Aerosol-generating article with a wrapper having an overlap region

Abstract

The aerosol-generating article (10) comprises an aerosol-forming substrate (11) and a wrapper (30) surrounding the aerosol-forming substrate. The wrapper defines an overlap region (41) where the wrapper overlaps itself, the overlap region including a first section (42) and a second section (43) disposed externally on the first section. The second section includes a crease (44) at one end of the wrapper that defines a folded section (45), the folded section being sandwiched between the first and second sections. An exterior adhesive is disposed between the folded section and the second section.

Description

[Technical field]

[0001] The present invention relates to an aerosol-generating article comprising an aerosol-forming substrate, the aerosol-generating article being usable to generate an inhalable aerosol upon heating. [Background technology]

[0002] Aerosol-generating articles in which an aerosol-forming substrate, such as a tobacco-containing substrate, is heated rather than combusted are known in the art. The purpose of such heatable aerosol-generating articles is to reduce the potentially harmful by-products produced by the combustion and thermal decomposition of tobacco in conventional cigarettes.

[0003] In a heatable aerosol-generating article, an inhalable aerosol is typically generated by heat transfer from a heater to an aerosol-forming substrate. During heating, volatile compounds are released from the aerosol-forming substrate and entrained in the air. For example, the volatile compounds may be entrained in air that passes through, passes around, or is otherwise drawn into the vicinity of the aerosol-generating article. As the released volatile compounds cool, they condense to form an aerosol. The aerosol can be inhaled by a user. The aerosol can contain aromas, flavors, nicotine, and other desirable elements.

[0004] The heating element may be included in an aerosol generating device. The combination of the aerosol generating article and the aerosol generating device may form an aerosol generating system.

[0005] The heatable aerosol-generating article may comprise one or more wrappers surrounding at least a portion of the aerosol-generating article. Advantageously, the one or more wrappers prevent the user from touching the aerosol-forming substrate, which may help to maintain a high level of hygiene. The provision of the one or more wrappers may also contribute to securing components of the aerosol-generating article together. Summary of the Invention [Problem to be solved by the invention]

[0006] However, when a wrapper surrounds at least a portion of the aerosol-generating article, the wrapper may include at least one free edge that is disposed on a section of the wrapper where the free edges overlap. This arrangement may be detrimental to the mechanical stability of the aerosol-generating article and may interfere with the manufacture and handling of the aerosol-generating article.

[0007] It is therefore desirable to provide an aerosol-generating article having one or more wrappers and which has improved mechanical stability. [Means for solving the problem]

[0008] An aerosol-generating article may be provided. The aerosol-generating article may comprise a wrapper surrounding an aerosol-forming substrate. The wrapper may define an overlap region where the wrapper overlaps itself, the overlap region including a first section and a second section disposed externally on the first section. The second section may include a crease or score defining a folded section at one end of the wrapper. The folded section may be sandwiched between the first section and the second section.

[0009] An aerosol-generating article may be provided, the aerosol-generating article comprising: an aerosol-forming substrate; a wrapper surrounding the aerosol-forming substrate; the wrapper defines an overlap region where the wrapper overlaps itself, the overlap region including a first section and a second section disposed externally over the first section; the second section includes a crease or score defining a folded section at one end of the wrapper; The folded section is sandwiched between the first section and the second section.

[0010] The term "aerosol-generating article" is used herein to mean an article in which an aerosol-forming substrate is heated to generate an inhalable aerosol for delivery to a consumer. As used herein, the term "aerosol-forming substrate" relates to a substrate capable of releasing volatile compounds capable of forming an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. The aerosol-forming substrate is typically part of the aerosol-generating article.

[0011] The aerosol-forming substrate may comprise nicotine. The nicotine-containing aerosol-forming substrate may be a nicotine salt matrix.

[0012] The aerosol-forming substrate may comprise a liquid. The aerosol-forming substrate may comprise a solid component and a liquid component. Preferably, the aerosol-forming substrate may comprise a solid.

[0013] The aerosol-forming substrate may comprise a plant-derived material. The aerosol-forming substrate may comprise tobacco. The aerosol-forming substrate may comprise a tobacco-containing material comprising volatile tobacco flavour compounds which are released from the aerosol-forming substrate upon heating. The aerosol-forming substrate may comprise a non-tobacco material. The aerosol-forming substrate may comprise a homogenised plant-derived material.

[0014] As used herein, the term "aerosol-generating device" refers to a device that typically includes a heater that interacts with an aerosol-forming substrate of an aerosol-generating article to generate an aerosol.

[0015] As used herein in connection with the present invention, the term "rod" is used to denote a generally cylindrical element of substantially circular, oval or elliptical cross section.

[0016] The term "longitudinal" as used herein refers to a direction corresponding to a major longitudinal axis of the aerosol-generating article extending between the upstream and downstream ends of the aerosol-generating article. The terms "upstream" and "downstream" as used herein describe the relative positions of an element (or portion of an element) of the aerosol-generating article with respect to the direction in which aerosol is transported through the aerosol-generating article during use.

[0017] In use, air is drawn longitudinally through the aerosol-generating article. The term "transverse" refers to a direction perpendicular to the longitudinal axis. Any reference to a "cross section" of an aerosol-generating article or a component of an aerosol-generating article refers to a transverse cross section, unless otherwise specified.

[0018] The term "length" refers to the dimension of a component of an aerosol-generating article along its longitudinal axis.

[0019] By providing one end of the wrapper with a folded section sandwiched between the first and second sections of the wrapper, that end of the wrapper is not a free end of the second section that is disposed overlapping the first section of the wrapper, and thus the folded section may improve the mechanical stability of an aerosol-generating article comprising the wrapper.

[0020] Because the folded section is sandwiched between the first and second sections, the folded section does not introduce significant irregularities into the outer surface of the wrapper, which can be beneficial for ease of handling of the aerosol-generating article during manufacture and transportation.

[0021] A configuration in which the folded section is defined by creases or scores contained in the second section of the wrapper may be desirable compared to other wrapper configurations that include folded sections in that it avoids the formation of or minimizes the size of irregular depressions in the interior space defined by the wrapper. Because the interior space defined by the wrapper may be intended to contain the aerosol-forming substrate, this arrangement may make it possible to reduce the amount of aerosol-forming substrate that needs to be used to manufacture the aerosol-generating article. It may also improve the manufacturing process, because irregular depressions may make the insertion of the aerosol-forming substrate more difficult and time-consuming.

[0022] The inner adhesive may be disposed between the folded section and the first section. The outer adhesive may be disposed between the folded section and the second section. The provision of an inner adhesive or an outer adhesive may contribute to improving the mechanical stability of the aerosol-generating article. When an inner adhesive and an outer adhesive are provided, a greater improvement in mechanical stability may be achieved.

[0023] The inner adhesive and the outer adhesive may be the same adhesive.

[0024] The folded section may extend over at least about 0.75 millimetres of the periphery of the aerosol-forming substrate, or over at least about 1 millimetre of the periphery of the aerosol-forming substrate.

[0025] The folded section may extend over a maximum of about 2.5 millimetres of the periphery of the aerosol-forming substrate, or a maximum of about 2 millimetres of the periphery of the aerosol-forming substrate.

[0026] Preferably, the folded section extends over about 0.75 mm to about 2.5 mm of the periphery of the aerosol-forming substrate, or about 0.75 mm to about 2 mm of the periphery of the aerosol-forming substrate, or about 1 mm to 2.5 mm of the periphery of the aerosol-forming substrate. More preferably, the folded section extends over about 1 mm to about 2 mm of the periphery of the aerosol-forming substrate.

[0027] The folded section may extend over at least about 3 percent of the periphery of the aerosol-forming substrate, or at least about 4 percent of the periphery of the aerosol-forming substrate.

[0028] The folded section may extend over up to about 12 percent of the periphery of the aerosol-forming substrate, or up to about 10 percent of the periphery of the aerosol-forming substrate.

[0029] Preferably, the folded section extends over about 3 percent to about 12 percent of the periphery of the aerosol-forming substrate, or about 3 percent to about 10 percent of the periphery of the aerosol-forming substrate, or about 4 percent to about 12 percent of the periphery of the aerosol-forming substrate, more preferably about 4 percent to about 10 percent of the periphery of the aerosol-forming substrate.

[0030] The second section may extend across at least about 0.75 millimetres of the periphery of the aerosol-forming substrate, or across at least about 1 millimetre of the periphery of the aerosol-forming substrate.

[0031] The second section may extend over a maximum of about 2.5 millimetres of the periphery of the aerosol-forming substrate, or a maximum of about 2 millimetres of the periphery of the aerosol-forming substrate.

[0032] Preferably, the second section extends over about 0.75 mm to about 2.5 mm of the periphery of the aerosol-forming substrate, or about 0.75 mm to about 2 mm of the periphery of the aerosol-forming substrate, or about 1 mm to about 2.5 mm of the periphery of the aerosol-forming substrate. More preferably, the second section extends over about 1 mm to about 2 mm of the periphery of the aerosol-forming substrate.

[0033] The second section may extend over at least about 3 percent of the periphery of the aerosol-forming substrate, or over at least about 4 percent of the periphery of the aerosol-forming substrate.

