maintains the rod of the aerosol-generating substrate at a predetermined distance from the mouthpiece and provides an elongated airflow conduit that forms the aerosol and flows toward the mouthpiece. .. During use, a thermal gradient is established along this airflow conduit. In practice, the temperature difference is such that the temperature of the volatilized aerosol component that enters the hollow tubular segment at the upstream end is that of the volatilized aerosol component that exits the hollow tubular segment at the downstream end (ie, the upstream end of the mouthpiece). Provided to be greater than temperature.

On the other hand, the hollow tubular segment must withstand any axial compressive loads or bending moments that may be applied to the hollow tubular segment during manufacture of the aerosol-generating article. Moreover, the hollow tubular segment should provide structural strength to the aerosol-generating article so that it can be easily handled by the consumer and inserted into the aerosol-generating device for use. On the other hand, it is desirable that the overall volume of the chamber internally defined by the hollow tubular element be as large as possible, in order to favor the formation of the aerosol and to improve the delivery of the aerosol to the consumer.

To meet these requirements, the hollow tube segment has an equivalent inner diameter of at least about 5 millimeters, as briefly described above. The term “equivalent inner diameter” as used herein means the diameter of a circle having the same surface area as the cross section of an airflow conduit defined internally by a hollow tubular segment. The cross section of the airflow conduit can have any suitable shape. However, as briefly mentioned above, circular cross-sections are preferred, ie the hollow tubular segment is a substantially cylindrical tube. In that case, the equivalent inner diameter of the hollow tubular segment corresponds to the inner diameter of the virtually cylindrical tube.

More preferably, the hollow tubular segment has an equivalent inner diameter of at least about 5.25 millimeters, and even more preferably at least about 5.5 millimeters. In some embodiments, the hollow tubular segment has an equivalent inner diameter of at least about 6 millimeters, or at least about 6.5 millimeters, or at least about 7 millimeters.

Furthermore, the hollow tubular segment preferably has an equivalent inner diameter of less than about 10 millimeters. More preferably, the hollow tubular segment has an equivalent inner diameter of less than about 9.5 millimeters, and even more preferably less than 9 millimeters.

The equivalent inner diameter of the hollow tubular segment is measured at the location of the ventilation zone.

In a preferred embodiment, the equivalent inner diameter of the hollow tubular segment is substantially constant along the length of the hollow tubular segment. In other embodiments, the equivalent inner diameter of the hollow tubular segment can vary along the length of the hollow tubular segment.

Surprisingly, the inventors have found that an aerosol-generating article according to the invention comprising a hollow tubular segment comprising a hollow tubular segment having an equivalent inner diameter within the above-mentioned range can provide particularly satisfactory aerosol delivery values. Found. Without wishing to be bound by theory, an aerosol stream flowing along a hollow tubular segment having an equivalent inner diameter within the above range is such that an incoming cooler stream of circulating air is received by the aerosol stream, It is believed that when mixed, it will flow relatively slowly. Since the aerosol stream travels relatively slowly along the hollow tubular segment, it is expected that the beneficial cooling effects on aerosol nucleation under these conditions will be maximized.

The equivalent inner diameter of the hollow tubular segment is preferably substantially constant along the length of the hollow tubular segment. However, in some embodiments, the cross-sectional surface area of the hollow tubular segment can vary along the length of the hollow tubular segment. In such an embodiment, the equivalent inner diameter is measured at the location of the ventilation zone.

In a preferred embodiment, the peripheral wall thickness of the hollow tubular segment is less than 1.5 millimeters. More preferably, the peripheral wall thickness of the hollow tubular segment is less than 1250 micrometers, even more preferably less than 1000 micrometers, and most preferably less than 900 micrometers. In a particularly preferred embodiment, the peripheral wall thickness of the hollow tubular segment is less than 800 micrometers.

Additionally or alternatively, the peripheral wall thickness of the hollow tubular segment is at least about 100 micrometers. The peripheral wall thickness of the hollow tubular segment is preferably at least about 200 micrometers.

Without wishing to be bound by theory, by utilizing a hollow tubular segment having a peripheral wall whose thickness is within the above-mentioned range, it is advantageous to prior to its contact and mixing with the stream of aerosol. , It seems possible to limit or even substantially prevent the diffusion of circulating air. It is further understood that this favors the nucleation phenomenon. In fact, it is possible to improve the effect of cooling on the formation of new aerosol particles by providing more controllable localized cooling of the flow of volatilized species drawn through the hollow tubular segment. ..

As briefly described above, the aerosol-generating article according to the present invention comprises a ventilation zone at a location along the hollow tubular segment. The ventilation zone is preferably provided less than about 18 millimeters from the upstream end of the hollow tubular segment. The distance between the ventilation zone and the upstream end of the hollow tubular segment is preferably less than about 15 millimeters. Even more preferably, the distance between the ventilation zone and the upstream end of the hollow tubular segment is less than about 10 millimeters.