[0034] The second section may extend over up to about 12 percent of the periphery of the aerosol-forming substrate, or up to about 10 percent of the periphery of the aerosol-forming substrate.

[0035] Preferably, the second section extends over about 3 percent to about 12 percent of the periphery of the aerosol-forming substrate, or about 3 percent to about 10 percent of the periphery of the aerosol-forming substrate, or about 4 percent to about 12 percent of the periphery of the aerosol-forming substrate. More preferably, the second section extends over about 4 percent to about 10 percent of the periphery of the aerosol-forming substrate.

[0036] The periphery of the aerosol-forming substrate may also be referred to as the periphery of the aerosol-forming substrate.

[0037] The wrapper may have a basis weight of about 10 grams per square meter to about 28 grams per square meter. Preferably, the wrapper may have a basis weight of about 10 grams per square meter to about 16 grams per square meter.

[0038] Basis weights in these ranges can be beneficial to allow for the formation of folded sections within the wrapper.

[0039] The wrapper may have a porosity of about 30 to about 80 Coresta units. Preferably, the wrapper may have a porosity of about 30 to about 50 Coresta units. Most preferably, the wrapper may have a porosity of 30 to 40 Coresta units.

[0040] The wrapper may have a roughness of about 50 Bekk seconds to about 1000 Bekk seconds. More preferably, the wrapper may have a roughness of about 100 Bekk seconds to about 200 Bekk seconds.

[0041] Roughness, expressed in Beck seconds, is measured by a standard test using a BEKK Smoothness Tester, which generates a vacuum and measures the time it takes for the vacuum to drop from 50.66 kPa to 48.00 kPa. This test is recognized by the international standard ISO 5627.

[0042] The inner adhesive may include one or more of gum arabic, natural or synthetic resins, starch and varnish. The outer adhesive may include one or more of gum arabic, natural or synthetic resins, starch and varnish. Such adhesives may be useful in providing a robust attachment to the overlap area of ​​the wrappers.

[0043] The heating element may be embedded within the aerosol-forming substrate. An embedded heating element is an internal heating element. As used herein, the term "internal heating element" refers to a heating element that is configured to be inserted or placed within the aerosol-forming substrate or flavor substrate.

[0044] Aerosol-generating articles comprising a heating element embedded within the aerosol-forming substrate may be advantageous in that enhanced heat distribution from the heating element to the aerosol-forming substrate may be achieved when the aerosol-generating article is in use.

[0045] The heating element may be a susceptor.

[0046] As used herein, the term "susceptor" refers to an element that includes a material capable of converting magnetic energy into heat. When the susceptor is placed in a changing magnetic field, such as a changing magnetic field generated by an inductor coil, the susceptor heats up.

[0047] Heating of the susceptor can be the result of hysteresis losses and / or eddy currents induced in the susceptor, depending on the electrical and magnetic properties of the susceptor material. Hysteresis losses occur in ferromagnetic or ferrimagnetic susceptor materials due to magnetic domains in the material being switched under the influence of a fluctuating electromagnetic field. Eddy currents can be induced if the susceptor material is conductive. In the case of a conductive ferromagnetic or ferrimagnetic susceptor material, heat can be generated by both eddy currents and hysteresis losses. Thus, the susceptor can be heatable by at least one of hysteresis losses or eddy currents, depending on the electrical and magnetic properties of the susceptor material.

[0048] The heating element may be completely surrounded by the aerosol-forming substrate and extend along the entire length of the aerosol-forming substrate, which may provide an optimized heat distribution within the aerosol-forming substrate when the heating element is heated.

[0049] The susceptor may have a thickness of about 35 micrometers to about 85 micrometers.The susceptor may have a thickness of about 45 micrometers to about 75 micrometers.The susceptor may have a thickness of about 55 micrometers to about 65 micrometers.

[0050] It has been found that in aerosol-generating articles provided with susceptors having the above-mentioned thicknesses, heat generation and heat distribution throughout the aerosol-forming substrate can be achieved particularly effectively and efficiently. Without wishing to be bound by theory, it is believed that this is because such susceptors are adapted to provide optimal heat generation and heat transfer due to the surface area and inductive force of the susceptor. In contrast, thinner susceptors may be too easily deformed to maintain the desired shape and orientation within the aerosol-forming substrate during the manufacture of the aerosol-generating article, resulting in a less uniform and less finely tuned heat distribution during use. At the same time, thicker susceptors may be more difficult to cut to precise and consistent lengths, which may also affect how the susceptor is provided accurately in longitudinal alignment within the aerosol-forming substrate, and thus the uniformity of the heat distribution within the aerosol-forming substrate. These beneficial effects are particularly felt when the susceptor extends all the way to the downstream end of the aerosol-forming substrate. This is believed to be because there is no aerosol-forming substrate within the aerosol-forming substrate located downstream of the susceptor that could contribute to resistance to withdrawal (RTD) and therefore the RTD downstream of the susceptor can essentially be minimized.

[0051] The susceptor may be an elongated susceptor disposed substantially longitudinally within the aerosol-forming substrate.

[0052] The term "elongated" when used to describe a susceptor means that the susceptor has a length dimension that is greater than its width or its thickness dimension, for example, greater than twice its width or its thickness dimension.

[0053] The susceptor may be disposed substantially longitudinally within the aerosol-forming substrate, meaning that the length dimension of the elongated susceptor is disposed approximately parallel to the longitudinal direction of the aerosol-forming substrate, for example within ±10 degrees of parallel to the longitudinal direction of the aerosol-forming substrate. The elongated susceptor may be positioned at a radially central position within the aerosol-forming substrate and extend along the longitudinal axis of the aerosol-forming substrate.

[0054] The susceptor may have substantially the same length as the aerosol-forming substrate.

[0055] The susceptor may be in the form of a pin, rod, strip, or blade.

[0056] The susceptor may have a length of about 5 millimeters to about 15 millimeters, for example, about 6 millimeters to about 12 millimeters, and more preferably about 8 millimeters to about 10 millimeters.

[0057] The susceptor may have a width of at least about 1 millimeter, more preferably at least about 2 millimeters. Typically, the susceptor may have a width of up to 8 millimeters, preferably no more than about 6 millimeters.

[0058] If the susceptor has a uniform cross-section, such as a circular cross-section, it may have a width or diameter of about 1 millimeter to about 5 millimeters.

[0059] When the susceptor has the form of a strip or blade, the strip or blade may have a rectangular cross section, preferably having a width of about 2 millimeters to about 8 millimeters, more preferably about 3 millimeters to about 6 millimeters. A susceptor in the form of a strip of blade may have a width of about 4 millimeters.

[0060] The elongated susceptor may have a thickness of about 57 micrometers to about 63 micrometers. Even more preferably, the elongated susceptor may have a thickness of about 58 micrometers to about 62 micrometers. Most preferably, the elongated susceptor has a thickness of about 60 micrometers.

[0061] The aerosol-generating article may have a diameter of from about 3 mm to about 8 mm.

[0062] The wrapper may have a thickness of about 60 micrometers to about 200 micrometers, preferably about 78 micrometers to about 160 micrometers, more preferably 78 micrometers to about 140 micrometers, more preferably about 100 micrometers to about 140 micrometers, and most preferably about 125 micrometers to about 140 micrometers.

[0063] A wrapper thickness within such a range may result in a suitable balance between the overall thickness of the overlap region and the thickness of the remainder of the wrapper.

[0064] The aerosol-forming substrate may include one or more of tobacco, nicotine, a gel composition, and a flavoring agent.

[0065] Advantageously, the gel composition may be solid at room temperature. "Solid" in this context means that the gel has a stable size and shape and does not flow. Room temperature in this context means 25 degrees Celsius. Gels may be defined as substantially diluted crosslinked systems that do not exhibit flowability at steady state. On a weight basis, gels may be almost liquid, yet they behave like solids due to a three-dimensional crosslinked network within the liquid. Crosslinks within the fluid give the gel its structure (hardness). In this way, gels may be a dispersion of liquid molecules within a solid, with liquid particles dispersed in a solid medium.

[0066] The aerosol generation may comprise a filter positioned longitudinally downstream of the aerosol-forming substrate.

[0067] The term "filter" is used to denote a section of an aerosol-generating article that is configured to at least partially remove gas phase or particulate phase components, or both gas phase and particulate phase components, from the mainstream aerosol drawn through the filter.

[0068] The aerosol-generating article may have a length of from about 30 mm to about 100 mm.

[0069] The aerosol-generating article may comprise a support element positioned downstream of the aerosol-forming substrate.

[0070] The support element is often provided in the form of an annular tube of filtration material, often referred to as a hollow acetate tube. Such hollow tubular support elements are configured to resist downstream movement of the aerosol-forming substrate during handling of the aerosol-generating article, for example during insertion of a heating element into the aerosol-forming substrate. Open spaces within the hollow tubular support element may provide openings for aerosol to flow from the aerosol-forming substrate towards the mouth end of the aerosol-generating article.

[0071] The support element may be positioned immediately downstream of the aerosol-forming substrate.

[0072] Where the aerosol-generating article comprises a filter and a support element, the filter may be positioned longitudinally downstream of the support element.

[0073] The filter may be positioned longitudinally immediately downstream of the support element.

[0074] Because the support element may be useful and sufficient to provide customization of the aerosol formed according to user preferences, the filter may be located immediately downstream of the support element, i.e., without intermediate components such as an aerosol cooling element, etc. Thus, the aerosol-generating article may achieve reduced gas and particulate phase components while requiring fewer production steps and enabling a more consistent experience.

[0075] However, the aerosol-generating article may comprise an aerosol cooling element downstream of the support element. Preferably, the aerosol cooling element may be located between the support element and the filter.

[0076] As used herein, "aerosol cooling element" refers to a component of an aerosol-generating article located downstream of an aerosol-forming substrate such that the aerosol formed by volatile compounds released from the aerosol-forming substrate during use passes through and is cooled by the aerosol cooling element before being inhaled by the consumer. The aerosol cooling element is preferably located between the aerosol-forming substrate and the mouthpiece. The aerosol cooling element has a large surface area but produces a low pressure drop. Filters and other mouthpieces that produce a high pressure drop (e.g., filters formed of fiber bundles) are not considered to be aerosol cooling elements. Chambers and cavities within the aerosol-generating article are not considered to be aerosol cooling elements.

[0077] The support element may comprise a first hollow tubular segment.The aerosol cooling element may comprise a second hollow tubular segment.

[0078] The aerosol-generating article may comprise a mouthpiece located at the downstream end of the aerosol-generating article. Providing a mouthpiece may be desirable to facilitate inhalation of the aerosol by a user.

[0079] The aerosol-generating article may comprise an upstream element located at the upstream end of the aerosol-generating article, which may ensure that, if the aerosol-generating article comprises a susceptor, a consumer cannot accidentally come into contact with the heated susceptor after use, and, if the aerosol-generating article comprises a susceptor, the provision of the upstream element may advantageously prevent the susceptor from becoming dislodged.

[0080] The aerosol-forming substrate may have any suitable cross-sectional shape. For example, the substrate may have a circular, elliptical, stadium-shaped, rectangular or triangular cross-sectional shape. Preferably, the substrate has a circular cross-sectional shape.

[0081] The solid aerosol-forming substrate may include a tobacco plug. The tobacco plug may include, for example, one or more of powder, granules, pellets, shreds, strands, strips, or sheets, including one or more of herb leaves, tobacco leaves, tobacco stems, expanded tobacco, and homogenized tobacco. The term "homogenized tobacco material" as used herein means a material formed by agglomerating particulate tobacco. Providing homogenized tobacco material may improve aerosol generation and the nicotine content and flavor profile of the aerosol generated during heating of the aerosol-generating article. Specifically, the process of making homogenized tobacco involves grinding tobacco leaves, which allows for more efficient release of nicotine and flavor upon heating. When the tobacco plug includes homogenized tobacco material, the homogenized tobacco material may be in the form of a sheet. As used herein, the term "sheet" means a layered element having a width and length substantially greater than its thickness.

[0082] The solid aerosol-forming substrate may comprise homogenized tobacco material. The solid aerosol-forming material may comprise pieces, strands, or strips of homogenized tobacco material. The solid aerosol-forming substrate may comprise a sheet of homogenized tobacco material.

[0083] The aerosol-forming substrate may have a substantially homogeneous composition.The aerosol-forming substrate may have a substantially homogeneous composition at least in the longitudinal direction.

[0084] The homogenized tobacco material sheet may be formed by agglomerating particulate tobacco obtained by grinding or otherwise comminuted one or both of tobacco lamina and tobacco stems. The homogenized tobacco material sheet may also include one or more of tobacco dust, tobacco fines, and other particulate tobacco by-products formed, for example, during tobacco processing, handling, and transportation. The homogenized tobacco material sheet is preferably formed by a casting process of the type that generally involves casting a slurry including particulate tobacco and one or more binders onto a conveyor belt or other support surface, drying the cast slurry to form a sheet of homogenized tobacco material, and removing the sheet of homogenized tobacco material from the support surface.

[0085] The solid aerosol-forming substrate may comprise an assembly of sheets of homogenized tobacco material. As used herein, the term "assembled" is used to describe a sheet that has been rolled, folded, or otherwise compressed or contracted substantially transverse to the longitudinal axis of the aerosol-generating article.

[0086] The aerosol-forming substrate comprises an assembly of textured sheets of homogenized tobacco material. As used herein, the term "textured sheets" refers to sheets that have been crimped, embossed, debossed, perforated, or otherwise deformed. The use of textured sheets of homogenized tobacco material may advantageously facilitate assembling the sheets of homogenized tobacco material to form the aerosol-forming substrate. The aerosol-forming substrate may comprise an assembly of textured sheets of homogenized tobacco material that include a plurality of spaced indentations, protrusions, perforations, or combinations thereof.

[0087] The aerosol-forming substrate preferably comprises an assembly of a crimped sheet of homogenized tobacco material. As used herein, the term "crimped sheet" refers to a sheet having a plurality of substantially parallel ridges or corrugations. The substantially parallel ridges or corrugations preferably extend along or parallel to the longitudinal axis of the aerosol-generating article. This advantageously facilitates collection of the crimped sheet of homogenized tobacco material for forming the aerosol-generating article. However, it is recognized that a crimped sheet of homogenized tobacco material for inclusion in an aerosol-generating article may have a plurality of substantially parallel ridges or corrugations that are disposed at an acute or obtuse angle to the longitudinal axis of the aerosol-generating article.

[0088] The aerosol-forming substrate may include tobacco-containing and non-tobacco-containing materials.

[0089] The aerosol-forming substrate may include an aerosol former. The aerosol-forming substrate may include a single aerosol former or a combination of two or more aerosol formers. As used herein, the term "aerosol former" is used to describe any suitable known compound or mixture of compounds that facilitates the formation of an aerosol when used and is substantially resistant to thermal decomposition at the operating temperature of the aerosol-generating article. Suitable aerosol formers include, but are not limited to, polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3-butanediol, and glycerin), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate and dimethyl tetradecanedioate). Preferred aerosol formers are polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3-butanediol, and most preferably glycerin) or mixtures thereof. The aerosol-forming substrate may have an aerosol former content of greater than 5 percent on a dry weight basis.The aerosol-forming substrate may have an aerosol former content of about 5 percent to about 30 percent on a dry weight basis.The aerosol-forming substrate may have an aerosol former content of about 20 percent on a dry weight basis.

[0090] The aerosol-forming substrate may include homogenized tobacco material, an aerosol former, and water.

[0091] The homogenized tobacco material may be provided in a sheet that is folded, crimped, or cut into strips. The sheet may be cut into strips having a width of about 0.2 millimeters to about 2 millimeters, more preferably about 0.4 millimeters to about 1.2 millimeters. The width of the strips may be about 0.9 millimeters.

[0092] The aerosol-forming substrate may include an internal cavity. In other words, the aerosol-forming substrate may be a tubular substrate. The aerosol-forming substrate may include an internal substrate surface having an internal substrate diameter, the internal substrate surface defining an internal cavity extending longitudinally within the aerosol-forming substrate. Providing an internal cavity within the aerosol-forming substrate may allow a heating element to be inserted within the cavity without penetrating the substrate and without modifying the substrate structure. Providing an internal cavity may also be beneficial to further reduce the thickness of the aerosol-forming substrate and enhance the heat transfer advantages discussed above.

[0093] Where the aerosol-forming substrate includes an inner substrate surface that bounds an internal cavity, the inner substrate surface may have the same transverse cross-sectional shape as the outer substrate surface, in particular the inner substrate surface may have a substantially circular, elliptical or stadium-shaped transverse cross-section.

[0094] The aerosol-generating article may comprise a layer of thermally conductive material. The layer of thermally conductive material may cover at least a portion of the aerosol-forming substrate that would otherwise be exposed. The layer of thermally conductive material may be disposed on at least the substrate outer surface. The layer of thermally conductive material may be disposed on at least the substrate inner surface. The layer of thermally conductive material may be disposed on at least the substrate inner surface and on the substrate outer surface. By providing a layer of thermally conductive material on an otherwise exposed substrate surface, heat from a heating element received by or engaged with the substrate may be distributed over a larger area of ​​the aerosol-forming substrate, improving the efficiency of heat transfer between the heating element and the aerosol-forming substrate. The layer of thermally conductive material may also create a physical separation between the heating element received in the internal cavity and the aerosol-forming substrate, which may reduce the risk of overheating the aerosol-forming substrate in an area of ​​the substrate near the heating element. The layer of thermally conductive material may also increase the robustness of the tubular aerosol-forming substrate, which may be reduced by the reduction in the thickness of the substrate due to the provision of an internal cavity.

[0095] As used herein, the term "thermally conductive" refers to a material having a thermal conductivity of at least 10 W / mK, preferably at least 40 W / mK, more preferably at least 100 W / mK at 23 degrees Celsius and 50% relative humidity. Preferably, the layer of thermally conductive material may comprise a material having a thermal conductivity of at least 40 W / mK, preferably at least 100 W / mK, more preferably at least 150 W / mK, even more preferably at least 200 W / mK at 23 degrees Celsius and 50% relative humidity.