Additionally or alternatively, the distance between the ventilation zone and the upstream end of the hollow tubular segment is preferably at least 2 millimeters. More preferably, the distance between the ventilation zone and the upstream end of the hollow tubular segment is at least about 4 millimeters. Even more preferably, the distance between the ventilation zone and the upstream end of the hollow tubular segment is at least about 6 millimeters.

A ventilation zone is preferably provided along the hollow tubular segment at least 2 millimeters from the upstream end of the mouthpiece. A ventilation zone is preferably provided along the hollow tubular segment at least 4 millimeters from the upstream end of the mouthpiece. Even more preferably, the ventilation zone is provided along the hollow tubular segment at least 6 millimeters from the upstream end of the mouthpiece.

When the mixture of air and aerosol particles flowing through the aerosol-generating article reaches the ventilation zone, the ambient air drawn through the ventilation zone into the hollow tubular segment mixes with the aerosol. This causes the temperature of the aerosol mixture to decrease rapidly while partially diluting the mixture of air and aerosol particles. As described in more detail below, by providing a ventilation zone at a distance from the upstream end of the mouthpiece segment that is within the ranges described above, effectively providing a cooling chamber just upstream of the mouthpiece, where Can favor nucleation and aerosol particle growth. In this way, the dilution effects of the circulating air entering the hollow tubular segment are at least partially offset, which advantageously allows the consumer to provide a satisfactory aerosol delivery level.

In some embodiments, the ratio of the distance between the ventilation zone and the upstream end of the hollow tubular segment to the equivalent inner diameter of the hollow tubular segment at the location of the ventilation zone is less than 4. The ratio of the distance between the ventilation zone and the upstream end of the hollow tubular segment to the equivalent inner diameter of the hollow tubular segment at the location of the ventilation zone is preferably less than 3.5. More preferably, the ratio of the distance between the ventilation zone and the upstream end of the hollow tubular segment to the equivalent inner diameter of the hollow tubular segment at the location of the ventilation zone is less than 3. Even more preferably, the ratio of the distance between the ventilation zone and the upstream end of the hollow tubular segment to the equivalent inner diameter of the hollow tubular segment at the location of the ventilation zone is less than 2.5.

In a particularly preferred embodiment, the ratio of the distance between the ventilation zone and the upstream end of the hollow tubular segment to the equivalent inner diameter of the hollow tubular segment at the location of the ventilation zone is less than 2 and less than 1.5. More preferably, it is even more preferably less than 1.2.

A ventilation zone is preferably provided along the hollow tubular segment at least 10 millimeters from the downstream end of the mouthpiece segment. More preferably, the ventilation zone is provided along the hollow tubular segment at least 12 millimeters from the downstream end of the mouthpiece segment. Even more preferably, the ventilation zone is provided along the hollow tubular segment at least 15 millimeters from the downstream end of the mouthpiece segment. This is advantageous in ensuring that during use the ventilation zone is not blocked by the consumer's lips.

Additionally or alternatively, the ventilation zone is preferably located along the hollow tubular segment less than 25 millimeters from the downstream end of the mouthpiece segment. More preferably, the ventilation zone is less than 20 millimeters along the hollow tubular segment from the downstream end of the mouthpiece segment. This advantageously allows, in use, cold ambient air to be easily drawn into the hollow tubular segment when the aerosol-generating article is received in the heating chamber of an electrically heated aerosol generator. Ensure that the venting zone is effectively in position along the hollow tubular segment protruding outside the heating chamber.

In some preferred embodiments, the ventilation zone is about 10 millimeters to about 25 millimeters from the downstream end of the mouthpiece segment along the hollow tubular segment, more preferably about 12 millimeters to about 25 millimeters from the downstream end of the mouthpiece segment. Offered in the 20 mm position. In an exemplary embodiment, a ventilation zone is provided along the hollow tubular segment, 18 millimeters from the downstream end of the mouthpiece segment. In another exemplary embodiment, a ventilation zone is provided along the hollow tubular segment, 13 millimeters from the downstream end of the mouthpiece segment.

Aerosol-generating articles typically can have a ventilation level of at least about 10 percent, preferably at least about 20 percent.

In a preferred embodiment, the aerosol-generating article has a ventilation level of at least about 30 percent. More preferably, the aerosol-generating article has a ventilation level of at least about 35 percent. Additionally or alternatively, the aerosol-generating article preferably has a ventilation level of less than about 60 percent. More preferably, the aerosol-generating article has a ventilation level of less than about 50 percent. In a particularly preferred embodiment, the aerosol-generating article has a ventilation level of about 30 percent to about 60 percent. More preferably, the aerosol-generating article has a ventilation level of from about 35 percent to about 50 percent. In some particularly preferred embodiments, the aerosol-generating article has a ventilation level of about 40 percent.