[0096] Examples of suitable conductive materials include, but are not limited to, aluminum, copper, zinc, nickel, silver, and combinations thereof.

[0097] The aerosol-forming substrate may comprise a rod comprising a plurality of elongated tubular elements. The elongated tubular elements may comprise tobacco material. The plurality of elongated tubular elements comprised in the aerosol-forming substrate should not be confused with tubular elements arranged downstream of the aerosol-forming substrate.

[0098] By adjusting the number, equivalent diameter and thickness of the elongated tubular elements of the rod, it may be advantageously possible to adjust the density and porosity of the rod. In general, an aerosol-forming substrate comprising a plurality of elongated tubular elements of homogenized tobacco may advantageously exhibit a more uniform density than an aerosol-forming substrate comprising pieces of tobacco material. The geometric shape of the elongated tubular elements may be such that a particularly stable channel is provided for the airflow along the rod. This may advantageously allow for consistent fine-tuning of the RTD, so that aerosol-forming substrates with a given RTD can be produced in a consistent manner and with great precision.

[0099] The weight of an aerosol-forming substrate comprising elongated tubular elements of homogenized tobacco may be determined by the number, size, density and spacing of the tubular elements, which may reduce the weight discrepancy between aerosol-forming substrates of the same dimensions, resulting in a lower rejection rate of aerosol-forming substrates whose weight is outside a selected tolerance range, compared to aerosol-forming substrates comprising pieces of tobacco material.

[0100] Varying the thickness of the elongated tubular elements in the rod may also be advantageously used to adjust the homogenized tobacco content in the rod. For example, in elongated tubular elements formed from rolled strips of homogenized tobacco web, adjusting the thickness of the elongated tubular elements may be achieved by varying the number of times the strip is rolled about its longitudinal axis, or by varying the thickness of the homogenized tobacco web itself. This may allow for greater design flexibility compared to aerosol-generating articles that include pieces of tobacco material.

[0101] The size, geometry and arrangement of the elongated tubular elements in the rod can be easily adapted to facilitate the insertion of a heating element into the rod of the aerosol-generating article. The tubular elements lie substantially straight within the rod and extend longitudinally, which can facilitate the insertion of a longitudinally extending internal heating element (such as a heater blade). A regular arrangement of the elongated tubular elements in the rod can also advantageously favor the optimization of heat transfer from the heating element through the rod.

[0102] Insertion of the heater of the aerosol-generating device into (and removal of the heater from) an aerosol-forming substrate containing pieces of tobacco material may tend to cause pieces of tobacco material to flake off from the aerosol-forming substrate. This may require more frequent cleaning of the heater element and other parts of the aerosol-generating device to remove the flakes. In contrast, insertion of the heater of the aerosol-generating device into (and removal of) an aerosol-forming substrate comprising a plurality of elongated tubular elements of homogenized tobacco material may advantageously significantly reduce the tendency for material to flake off.

[0103] A rod comprising a plurality of elongated tubular elements can be made in a continuous process that can be performed quickly and efficiently and can be conveniently integrated into existing production lines for the manufacture of aerosol-generating articles.

[0104] The rod of aerosol-forming substrate may preferably have an outer diameter approximately equal to the outer diameter of the aerosol-generating article.

[0105] The rod of the aerosol-forming substrate may have an outer diameter of at least 5 millimeters. The rod of the aerosol-forming substrate 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. Preferably, the rod of the aerosol-forming substrate may have an outer diameter of 7.2 millimeters ±10 percent.

[0106] The rod of the aerosol-forming substrate may have a length of about 5 mm to about 100 mm. Preferably, the rod of the aerosol-generating substrate may have a length of at least about 5 mm, more preferably at least about 7 mm. The rod of the aerosol-generating substrate may have a length of preferably less than about 80 mm, more preferably less than about 65 mm, even more preferably less than about 50 mm. Preferably, the rod of the aerosol-generating substrate may have a length of less than about 35 mm, more preferably less than 25 mm, even more preferably less than about 20 mm. The rod of the aerosol-forming substrate may have a length of about 10 mm, and the rod of the aerosol-forming substrate may have a length of about 12 mm.

[0107] The rod of the aerosol-forming substrate may have a substantially uniform cross-section along the length of the rod. It may be preferred that the rod of the aerosol-forming substrate has a substantially circular cross-section.

[0108] The rod comprising the elongate tubular elements may be surrounded by a wrapper. The elongate tubular elements may be assembled such that the elongate tubular elements extend longitudinally.

[0109] The plurality of elongated tubular elements of the rod of the aerosol-generating article according to the invention may be formed of a homogenous tobacco material, which may include particulate tobacco obtained by grinding. The plurality of elongated tubular elements may all have substantially the same composition as each other. Similarly, the plurality of elongated tubular elements may include tubular elements of at least two different compositions.

[0110] At least one elongated tubular element in the rod may comprise a rolled strip cut from a sheet or web of homogenized tobacco material.

[0111] The sheet or web of homogenized tobacco material may have a tobacco content of at least about 40 weight percent on a dry weight basis, more preferably at least about 60 weight percent on a dry weight basis, more preferably or at least about 70 weight percent on a dry weight basis, and most preferably at least about 90 weight percent on a dry weight basis.

[0112] A sheet or web of homogenized tobacco material for use in an aerosol-forming substrate may include one or more intrinsic binders (i.e., tobacco intrinsic binders), one or more extrinsic binders (i.e., tobacco extrinsic binders), or combinations thereof, to aid in agglomerating the particulate tobacco. A sheet of homogenized tobacco material for use in an aerosol-forming substrate may include other additives, including, but not limited to, tobacco and non-tobacco fibers, aerosol formers, humectants, plasticizers, flavorants, fillers, aqueous and non-aqueous solvents, and combinations thereof.

[0113] Suitable extrinsic binders for inclusion in sheets or webs of homogenized tobacco material for use in aerosol-forming substrates are known in the art and include, but are not limited to, gums (e.g., guar gum, xanthan gum, gum arabic, locust bean gum, etc.), cellulosic binders (e.g., hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, and ethyl cellulose, etc.), polysaccharides (e.g., starch, organic acids (e.g., alginic acid), conjugate base salts of organic acids (e.g., sodium alginate), agar, pectin, etc.), and combinations thereof.

[0114] Suitable non-tobacco fibers for inclusion in a sheet or web of homogenized tobacco material for use in an aerosol-forming substrate are known in the art and include, but are not limited to, cellulose fibers, softwood fibers, hardwood fibers, jute fibers, and combinations thereof. Prior to inclusion in a sheet of homogenized tobacco material for use in an aerosol-forming substrate, the non-tobacco fibers may be treated by any suitable process known in the art, including, but not limited to, mechanical pulping, refining, chemical pulping, bleaching, sulfate pulping, and combinations thereof.

[0115] The sheet or web of homogenized tobacco material may include an aerosol former.

[0116] Homogenized tobacco sheets or webs for use in the aerosol-generating articles of the invention may be made by methods known in the art, such as the methods disclosed in WO-A-2012 / 164009 A2. Sheets of homogenized tobacco material for use in the aerosol-generating articles may be formed from a slurry comprising particulate tobacco, guar gum, cellulose fibers, and glycerin by a casting process.

[0117] Alternatively, the elongated tubular elements of homogenized tobacco material for use in the aerosol-forming substrate according to the invention may be formed by extrusion. By way of example, a slurry containing particulate tobacco obtained by grinding or otherwise comminuted tobacco lamina may be forced through a die of the desired cross-section. Furthermore, additive manufacturing may also be used to produce the tubular elements of homogenized tobacco material.

[0118] The elongate tubular elements may have an equivalent diameter of about 0.03 millimeters to about 3 millimeters. Preferably, the elongate tubular elements may have an equivalent diameter of at least about 0.1 millimeters. More preferably, the elongate tubular elements may have an equivalent diameter of at least about 0.3 millimeters.

[0119] Similarly, the elongate tubular elements may preferably have an equivalent diameter of less than about 2 millimeters. More preferably, the elongate tubular elements may have an equivalent diameter of less than about 1 millimeter.

[0120] The elongate tubular element may have an equivalent diameter of about 0.7 millimeters to about 2.7 millimeters, and the elongate tubular element may have an equivalent diameter of about 0.3 millimeters to about 1.1 millimeters.

[0121] When the elongated tubular elements are formed by rolling strips of homogenized tobacco material, the strips may have a width of at least about 1 millimeter. Preferably, the strips of homogenized tobacco material may have a width of at least about 2 millimeters. More preferably, the strips of homogenized material may have a width of at least about 3 millimeters.

[0122] The homogenized tobacco material strips may have a width of from about 1 millimeter to about 3.5 millimeters, and the homogenized tobacco material strips may have a width of from about 2.4 millimeters to about 8.2 millimeters.