Without wishing to be bound by theory, the inventor has found that the temperature drop caused by introducing cooler ambient air through the ventilation zone into the hollow tubular segment favors the nucleation and growth of aerosol particles. It has been found that it can have an effect.

The formation of aerosols from gaseous mixtures containing various species relies on delicate interactions between nucleation, evaporation, and condensation and fusion accounting for changes in vapor concentration, temperature and velocity fields. So-called conventional nucleation theory is based on the assumption that some of the molecules in the gas phase are large enough to remain coherent for a long time with sufficient probability (eg, 1/2 probability). There is. These molecules represent a class of critical, threshold molecular clusters in transient molecular aggregates, with smaller molecular clusters generally more likely to decompose into the gas phase more rapidly, and larger clusters generally growing. It means easy to do. These critical clusters are identified as the major nucleation cores where droplets are expected to grow due to condensation of molecules from the vapor. It is envisaged that freshly nucleated untreated droplets will appear with a particular original diameter and then grow by some size. This can be facilitated and enhanced by the rapid cooling of the surrounding vapor, which induces condensation. In this regard, it is helpful to keep in mind that evaporation and condensation are one and the same mechanism, namely the two sides of mass transfer of gas and liquid. Evaporation is associated with the net mass transfer from the droplet to the gas phase, and condensation is the net mass transfer from the gas phase to the droplet phase. Evaporation (or condensation) causes the droplets to shrink (or grow), but the number of droplets does not change.

In this scenario, the temperature and rate of cooling can play an important role in determining how the system responds, although the fusion phenomenon may add complexity. In general, different cooling rates can lead to significantly different temperature behavior with respect to the formation of the liquid phase (droplets) because the nucleation process is generally non-linear. Without wishing to be bound by theory, it is postulated that cooling causes a sharp increase in the number of droplet condensations, after which this growth can be strongly increased in the short term (burst nucleation). This burst nucleation appears to be more significant at low temperatures. Furthermore, high cooling rates could favor the onset of premature nucleation. In contrast, reducing the cooling rate appears to have a beneficial effect on the final size that the aerosol droplets eventually reach.

Therefore, rapid cooling induced by introducing ambient air into the hollow tubular segment through the ventilation zone can be advantageously used to favor the nucleation and growth of aerosol droplets. However, at the same time, admitting ambient air into the hollow tubular segment has the direct drawback of diluting the aerosol stream delivered to the consumer.

Surprisingly, the inventors have found that the dilution effect on aerosols can be evaluated by measuring the effect on the delivery of glycerin contained in the aerosol formers, especially as aerosol formers, at aeration levels of 30% to 50%. It has been found that at some point it is advantageously minimized. In particular, an aeration level of 35 percent to 42 percent was found to lead to particularly satisfactory glycerin delivery values.

Moreover, the inventor has found that in the aerosol-generating article according to the invention, the cooling and dilution effects caused by the circulating air at positions along the conduit defined by the hollow tubular segment described above are surprising for the production and delivery of phenol-containing species. It was found that it has a reducing effect.

The vent zone may include one or more rows of perforations formed through the peripheral wall of the hollow tubular segment. The ventilation zone preferably comprises only one row of perforations. It is understood that this is advantageous in that the nucleation of the aerosol can be further enhanced by condensing the cooling effect provided by the ventilation over the short portion of the depression defined by the hollow tube segment. .. This is because the faster and more dramatic cooling of the stream of volatilized species is expected to be particularly advantageous for the formation of new nuclei of aerosol particles.

The one or more rows of perforations are preferably circumferentially arranged around the wall of the hollow tube. When the ventilation zone comprises two or more rows of perforations formed through the peripheral wall of the hollow tubular segment, the rows are longitudinally spaced from one another along the hollow tubular segment. As an example, adjacent rows of perforations may be longitudinally spaced from each other by a distance of about 0.25 millimeters to 0.75 millimeters.

Preferably, at least one equivalent diameter of the vent holes is at least about 100 micrometers. Preferably, at least one equivalent diameter of the vent perforations is at least about 150 micrometers. Even more preferably, the at least one equivalent diameter of the vent holes is at least about 200 micrometers. Additionally or alternatively, at least one equivalent diameter of the vent perforations is preferably less than about 500 micrometers. More preferably, at least one equivalent diameter of the vent holes is less than about 450 micrometers. Even more preferably, at least one equivalent diameter of the vent holes is less than about 400 micrometers. The term "equivalent diameter", as used herein, means the diameter of a circle having the same surface area as the cross section of the vent perforations. The cross section of the vent perforations can have any suitable shape. However, circular vent perforations are preferred.

The vent holes may be of uniform size. Alternatively, the vent perforations may vary in size. By varying the number and size of the vent holes, it is possible to control the amount of ambient air that enters into the hollow tubular segment when the consumer inhales the mouthpiece of the aerosol-generating article during use. As such, it is advantageously possible to adjust the ventilation level of the aerosol-generating article.

Vent perforation may be accomplished by any suitable technique, such as laser techniques, mechanical perforation of hollow tubular segments as part of an aerosol generating article, or prior to combination with other elements to form an aerosol generating article. It can be formed using pre-drilling of hollow tubular segments. Vent perforations are preferably formed by online laser perforation.

The length of the hollow tubular segment is preferably at least about 10 millimeters. More preferably, the length of the hollow tubular segment is at least about 15 millimeters. Additionally or alternatively, the length of the hollow tubular segment is preferably less than about 30 millimeters. More preferably, the length of the hollow tubular segment is less than about 25 millimeters. Even more preferably, the length of the hollow tubular segment is less than about 20 millimeters. In some preferred embodiments, the length of the hollow tubular segment is from about 10 millimeters to about 30 millimeters, more preferably from about 12 millimeters to about 25 millimeters, and from about 15 millimeters to about 20 millimeters. Is even more preferred. As an example, in a particularly preferred embodiment, the hollow tubular segment has a length of about 18 millimeters. In another particularly preferred embodiment, the hollow tubular segment has a length of about 13 millimeters.

The overall length of the aerosol-generating article according to the present invention is preferably at least about 40 millimeters. Additionally or alternatively, the total length of the aerosol-generating article according to the present invention is preferably less than about 70 millimeters, more preferably less than 60 millimeters, even more preferably less than 50 millimeters. In a preferred embodiment, the total length of the aerosol-generating article is about 40 millimeters to about 70 millimeters. In an exemplary embodiment, the aerosol generating article has a total length of about 45 millimeters.

The hollow tubular segment is preferably formed of a substantially impermeable material. Thus, air and aerosol particles withdrawn through the hollow tubular segment are forced to flow through the hollow tubular segment from its upstream end to its downstream end, but not across the peripheral wall of the hollow tubular element.

In some embodiments, the hollow tubular segment comprises a wrapper and the wrapper surrounds the rod and mouthpiece segment. In practice, a wrapper having a thickness within the above range is used to surround and connect the rod and mouthpiece segment of the aerosol-generating substrate, the wrapper effectively forming the peripheral wall of the hollow tubular element. To do.

As an example, a combination of wrapper and mouthpiece segment connecting such rods can have a basis weight of at least about 70 grams per square meter (gsm). The combination of wrapper and mouthpiece segment connecting such rods preferably has a basis weight of at least about 80 grams/square meter, more preferably at least about 90 grams/square meter. In a particularly preferred embodiment, the rod connecting wrapper and mouthpiece segment combination has a basis weight of at least about 110 grams/square meter, more preferably at least about 130 grams/square meter.

In other embodiments, the hollow tubular segment comprises a tube formed of a polymeric or cellulosic material and the heated aerosol generating article further comprises a wrapper surrounding the rod, tube and mouthpiece segment. By way of example, the cellulosic material may include paper or cardboard or mixtures thereof.

As an example, the hollow tubular segment may include a tube formed from an extruded plastic tube. Alternatively, the hollow tubular segment may include a tube formed from multiple overlapping paper layers, such as multiple parallel wound paper layers or multiple spiral wound paper layers. Forming a tube from multiple overlapping paper layers can help further improve resistance to collapse or deformation. The tube preferably comprises two or more paper layers. Alternatively, or additionally, the tube preferably comprises less than 11 paper layers.

One of these tubes can be impermeable by using a substantially impermeable paper. The term "substantially impermeable paper" as used herein, has an air permeability of less than about 20 Coresta units, more preferably less than about 10 Coresta units, measured according to ISO 2965:2009. Is used to mean a paper having an air permeability, most preferably less than about 5 Coresta units. Alternatively, adjacent paper layers within the tube can be retained with an adhesive that provides the tube with sealing properties.

Suitable materials for forming tubes are well known in the art and include cellulose acetate, hard paper (ie, paper having a basis weight of at least 90 grams/square meter), polymeric films such as cellulosic films, and cardboard. Including but not limited to.

In some embodiments, the ratio of the weight of the hollow tubular segment to the volume of the internal depression defined by the hollow tubular segment is preferably less than 1 milligram/millimeter. More preferably, the ratio of the weight of the hollow tubular segment to the volume of the internal depression defined by the hollow tubular segment is less than 0.5 milligram/cubic millimeter.

In a particularly preferred embodiment, the ratio of the weight of the hollow tubular segment to the volume of the internal recess defined by the hollow tubular segment is less than 0.25 milligrams/millimeter. More preferably, the ratio of the weight of the hollow tubular segment to the volume of the internal depression defined by the hollow tubular segment is less than 0.2 milligrams/cubic millimeter. Even more preferably, the ratio of the weight of the hollow tubular segment to the volume of the internal depression defined by the hollow tubular segment is less than 0.1 milligram/cubic millimeter.