[0123] The homogenized tobacco material strips may be cut from a sheet or web having a thickness of at least about 40 microns, more preferably at least about 60 microns, more preferably at least about 80 microns, and most preferably at least about 100 microns. Similarly, the homogenized tobacco material strips may be cut from a sheet or web having a thickness of about 5000 microns or less, more preferably about 2000 microns or less, more preferably about 1000 microns or less, and most preferably about 500 microns or less. For example, the thickness of the sheet or web may be about 40 microns to about 5000 microns, more preferably about 60 microns to about 2000 microns, more preferably about 80 microns to about 1000 microns, and most preferably about 100 microns to about 500 microns.

[0124] The thickness of the elongate tubular element may be at least about 40 microns, more preferably at least about 80 microns, more preferably at least about 120 microns, and most preferably at least about 160 microns. Similarly, the thickness of the elongate tubular element may be less than about 5000 microns, more preferably less than about 2500 microns, and most preferably less than about 1000 microns.

[0125] The elongated tubular elements may be formed of porous tobacco material so as to allow air to flow through the walls of the tubular elements, i.e. so that air flow along a substantially radial direction in the rod is unimpeded. Where the elongated tubular elements are formed by rolling strips of homogenized tobacco material, the strips themselves may be formed of porous tobacco material.

[0126] The term "porous" as used herein in relation to homogenized tobacco material may indicate that the tobacco material has been produced within a range of inherent porosity such that sufficient pores or gaps are provided within the structure of the sheet or web to allow air flow through the sheet or web in a direction transverse to the surface of the sheet or web. Similarly, the term "porous" may indicate that each sheet or web of tobacco material comprises a plurality of airflow holes to provide the desired porosity. For example, a sheet of tobacco material may be perforated with a pattern of airflow holes before a rolling operation is performed to generate the elongated tubular element of the rod of aerosol-forming substrate. The airflow holes may be perforated randomly or uniformly across the sheet. The pattern of airflow holes may cover substantially the entire surface of the sheet, or may cover one or more specific areas of the sheet, with the remaining areas being devoid of airflow holes.

[0127] The strips of homogenized tobacco material from which the elongated tubular elements may be formed may be textured. For example, the sheet or web from which the strips are cut may comprise a plurality of spaced apart indentations, protrusions, perforations, or combinations thereof. The texture may be provided on one side of each sheet, or on both sides of each sheet.

[0128] The inclusion of one or more elongated tubular elements formed from the crimped strip can help to provide and maintain some spacing between adjacent tubular elements within the rod.

[0129] The additive may be applied to at least a portion of the surface of at least one of the plurality of tubular elements. The additive may be a solid additive, a liquid additive, or a combination of solid and liquid additives. Suitable solid and liquid additives for use in the present invention are known in the art and include, but are not limited to, flavorants (e.g., menthol, etc.), adsorbents (e.g., activated carbon, etc.), fillers (e.g., calcium carbonate, etc.), and botanical additives.

[0130] To form a substantially elongated tubular element, the strip of homogenized tobacco material may be wrapped at least about 345 degrees about the longitudinal axis. Preferably, the strip of homogenized tobacco material may be wrapped at least about 360 degrees about the longitudinal axis. More preferably, the strip of homogenized tobacco material may be wrapped at least about 540 degrees about the longitudinal axis. Similarly, the strip of homogenized tobacco material may preferably be wrapped less than about 1800 degrees about the longitudinal axis. More preferably, the strip of homogenized tobacco material may be wrapped less than about 900 degrees about the longitudinal axis. Preferably, the strip of homogenized tobacco material may be wrapped between about 345 degrees and about 540 degrees about the longitudinal axis.

[0131] Each elongate tubular element may have a length substantially equal to the length of the rod of the aerosol-forming substrate. Each elongate tubular element may have a length of about 10 millimeters, and each elongate tubular element may be about 12 millimeters long.

[0132] The rod of the aerosol-forming substrate may comprise less than about 200 elongated tubular elements of homogenized tobacco material. More preferably, the rod of the aerosol-forming substrate may comprise less than about 150 elongated tubular elements. Even more preferably, the rod of the aerosol-forming substrate may comprise less than about 100 elongated tubular elements.

[0133] Similarly, the rod of the aerosol-forming substrate may comprise at least about 15 elongated tubular elements of homogenized tobacco material. Even more preferably, the rod of the aerosol-forming substrate may comprise at least about 30 elongated tubular elements. Even more preferably, the rod of the aerosol-forming substrate may comprise at least about 40 elongated tubular elements. The rod of the aerosol-forming substrate may comprise from about 15 to about 100 strands of non-tobacco material.

[0134] In the rod of the aerosol-forming substrate, the elongated tubular elements may be aligned substantially parallel to one another.

[0135] The elongated tubular element of homogenized tobacco material may have a substantially oval cross-section, a substantially elliptical cross-section, or a substantially circular cross-section. As noted above, the elongated tubular element for use in the aerosol-generating article may be effectively formed by wrapping a strip of homogenized tobacco material slightly less than 360 degrees around its longitudinal axis. This results in an element that effectively has a C-shaped cross-section, with a slit running longitudinally the entire length of the elongated tubular element.

[0136] An aerosol generating system is also provided, which may comprise any of the aerosol generating articles disclosed above and an aerosol generating device, which may comprise a heating element or part of a heating element for heating the aerosol generating article.

[0137] As used herein, the term "aerosol generating system" refers to the combination of an aerosol generating device and an aerosol generating article.

[0138] Since the aerosol generating system of the present disclosure comprises an aerosol generating article according to the above disclosure, the advantages discussed above for the aerosol generating article also apply to the system itself.

[0139] The heating element may be any suitable type of heating element. The heating element may be an internal heating element. The heating element may be an elongated heating element. The elongated heating element may be blade-shaped. The elongated heating element may be pin-shaped. The elongated heating element may be tapered, or at least have a tapered end. The elongated heating element may have a pointed end. The heating element may be cone-shaped. The elongated heating element may have any suitable shape arranged to facilitate insertion of the heating element into the aerosol-forming substrate. Advantageously, an elongated heating element may provide easier engagement or disengagement, or both easier engagement and easier disengagement, of the heating element of the device with the aerosol-generating article.

[0140] The heating element may be an external heating element. As used herein, the term "external heating element" refers to a heating element configured to heat the outer surface of the aerosol-forming substrate. The external heating element may at least partially surround the cavity for receiving the aerosol-forming substrate.

[0141] The heating element may include at least one resistive heating element.

[0142] At least one resistive heating element may include an electrically insulating substrate and one or more conductive tracks on the electrically insulating substrate.

[0143] The electrically insulating substrate may be stable at the operating temperature of the at least one heating element. The electrically insulating substrate may be stable at temperatures up to about 400 degrees Celsius, more preferably about 500 degrees Celsius, more preferably about 600 degrees Celsius, more preferably about 700 degrees Celsius, and most preferably about 800 degrees Celsius.

[0144] The operating temperature of the at least one resistive heating element during use may be at least about 200 degrees Celsius. The operating temperature of the at least one resistive heating element during use may be less than about 700 degrees Celsius. The operating temperature of the at least one resistive heating element during use may be less than about 600 degrees Celsius. The operating temperature of the at least one resistive heating element during use may be less than about 500 degrees Celsius. The operating temperature of the at least one resistive heating element during use may be less than about 400 degrees Celsius.

[0145] The electrically insulating substrate may comprise any suitable material. For example, the electrically insulating substrate may comprise one or more of paper, glass, ceramic, anodized metal, coated metal, and polyimide. Ceramics include mica, alumina (Al 2 O 3 ) or zirconia (ZrO 2) The electrically insulating substrate may have a thermal conductivity of about 40 Watts / meter Kelvin or less, preferably about 20 Watts / meter Kelvin or less, and ideally about 2 Watts / meter Kelvin or less.

[0146] Suitable materials for forming the resistive heating element, and in particular the one or more conductive tracks, include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys, and composites made of ceramic and metallic materials. Such composites may include doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel-containing, cobalt-containing, chromium-containing, aluminum-containing, titanium-containing, zirconium-containing, hafnium-containing, niobium-containing, molybdenum-containing, tantalum-containing, tungsten-containing, tin-containing, gallium-containing, manganese-containing, and iron-containing alloys, as well as nickel-, iron-, cobalt-, and stainless steel-based superalloys, Timetal®, and iron-manganese-aluminum-based alloys.

[0147] The resistive heating elements may include one or more stamped sections of an electrically resistive material, such as stainless steel. At least one resistive heating element may include a heating wire or filament, such as a Ni-Cr (nickel-chromium), platinum, tungsten, or alloy wire.

[0148] The heating element may include at least one induction heating arrangement.

[0149] The at least one induction heating arrangement may include at least one inductor coil. The inductor coil is arranged to generate a varying magnetic field upon receiving a varying current from a power source. Such varying current may be from about 5 kilohertz to about 500 kilohertz. The varying current may be a high frequency varying current. As used herein, the term "high frequency varying current" refers to a varying current having a frequency of from about 500 kilohertz to about 30 megahertz. The high frequency varying current may have a frequency of from about 1 megahertz to about 30 megahertz (such as from about 1 megahertz to about 10 megahertz, or from about 5 megahertz to about 8 megahertz). The varying current may be an alternating current that generates an alternating magnetic field.