In a hollow tubular segment having a ratio of the weight of the hollow tubular segment to the volume of the internal cavity defined by the hollow tubular segment within the above range, the volume of the cavity is advantageously maximized while The tubular segment contributes to the overall structural strength of the aerosol-generating article and ensures that the rod of the aerosol-generating substrate remains effectively spaced from the mouthpiece.

In an exemplary embodiment, the hollow tubular segment has an equivalent diameter of 7 millimeters and is formed from a wrapper having a basis weight of 110 gsm and weighs 2.5 milligrams/millimeter. For one such hollow tubular segment, the ratio of the weight of the hollow tubular segment to the volume of the internal depression defined by the hollow tubular segment is about 0.065 milligrams/cubic millimeter.

In another exemplary embodiment, a hollow tubular segment having an equivalent inner diameter of 5.3 millimeters can be provided as a cellulose acetate tube having a weight of 9.5 milligrams/millimeter. For one such hollow tubular segment, the ratio of the weight of the hollow tubular segment to the volume of the internal recess defined by the hollow tubular segment is about 0.43 milligrams/cubic millimeter.

In an aerosol-generating article according to the present invention, the hollow tubular segment is substantially empty and therefore contributes only a substantially slight overall RTD, so that the overall RTD of the article is essentially a rod. RTD and the RTD of the mouthpiece. In practice, the hollow tubular segment may be adapted to generate an RTD in the range of approximately 0 millimeter H ₂ O (about 00 Pa) to approximately 20 m millimeter H ₂ O (about 200 Pa). The hollow tubular segment is preferably adapted to generate an RTD of about 0 millimeter H ₂ O (about 00 Pa) to about 10 millimeter H ₂ O (about 100 Pa).

The aerosol-generating article preferably has an overall RTD of less than about 90 millimeters H ₂ O (about 900 Pa). More preferably, the aerosol-generating article has an overall RTD of less than about 80 millimeters H ₂ O (about 800 Pa). Even more preferably, the aerosol-generating article has an overall RTD of less than about 70 millimeters H ₂ O (about 700 Pa).

Additionally or alternatively, the aerosol-generating article preferably has an overall RTD of at least about 30 millimeters H ₂ O (about 300 Pa). More preferably, the aerosol-generating article has an overall RTD of at least about 40 millimeters H ₂ O (about 400 Pa). Even more preferably, the aerosol-generating article has an overall RTD of at least about 50 millimeters H ₂ O (about 500 Pa).

The RTD of an aerosol-generating article is evaluated as the negative pressure that needs to be applied to the downstream end of the mouthpiece under test conditions defined in ISO 3402 in order to maintain a stable air flow rate of 17.5 ml/s through the mouthpiece. Can be done. The RTD values above are intended to be measured on the aerosol-generating article itself (ie, prior to inserting the article into the aerosol-generating device) without blocking perforation of the ventilation zone. ..

If desired or necessary, for example, the length and density (denier per filament) of the filtration material of the mouthpiece can be adjusted to achieve a sufficiently high RTD of the aerosol-generating article. Additionally or alternatively, additional filter sections may be included in the aerosol generating article. By way of example, such an additional filter section may be included between the rod of the aerosol-generating substrate and the hollow tubular segment. Such additional filter section preferably comprises a filter material such as, for example, cellulose acetate. The length of the additional filter section is preferably about 4 millimeters to about 8 millimeters, preferably about 5 millimeters to about 7 millimeters.

In some embodiments, the aerosol-generating article according to the present invention comprises an additional support element disposed between the rod of the aerosol-generating substrate and the hollow tubular segment in longitudinal alignment therewith. sell. More particularly, the support element is preferably provided immediately downstream of the rod and immediately upstream of the hollow tubular element.

The support element is provided as a tubular element. The support element may be formed of any suitable material or combination of materials. For example, the support element is selected from the group consisting of cellulose acetate, cardboard, crimped paper (such as crimped heat resistant paper or crimped sulfuric acid paper), and polymeric materials such as low density polyethylene (LDPE). It may be formed of one or more materials. In a preferred embodiment, the support element is provided as a hollow cellulose acetate tube.

The support element preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article. The support element may have an outer diameter of about 5 millimeters to about 12 millimeters, for example about 5 millimeters to about 10 millimeters, or about 6 millimeters to about 8 millimeters. In the preferred embodiment, the support element has an outer diameter of about 7.2 millimeters.

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

The support element can have a length of about 5 millimeters to about 15 millimeters. In one preferred embodiment, the support element has a length of about 8 millimeters.

During insertion of the heating element of the aerosol-generating device into the aerosol-forming substrate of the aerosol-generating article, the user has to overcome the resistance of the aerosol-forming substrate of the aerosol-generating article to the insertion of the heating element of the aerosol-generating device. It may be necessary to apply some force. This can damage one or both of the aerosol-generating article and the heating element of the aerosol-generating device. In addition, the application of force during insertion of the heating element of the aerosol-generating device into the aerosol-forming substrate of the aerosol-generating article may displace the aerosol-forming substrate in the aerosol-generating article. This can result in aerosol generator heating elements that are not fully inserted into the aerosol-forming substrate, which results in uneven and inefficient heating of the aerosol-forming substrate of the aerosol-generating article. Can cause. Advantageously, the support element is configured to resist downstream movement of the aerosol-forming substrate during insertion of the heating element of the aerosol-generating device into the aerosol-forming substrate of the aerosol-generating article.

The distance between the ventilation zone and the upstream end of the aerosol-generating article is preferably less than about 50 millimeters. More preferably, the distance between the ventilation zone and the upstream end of the aerosol-generating article is less than about 45 millimeters. Even more preferably, the distance between the ventilation zone and the upstream end of the aerosol-generating article is less than about 40 millimeters.

Additionally or alternatively, the distance between the ventilation zone and the upstream end of the aerosol-generating article is preferably at least about 12 millimeters. More preferably, the distance between the ventilation zone and the upstream end of the aerosol-generating article is preferably at least about 15 millimeters. Even more preferably, the distance between the ventilation zone and the upstream end of the aerosol-generating article is preferably at least about 20 millimeters. In a particularly preferred embodiment, the distance between the ventilation zone and the upstream end of the aerosol-generating article is preferably at least about 25 millimeters.

The distance between the ventilation zone and the downstream end of the rod of the aerosol-generating substrate is preferably at least about 2 millimeters. More preferably, the distance between the ventilation zone and the downstream end of the rod of the aerosol-generating substrate is at least about 5 millimeters. Even more preferably, the distance between the ventilation zone and the downstream end of the rod of the aerosol-generating substrate is at least about 10 millimeters. In some particularly preferred embodiments, the distance between the ventilation zone and the downstream end of the rod of the aerosol-generating substrate can be at least about 15 millimeters.

Additionally or alternatively, the distance between the ventilation zone and the downstream end of the rod of the aerosol-generating substrate is preferably less than about 35 millimeters. More preferably, the distance between the ventilation zone and the downstream end of the rod of the aerosol-generating substrate is less than about 30 millimeters. Even more preferably, the distance between the ventilation zone and the downstream end of the rod of the aerosol-generating substrate is less than about 25 millimeters.

In practice, the ventilation zone comprises a recess internally defined by the hollow tubular segment, an upstream sub-recess extending longitudinally from the upstream end of the hollow tubular segment to the location of the ventilation zone, and a location of the ventilation zone. The hollow tubular segment is divided into a downstream sub-recess extending longitudinally to the downstream end. While not wishing to be bound by theory, in the upstream sub-dip the volatilized species of aerosol flow traveling along the hollow tubular segment slowly imparts some of its heat to the peripheral wall of the hollow tubular segment. It is understood that when it cools down, the aerosol particles begin to nucleate. On the other hand, in the downstream sub-dip, the aerosol stream and the circulating air are rapidly mixed, which rapidly cools the volatilized species of the aerosol stream, and nucleates new and existing aerosol particles as they progress toward the mouthpiece. Favors the growth of aerosol particles.

The ratio of the length of the upstream depression to the length of the downstream depression is preferably less than 1.5. More preferably, the ratio of the length of the upstream depression to the length of the downstream depression is less than 1. Even more preferably, the ratio of the length of the upstream depression to the length of the downstream depression is less than 0.67.

Additionally or alternatively, it is preferred that the ratio between the length of the upstream depression and the length of the downstream depression is at least about 0.15. More preferably, the ratio of the length of the upstream depression to the length of the downstream depression is preferably at least about 0.2. Even more preferably, the ratio of the length of the upstream depression to the length of the downstream depression is preferably at least about 0.35.

Similarly, the ventilation zone divides the aerosol-generating article into two sections, respectively upstream and downstream of the location of the ventilation zone.

The ratio of the length of the upstream section of the aerosol-generating article to the length of the downstream section of the aerosol-generating article is preferably less than 2.5. More preferably, the ratio of the length of the upstream section of the aerosol-generating article to the length of the downstream section of the aerosol-generating article is less than 2. Even more preferably, the ratio of the length of the upstream section of the aerosol-generating article to the length of the downstream section of the aerosol-generating article is less than 1.5. In a particularly preferred embodiment, the ratio of the length of the upstream section of the aerosol-generating article to the length of the downstream section of the aerosol-generating article is less than 1.