[0150] The inductor coil may have any suitable form. For example, the inductor coil may be a flat inductor coil. The flat inductor coil may be helically wound in a substantially plane. Preferably, the inductor coil may be a tubular inductor coil. Typically, the tubular inductor coil may be helically wound about a longitudinal axis. The inductor coil may be elongated. Particularly preferably, the inductor coil may be an elongated tubular inductor coil. The inductor coil may have any suitable cross-section. The inductor coil may have a circular, elliptical, square, rectangular, triangular, or other polygonal cross-section.

[0151] The inductor coil may be formed from any suitable material. The inductor coil may be formed from a conductive material. Preferably, the inductor coil may be formed from a metal or metal alloy.

[0152] As used herein, "conductivity" refers to a resistance greater than 1×10 at 20 degrees Celsius -4 Refers to materials that have an electrical resistivity of less than or equal to the ohm-meter (Ω·m).

[0153] The at least one induction heating arrangement may include at least one susceptor. As discussed above, a susceptor may also be included in the aerosol-generating article.

[0154] The susceptor may be arranged such that when the aerosol-generating article is received in the aerosol generating device, the oscillating electromagnetic field generated by the inductor coil induces a current in the susceptor, heating the susceptor. The aerosol generating device is preferably capable of generating an alternating electromagnetic field having a magnetic field strength (H field strength) of 1 to 5 kiloamperes per meter (kA / m), preferably 2 to 3 kA / m, for example about 2.5 kA / m. The aerosol generating device is preferably capable of generating an alternating electromagnetic field having a frequency of 1 to 30 MHz, for example 1 to 10 MHz, for example 5 to 7 MHz.

[0155] The susceptor may comprise any suitable material. The susceptor may be formed from any material that can be inductively heated to a temperature sufficient to release volatile compounds from the aerosol-forming substrate or flavor substrate. A preferred susceptor may be heated to a temperature greater than about 250 degrees Celsius. A preferred susceptor may be formed from an electrically conductive material. Suitable materials for the susceptor include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium, and composites of metallic materials. A preferred susceptor may comprise metal or carbon. Some preferred susceptors may comprise ferromagnetic materials, such as, for example, ferritic iron, ferromagnetic alloys, such as ferromagnetic steel or stainless steel, ferromagnetic particles, and ferrites. Some preferred susceptors may be comprised of ferromagnetic materials. A preferred susceptor may comprise aluminum. A preferred susceptor may be comprised of aluminum. The susceptor may include at least about 5 percent, at least about 20 percent, at least about 50 percent, or at least about 90 percent of a ferromagnetic or paramagnetic material.

[0156] The susceptor may be formed from a material that is substantially impermeable to gas, or, in other words, the susceptor may be preferably formed from a material that is not gas permeable.

[0157] The susceptor may have any suitable shape. For example, the susceptor may be elongated. The susceptor may have any suitable cross-section. For example, the susceptor may have a circular, oval, square, rectangular, triangular, or other polygonal cross-section. The susceptor may be tubular.

[0158] The susceptor may include a susceptor layer provided on a support. Placing the susceptor in a varying magnetic field induces eddy currents adjacent to the susceptor surface, resulting in an effect called the skin effect. Thus, the susceptor can be formed from a relatively thin layer of susceptor material while ensuring that the susceptor is effectively heated in the presence of the varying magnetic field. Making the susceptor from a support and a relatively thin susceptor layer can facilitate the manufacture of a simple, inexpensive and robust aerosol-generating article.

[0159] The support may be formed from a material that is not susceptible to inductive heating, which may advantageously reduce heating of the surface of the susceptor that is not in contact with the aerosol-forming substrate, where the surface of the support forms the surface of the susceptor that is not in contact with the aerosol-forming substrate.

[0160] The support may comprise an electrically insulating material. As used herein, "electrically insulating" means having a thermal conductivity of at least 1×10 at 20 degrees Celsius. 4 Refers to a material that has an electrical resistivity in ohmmeters (Ωm).

[0161] Forming the support from an insulating material can provide an insulating barrier between the susceptor layer and other components of the induction heating arrangement, such as the inductor coil that surrounds the induction heating element, which can advantageously reduce heat transfer between the susceptor and other components of the induction heating system.

[0162] The insulating material may also have a bulk thermal diffusivity of about 0.01 square centimeters per second (cm2 / s) or less, as measured using a laser flash method. Providing a support with such a thermal diffusivity may result in a support with high thermal inertia, which may reduce heat transfer between the susceptor layer and the support and reduce fluctuations in the temperature of the support.

[0163] The susceptor may include a protective outer layer, such as a protective ceramic or glass layer. The protective outer layer may improve the durability of the susceptor and facilitate cleaning of the susceptor. The protective outer layer may substantially surround the susceptor. The susceptor may include a protective coating formed from glass, ceramic, or an inert metal.

[0164] When a susceptor is included in the aerosol generating device, the susceptor may be located within the device cavity. The susceptor may extend into the device cavity along the longitudinal axis of the device cavity. The susceptor may be elongated. The elongated susceptor may be blade-shaped. The elongated susceptor may be pin-shaped. The elongated susceptor may be tapered, or at least have a tapered end. The elongated susceptor may have a pointed end. The elongated element may be cone-shaped.

[0165] Where the susceptor is included in the aerosol-generating device, the susceptor may be an internal heating element configured to be at least partially inserted into an aerosol-forming substrate of the aerosol-generating article when the aerosol-generating article is received within the device cavity. Where the aerosol-forming substrate comprises an internal cavity, the susceptor may be configured to be at least partially inserted into the internal cavity of the aerosol-forming substrate when the aerosol-generating article is received within the device cavity.

[0166] The aerosol generating device may include a power source. The power source may be a DC voltage source. The power source may be a battery. For example, the power source may be a nickel metal hydride battery, a nickel cadmium battery, or a lithium-based battery (e.g., a lithium cobalt battery, a lithium iron phosphate battery, or a lithium polymer battery). The power source may be another form of charge storage device, such as a capacitor. The power source may require recharging and may have the capacity to store enough energy to use the aerosol generating device.

[0167] A power source may be electrically connected to the heater to provide power to the heating elements, such as the substrate heating element and the downstream heating element. When the heating elements receive power from the power source, the heating elements may generate heat. The power source may be configured to provide sufficient power to the heating elements to heat the aerosol-forming substrate to a temperature at which the volatile compound is released from the aerosol-forming substrate.

[0168] The aerosol generating device may comprise a housing. The housing may at least partially define a cavity for receiving the aerosol generating article.

[0169] The aerosol generating device may comprise at least one device air inlet in fluid communication with the cavity. When the aerosol generating device comprises a housing, the housing may at least partially define the at least one device air inlet. It may be desirable for the device air inlet to allow ambient air to be drawn into the upstream end of the aerosol-forming substrate.

[0170] The aerosol generating device may include a controller. The controller may be configured to control the power supply from the power source to the heating element. The controller may be any suitable controller. The controller may include any suitable electrical circuitry and electrical components. The controller may include a processor and a memory. The controller may include a microprocessor, which may be a programmable microprocessor.

[0171] The aerosol generating device may include a sensor for detecting airflow indicative of a user taking a puff. The airflow sensor may be an electromechanical device. The airflow sensor may be any of a mechanical device, an optical device, an opto-mechanical device, and a microelectromechanical system (MEMS) based sensor. The aerosol generating device may include a manually operable switch for a user to initiate a puff.

[0172] The aerosol generating device may include an indicator for indicating when the at least one heating element is activated. The indicator may include a light that is activated when the at least one heating element is activated.

[0173] The aerosol generating device may include at least one electrical connector. The at least one electrical connector may be configured to charge a power source. The at least one electrical connector may be configured to connect to another electrical device. The at least one electrical connector may include an outer plug or socket with at least one outer electrical contact that allows the aerosol generating device to be connected to another electrical device. For example, the aerosol generating device may include a USB plug or socket that allows the aerosol generating device to be connected to another USB-enabled device. For example, the USB plug or socket may allow the aerosol generating device to be connected to a USB charging device to charge a rechargeable power source within the aerosol generating device. The USB plug or socket may support data transfer to and / or from the aerosol generating device. Similarly, the aerosol generating device may be connected to a computer to transfer data to the device, such as a new heating profile for a new aerosol-generating article.

[0174] When the aerosol generating device comprises a USB plug or socket, the aerosol generating device may further comprise a removable cover for covering the USB plug or socket when not in use When the USB plug or socket is a USB plug, the USB plug may be selectively retractable within the device.