Additionally or alternatively, the ratio of the length of the upstream section of the aerosol-generating article to the length of the downstream section of the aerosol-generating article is preferably at least about 0.25. More preferably, the ratio of the length of the upstream section of the aerosol-generating article to the length of the downstream section of the aerosol-generating article is at least about 0.33. Even more preferably, the ratio of the length of the upstream section of the aerosol-generating article to the length of the downstream section of the aerosol-generating article is at least about 0.5.

The aerosol-generating article according to the present invention advantageously facilitates adjustment and control of the overall RTD of the article. This is because the overall RTD of the article depends on a finite, small number of component RTDs, and the provision of ventilation zones contributes to the reduction of the overall RTD of the article. Thus, advantageously, RTD variation between aerosol-generating articles can be reduced.

Accordingly, the present invention may also provide a pack comprising 10 or more aerosol generating articles as described above, wherein the RTD of the aerosol generating article having the highest RTD of at least 10 aerosol generating articles and at least 10 The difference from the RTD of the aerosol-generating article having the lowest RTD of the individual aerosol-generating articles is less than 10 mm H ₂ O (about 100 Pascals). In such a pack, between the RTD of the aerosol-generating article having the highest RTD of at least 10 aerosol-generating articles and the RTD of the aerosol-generating article having the lowest RTD of at least 10 aerosol-generating articles. The difference is preferably less than 9 mmH ₂ O (about 90 Pascals), more preferably less than 8 mmH ₂ O (about 80 Pascals), and even more preferably less than 7 mmH ₂ O (about 70 Pascals). ..
Hereinafter, the present invention will be further described with reference to the accompanying drawings.

FIG. 1 shows a schematic side sectional view of an aerosol-generating article according to the present invention. FIG. 2 shows a schematic side sectional view of another embodiment of an aerosol-generating article according to the present invention. FIG. 3 shows a schematic side sectional view of a further embodiment of an aerosol-generating article according to the invention.

The aerosol-generating article 10 shown in FIG. 1 comprises a rod of an aerosol-generating substrate 12, a hollow cellulose acetate tube 14, a hollow tubular segment 16 and a mouthpiece segment 18. These four elements are longitudinally arranged end-to-end and surrounded by an outer wrapper 20 to form an aerosol-generating article 10. The aerosol-generating article 10 has a mouth end 22 and a distal end 24 located at the end of the article opposite the mouth end 22. The aerosol-generating article 10 shown in FIG. 1 is particularly suitable for use with an electrically actuated aerosol-generating device that includes a heater for heating the rod of the aerosol-forming substrate.

The rod of aerosol-generating substrate 12 has a length of about 12 millimeters and a diameter of about 7 millimeters. The rod 12 is cylindrical in shape and has a substantially circular cross section. The rod 12 comprises a collection of sheets of homogenized tobacco material. The sheet of homogenized tobacco material comprises 10 weight percent glycerin on a dry basis. The hollow cellulose acetate tube 14 has a length of about 8 millimeters and a thickness of 1 millimeter.

Mouthpiece segment 18 comprises a plug of cellulose acetate tow that is 8 denier per filament and has a length of about 7 millimeters.

The hollow tubular segment 16 is provided as a cylindrical tube having a length of about 18 millimeters, with a tube wall thickness of about 100 micrometers.

More specifically, the hollow tubular segment 16 may be formed from paper having a basis weight of, for example, 110 gsm and has a weight of 45 milligrams (ie, 2.5 milligrams/millimeter of length). The equivalent inner diameter of the hollow tubular segment 16 is about 7 millimeters. Therefore, the volume of the depression internally defined by the hollow tubular segment 16 is about 693 cubic millimeters. Therefore, the ratio of the weight of the hollow tubular segment to the volume of the internal recess defined by the hollow tubular segment 16 is about 0.065. The aerosol-generating article 10 comprises a ventilation zone 26 provided approximately 5 millimeters from the upstream end of the mouthpiece segment 18. Accordingly, the ventilation zone 26 is about 12 millimeters from the downstream end of the aerosol-generating article and about 13 millimeters from the upstream end of the hollow tubular segment.

Therefore, the ventilation zone 26 is approximately 21 millimeters from the downstream end of the rod 12. FIG. 2 illustrates another embodiment of an aerosol generating article according to the present invention. The aerosol-generating article 30 of FIG. 2 has the same structure as the aerosol-generating article 10 of FIG. 1, and is substantially different from the aerosol-generating article 10 only in the lengths of specific constituent elements. Will be described below to the extent that they are different. Wherever possible, the same reference numbers are used for corresponding components having the same structure or functional function.

In the aerosol-generating article 30 of FIG. 2, the rod 12 and the hollow cellulose acetate tube 14 have the same length as the aerosol-generating article 10 of FIG. However, the mouthpiece segment is 11 denier per filament and includes a plug of cellulose acetate tow having a length of about 12 millimeters, and the hollow tubular segment 14 has a length of about 13 millimeters. Vent zone 26 is provided approximately 6 millimeters from the upstream end of mouthpiece segment 18 and approximately 7 millimeters from the upstream end of the hollow tubular segment. Therefore, the ventilation zone 26 is approximately 15 millimeters from the downstream end of the rod 12.