[0175] These and other features and advantages of the present invention will become more apparent in the light of the following detailed description of preferred embodiments, given by way of illustrative and non-limiting example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0176] [Figure 1] FIG. 1 shows a longitudinal cross-section of an aerosol-generating article comprising an embedded susceptor and a wrapper. [Figure 2a] FIG. 2a shows a cross-section of the aerosol-generating article of FIG. [Figure 2b] FIG. 2b shows a cross-section of the overlap region defined by the wrappers of the aerosol-generating article circled in FIG. 2a. [Diagram 3] FIG. 3 shows a longitudinal cross section of an aerosol-generating article comprising a tubular element and a filter. [Figure 4] FIG. 4 shows a longitudinal cross-section of an aerosol-generating article comprising an upstream element and an aerosol cooling element. [Diagram 5] FIG. 5 shows a longitudinal cross section of an aerosol generating system comprising an aerosol generating device and any of the aerosol-generating articles of FIGS. [Figure 6] FIG. 6 shows an external view of the aerosol generation system of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0177] The present invention is defined in the claims. However, below is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment or disclosure described herein.

[0178] Example 1 1. An aerosol-generating article comprising: an aerosol-forming substrate; a wrapper surrounding the aerosol-forming substrate; the wrapper defines an overlap region where the wrapper overlaps itself, the overlap region including a first section and a second section disposed externally over the first section; the second section includes a crease or score defining a folded section at one end of the wrapper; An aerosol-generating article, wherein the folded section is sandwiched between the first section and the second section. Example 2 2. The aerosol-generating article of claim 1, wherein an inner adhesive is disposed between the folded section and the first section. Example 3 An aerosol-generating article according to any one of Examples 1 and 2, wherein an outer adhesive is disposed between the folded section and the second section. Example 4 An aerosol-generating article according to any one of Examples 2 and 3, wherein the adhesive comprises one or more of gum arabic, natural or synthetic resin, starch and varnish. Example 5 An aerosol-generating article according to any one of Examples 1 to 4, further comprising a heating element embedded within the aerosol-forming substrate. Example 6 The aerosol-generating article according to Example 5, wherein the heating element is a susceptor. Example 7 An aerosol-generating article according to any one of Examples 5 and 6, wherein the heating element is completely surrounded by and extends along the entire length of the aerosol-forming substrate. Example 8 An aerosol-generating article according to any one of Examples 1 to 7, wherein the diameter of the aerosol-generating article is from about 3 mm to about 8 mm. Example 9 An aerosol-generating article according to any one of Examples 1 to 8, wherein the wrapper has a thickness of from about 60 micrometers to about 200 micrometers, preferably from about 78 micrometers to about 160 micrometers, more preferably from 78 micrometers to about 140 micrometers, more preferably from about 100 micrometers to about 140 micrometers, and most preferably from about 125 micrometers to about 140 micrometers. Example 10 An aerosol-generating article according to any one of Examples 1 to 9, wherein the aerosol-forming substrate comprises one or more of tobacco, nicotine, a gel composition, and a flavor substrate. Example 11 An aerosol-generating article according to any one of Examples 1 to 10, wherein the wrapper has a basis weight of from about 10 grams per square meter to 28 grams per square meter, preferably from about 10 grams per square meter to 16 grams per square meter. Example 12 An aerosol-generating article according to any one of Examples 1 to 11, wherein the wrapper has a porosity of from about 30 to about 80 Coresta units, preferably from about 30 to 50 Coresta units, and most preferably from 30 to 40 Coresta units. Example 13 13. An aerosol-generating article according to any one of Examples 1 to 12, wherein the wrapper has a roughness of from about 50 Bekk seconds to about 1000 Bekk seconds, more preferably from about 100 Bekk seconds to about 200 Bekk seconds. Example 14 An aerosol-generating article according to any one of Examples 1 to 13, further comprising a filter arranged downstream of the aerosol-forming substrate. Example 15 An aerosol-generating article according to any one of Examples 1 to 14, further comprising a support element arranged downstream of the aerosol-forming substrate. Example 16 An aerosol-generating article according to Example 15, wherein the support element comprises a first hollow tubular segment. Example 17 17. The aerosol-generating article according to any one of Examples 15 and 16, wherein the support element is longitudinally disposed immediately downstream of the aerosol-forming substrate. Example 18 The aerosol-generating article of any one of Examples 15-17 when dependent on Example 14, wherein the filter is disposed longitudinally immediately downstream of the support element. Example 19 An aerosol-generating article according to any one of Examples 15-18, further comprising an aerosol cooling element longitudinally disposed downstream of the support element. Example 20 The aerosol-generating article according to example 19, wherein the aerosol cooling element comprises a second hollow tubular segment. Example 21 The aerosol-generating article according to any one of Examples 19 and 20 when dependent on Example 14, wherein the aerosol cooling element is disposed between the support element and the filter. Example 22 An aerosol-generating article according to any one of Examples 1 to 21, further comprising a mouthpiece disposed at a downstream end of the aerosol-generating article. Example 23 An aerosol-generating article according to any one of Examples 1 to 22, further comprising an upstream element disposed at an upstream end of the aerosol-generating article. Example 24 An aerosol-generating article according to any one of Examples 1 to 23, wherein the aerosol-forming substrate comprises a liquid component. Example 25 An aerosol-generating article according to any one of Examples 1 to 24, wherein the aerosol-forming substrate comprises a solid component. Example 26 An aerosol-generating article according to any one of Examples 1 to 25, wherein the aerosol-forming substrate comprises a plant-derived material, preferably a homogenized plant-derived material. Example 27 An aerosol-generating article according to any one of Examples 1 to 26, wherein the aerosol-forming substrate comprises a non-tobacco material. Example 28 An aerosol-generating article according to any one of Examples 1 to 27, wherein the aerosol-forming substrate comprises a solid homogenized tobacco material. Example 29 30. An aerosol-generating article according to example 29, wherein the aerosol-forming substrate comprises an assembly of at least one sheet of solid homogenized tobacco material. Example 30 30. The aerosol-generating article according to example 29, wherein at least one of the assembly of sheets comprises a textured sheet, a crinkled sheet, or both. Example 31 An aerosol-generating article according to any one of Examples 28 to 30, wherein the solid homogenized tobacco material comprises strips of tobacco material. Example 32 The aerosol-generating article according to any one of Examples 25 to 31 when dependent on Example 25, wherein the aerosol-forming substrate has a rod comprising a plurality of elongated tubular elements. Example 33 The aerosol-generating article according to Example 32 when dependent on Example 28, wherein the plurality of elongated tubular elements comprise solid homogenized tobacco material. Example 34 34. An aerosol-generating article according to example 33, wherein at least one elongated tubular material comprises a rolled strip cut from a sheet or web of solid homogenized tobacco material. Example 35 An aerosol-generating article according to any one of Examples 1 to 34, wherein the aerosol-forming substrate is a hollow tubular substrate defining an internal cavity. Example 36 An aerosol-generating article according to any one of Examples 1 to 35, further comprising a layer of thermally conductive material. Example 37 An aerosol-generating article according to any one of Examples 1 to 36, wherein the aerosol-forming substrate comprises an aerosol-forming body. Example 38 An aerosol generating device comprising a heating element or a portion of a heating element. Example 39 39. An aerosol generating device according to embodiment 38, wherein the heating element comprises at least one resistive heating element. Example 40 40. An aerosol generating device according to embodiment 39, wherein at least one resistive heating element comprises an electrically insulating substrate and one or more conductive tracks on the electrically insulating substrate. Example 41 An aerosol generating apparatus according to any one of Examples 38 to 40, wherein the heating element includes at least one induction heating arrangement, each induction heating arrangement including at least one inductor coil and, optionally, at least one susceptor. Example 42 42. An aerosol generating apparatus according to embodiment 41, wherein at least one inductor coil is arranged to generate a varying magnetic field upon receiving a varying current from a power source, the varying current being between about 5 kilohertz and about 500 kilohertz. Example 43 42. An aerosol generating apparatus according to embodiment 41, wherein at least one inductor coil is arranged to generate a varying magnetic field upon receiving a varying current from a power source, the varying current being between about 500 kilohertz and about 5 megahertz. Example 44 44. An aerosol generating device according to any one of Examples 41 to 43, wherein at least one inductor coil is a flat inductor coil, such as a flat inductor coil wound helically in a substantially plane. Example 45 44. The aerosol generating apparatus according to any one of Examples 41 to 43, wherein at least one inductor coil is a tubular inductor coil, such as a tubular inductor coil wound helically around the longitudinal axis. Example 46 An aerosol generating device according to any one of Examples 41 to 45, wherein at least one inductor coil is formed from a conductive material. Example 47 The aerosol-generating device according to any one of Examples 41 to 46, when dependent from Example 6, or when the aerosol-generating device comprises at least one susceptor, wherein the at least one susceptor is made of a conductive material. Example 48 An aerosol generating apparatus according to any one of Examples 41 to 47, depending on Example 6, wherein the at least one susceptor comprises a susceptor layer provided on a support, the support preferably comprising a thermally insulating material, or wherein the aerosol generating apparatus comprises at least one susceptor. Example 49 An aerosol generating apparatus according to any one of Examples 39 to 48, wherein the heating element comprises at least one resistive heating element and at least one inductive heating arrangement. Example 50 50. The aerosol generating device according to any one of Examples 38 to 49, wherein the heating element comprises an internal heating element. Example 51 The aerosol generating device according to any one of Examples 38 to 50, wherein the heating element comprises an external heating element. Example 52 An aerosol generating apparatus according to any one of Examples 38 to 51, further comprising a power source. Example 53 An aerosol generating device according to Example 52, wherein the power source is electrically connected to the heating element. Example 54 An aerosol generating device according to any one of Examples 38 to 53, further comprising a cavity for receiving an aerosol-generating article. Example 55 An aerosol generating device according to any one of Examples 38 to 54, further comprising a device housing. Example 56 An aerosol generating device according to examples 54 and 55, wherein the device housing at least partially defines a cavity for receiving an aerosol generating article. Example 57 An aerosol generating device according to any one of Examples 38 to 56, further comprising at least one device air inlet. Example 58 An aerosol generating device according to Example 57 when dependent on Example 55, wherein the device housing includes at least one device air inlet. Example 59 The aerosol-generating article of any one of Examples 38 to 58, further comprising a controller. Example 60 An aerosol-generating article according to any one of Examples 38 to 59, further comprising a sensor configured to detect airflow indicative of a user taking a puff. Example 61 The aerosol-generating article of any one of Examples 38-60, further comprising at least one electrical connector. Example 62 An aerosol-generating article according to example 61, wherein at least one electrical connector comprises an outer plug or socket, such as a USB plug or USB socket. Example 63 An aerosol generating system comprising an aerosol generating article according to any one of Examples 1 to 37 and an aerosol generating device according to any one of Examples 38 to 62.