In the embodiment of FIG. 2, the hollow tubular segment 16 may be provided as a cylindrical tube of cellulose acetate having, for example, a length of about 18 millimeters and a peripheral wall thickness of about 1 millimeter, and weighs 171. Milligrams (ie, 9.5 milligrams/millimeter of length).

The equivalent inner diameter of the hollow tubular segment 16 may be about 5.3 millimeters. Therefore, the volume of the depression internally defined by the hollow tubular segment 16 is about 397 cubic millimeters. Therefore, the ratio of the weight of the hollow tubular segment to the volume of the internal recess defined by the hollow tubular segment 16 is about 0.43. FIG. 3 illustrates yet another embodiment of an aerosol generating article according to the present invention. The aerosol-generating article 40 of FIG. 3 differs structurally from the aerosol-generating article 10 of FIG. 1 and the aerosol-generating article 30 of FIG. 2 in that it does not include a hollow cellulose acetate tube as a support element. Therefore, the lengths of the three main components are also different. Wherever possible, the same reference numbers are used for corresponding components having the same structure or functional function.

In the aerosol-generating article 40 of FIG. 3, rod 12 has a length of about 12 millimeters, hollow tubular segment 14 has a length of about 26 millimeters, mouthpiece segment 18 has a length of about 12 millimeters, And a plug of cellulose acetate tow having 11 denier per filament. Vent zone 26 is provided approximately 5 millimeters from the upstream end of mouthpiece segment 18 and approximately 21 millimeters from the upstream end of the hollow tubular segment, which in this embodiment coincides with the downstream end of rod 12.

Claims (15)

An aerosol-generating article for producing an inhalable aerosol when heated, wherein the aerosol-generating article comprises:
An aerosol generating substrate rod,
A mouthpiece segment including a plug of filtration material, the mouthpiece segment located downstream of the rod and longitudinally aligned with the rod,
A hollow tubular segment located between the rod and the mouthpiece segment, the hollow tubular segment being longitudinally aligned with the rod and the mouthpiece segment, the hollow tubular segment being an upstream end of the mouthpiece segment. A hollow tubular segment defining an indentation extending entirely up to,
A ventilation zone located along the hollow tubular segment,
The hollow tubular segment at the location of the ventilation zone has an equivalent inner diameter of at least about 5 millimeters,
An aerosol generating article, wherein the rod of the aerosol generating substrate comprises at least an aerosol forming body and has an aerosol forming body content of at least about 10 percent by dry weight. The aerosol-generating article of claim 1, wherein the hollow tubular segment comprises a wrapper, the wrapper surrounding the rod and the mouthpiece segment. The hollow tubular segment comprises a tube formed of a polymeric or cellulosic material, and the heated aerosol generating article further comprises a wrapper surrounding the rod, the tube, and the mouthpiece segment. An aerosol-generating article as described. 4. The aerosol-generating article according to any one of claims 1 to 3, wherein the equivalent inner diameter of the hollow tubular segment is substantially constant along the length of the hollow tubular segment. 5. The aerosol-generating article according to any one of claims 1 to 4, wherein the ventilation zone is located along the hollow tubular segment at least 4 millimeters from the downstream end of the mouthpiece segment. The aerosol-generating article of claim 4, wherein the ventilation zone is located along the hollow tubular segment less than 25 millimeters from the downstream end of the mouthpiece segment. 7. The aerosol-generating article of any one of claims 1-6, wherein the ventilation zone is located along the hollow tubular segment less than about 18 millimeters from the upstream end of the hollow tubular segment. 8. The aerosol-generating article of any one of claims 1-7, wherein the aerosol-generating article has a ventilation level of at least about 10 percent. 9. The aerosol-generating article of any one of claims 1-8, wherein the aerosol-generating article has a ventilation level of less than about 60 percent. 10. The aerosol-generating article of any one of claims 1-9, wherein the rod has a length of less than about 15 millimeters. 11. The aerosol-generating article of any one of claims 1-10, wherein the hollow tubular segment has a length of about 10 millimeters to about 30 millimeters. 12. The aerosol-generating article of any one of claims 1-11, wherein the aerosol-generating article has an overall length of about 40 millimeters to about 70 millimeters. 13. The aerosol-generating article of any one of claims 1-12, wherein the thickness of the peripheral wall of the hollow tubular segment at the location of the ventilation zone is less than about 1.5 millimeters. 14. The aerosol-generating article of any one of claims 1-13, wherein the thickness of the hollow tubular segment is at least about 100 micrometers. The aerosol RTD of generating article is about 30 mm H ₂ O ~ about 90 mm H ₂ O, aerosol generation article according to any one of claims 1 to 14.