[0179] 1 depicts a longitudinal cross-section of an aerosol-generating article 10 having an upstream end 13 and a downstream end 14, with the aerosol-generating article 10 defining a longitudinal axis between the upstream end 13 and the downstream end 14. The article 10 comprises an aerosol-forming substrate 11 and a wrapper 30 that surrounds the aerosol-forming substrate 11.

[0180] 1, the heating element 40 is embedded within the aerosol-forming substrate 11. The heating element 40 is a susceptor 40. The susceptor 40 extends along the entire length of the aerosol-forming substrate 11.

[0181] Figure 2a shows a cross-section of the aerosol-generating article 10 of Figure 1. This figure shows that the wrapper 30 defines an overlap region 41 where the wrapper 30 overlaps itself. The overlap region 41 includes a first section 42 and a second section 43 disposed externally on the first section 42. The second section 43 includes creases 44 (or scores) that define a folded section 45 at one end of the wrapper 40. The folded section 45 is sandwiched between the first section 42 and the second section 43.

[0182] An inner adhesive 50 is disposed between the folded section 45 and the first section 42. An outer adhesive 51 is disposed between the folded section 45 and the second section 43.

[0183] For clarity, the overlap region of FIG. 2a is shown in more detail in FIG. 2b.

[0184] FIG. 3 shows an aerosol-generating article comprising an aerosol-forming substrate 11 and a wrapper 30, similar to the aerosol-generating article of FIGS. 1 and 2. The aerosol-generating article 10 further comprises a support element 12 disposed immediately downstream of the aerosol-forming substrate 11. The tubular element 12 extends longitudinally and defines an opening adapted for substrate aerosol to flow towards a downstream end 14. In other words, the support element 12 comprises a hollow tubular segment. In the embodiment of FIG. 3, a filter 17 is disposed longitudinally immediately downstream of the support element 12. The wrapper 30 is identical to the wrapper 30 of the aerosol-generating article 10 of FIGS. 1 and 2. A susceptor 40 extends along the entire length of the aerosol-forming substrate 11.

[0185] Figure 4 shows an aerosol-generating article 10 comprising the wrapper 30 of Figures 1, 2 and 3. The aerosol-generating article 10 of Figure 4 is described below insofar as it differs from the aerosol-generating article 10 of Figures 1, 2 and 3.

[0186] The aerosol-generating article 10 of Figure 4 comprises a support element 12 located immediately downstream of the aerosol-forming substrate 11. In the embodiment of Figure 4, the upstream end of the support element 12 abuts the downstream end of the aerosol-forming substrate 11. In addition, the aerosol-generating article 10 comprises an aerosol-cooling element 15 located immediately downstream of the support element 22. In the embodiment of Figure 4, the upstream end of the aerosol-cooling element 15 abuts the downstream end of the support element 12.

[0187] The support element 12 includes a first hollow tubular segment. The aerosol cooling element 15 includes a second hollow tubular segment. The hollow tubular segment is provided in the form of a hollow cylindrical tube made of cellulose acetate. Other configurations in which the support element, the aerosol cooling element, or both do not include hollow tubular segments are also compatible with the embodiment of FIG.

[0188] 4 , the support element 12 and the aerosol cooling element 15 together define an intermediate hollow section of the aerosol-generating article 10. Overall, the intermediate hollow section is adapted to allow the substrate aerosol to flow towards the downstream end 14 and does not contribute substantially to the overall draw resistance of the aerosol-generating article 10.

[0189] In the embodiment of Figure 4, filter 17 is disposed longitudinally immediately downstream of aerosol cooling element 15. As shown in Figure 4, the upstream end of filter 17 abuts the downstream end of aerosol cooling element 15.

[0190] Filter 17 is provided in the form of a cylindrical plug of low density cellulose acetate.

[0191] 4, the aerosol-generating article 10 comprises an upstream element 16. The upstream element 16 abuts the upstream end of the aerosol-forming substrate 11. This advantageously prevents the susceptor 40 from becoming dislodged. Furthermore, this ensures that a consumer cannot accidentally come into contact with the heated susceptor 40 after use.

[0192] The upstream element 16 is provided in the form of a cylindrical plug of cellulose acetate.

[0193] In some non-illustrated examples of the embodiment of FIGS. 3 and 4, the aerosol-generating article 10 includes a mouthpiece located immediately downstream of the filter 17 .

[0194] 5 shows a schematic longitudinal cross-section of an aerosol generating system comprising an aerosol generating device 200 and an aerosol-generating article 10. The aerosol-generating article 10 may be any of the articles of FIGS.

[0195] The aerosol generating device 200 comprises a substantially cylindrical device housing 207 having a shape and size similar to a conventional cigar.

[0196] The aerosol generating device 200 further comprises a power source 201 in the form of a rechargeable nickel-cadmium battery, a controller 202 in the form of a printed circuit board including a microprocessor, an electrical connector 203 and a heating element 204. The heating element 204 is configured to heat the aerosol-forming substrate 11.

[0197] In the embodiment of Figure 5, the heating element 204 is an inductive heating arrangement 204 including at least one inductor coil 206 intended to cooperate with the susceptor 40 of the aerosol-generating article 10. However, other forms of heating elements may be used, such as a resistive heating element. Similarly, the inductive heating arrangement 204 may include a susceptor. The latter arrangement is preferred for use with aerosol-generating articles that do not include a susceptor.

[0198] The power supply 201, controller 202, and inductor coil 206 are all contained within a device housing 207. The inductor coil 206 of the aerosol generation device 200 is disposed at a proximal end of the device 200. The electrical connector 203 is disposed at a distal end of the device housing 207.

[0199] As used herein, the term "proximal" refers to the user end or oral end of an aerosol generating device or aerosol generating article. The proximal end of a component of an aerosol generating device or aerosol generating article is the end of the component closest to the user end or the oral end of the aerosol generating device or aerosol generating article. As used herein, the term "distal" refers to the end opposite the proximal end.

[0200] The controller 202 is configured to control the supply of power from the power source 201 to the inductor coil 206. The controller 202 further includes a DC / AC inverter including a class D power amplifier. The controller 202 is also configured to control the recharging of the power source 201 from the electrical connector 203. The controller 202 further includes a puff sensor (not shown) configured to detect when a user withdraws an aerosol-generating article received within the device cavity 208.

[0201] The inductor coil 206 is connected to the controller 202 and the power supply 201, and the controller 202 is configured to supply a varying current to the substrate inductor coil 206. When a varying current is supplied to the inductor coil 206, the inductor coil 206 generates a varying magnetic field, which heats the susceptor 40 by induction.

[0202] 6, the device housing 207 also defines a device air inlet 213 proximate a distal end of the cavity 208 for receiving the aerosol-generating article 10. The device air inlet 213 is configured to allow ambient air to be drawn into the device housing 207 towards the aerosol-forming substrate 11.

Claims

1. 1. An aerosol-generating article comprising: an aerosol-forming substrate; a wrapper surrounding the aerosol-forming substrate, the wrapper defines an overlap region where the wrapper overlaps itself, the overlap region including a first section and a second section disposed externally over the first section; the second section includes a crease defining a folded section at one end of the wrapper; the folded section is sandwiched between the first section and the second section; An outer adhesive is disposed between the folded section and the second section.

2. The aerosol-generating article of claim 1 , wherein an inner adhesive is disposed between the folded section and the first section.

3. 2. The aerosol-generating article of claim 1, wherein the adhesive comprises one or more of gum arabic, natural or synthetic resin, starch, and varnish.

4. 10. The aerosol-generating article of claim 1, further comprising a heating element embedded within the aerosol-forming substrate.

5. The aerosol-generating article of claim 4 , wherein the heating element is an induction susceptor.

6. 6. An aerosol-generating article according to claim 4, wherein the heating element is completely surrounded by the aerosol-forming substrate and extends along the entire length of the aerosol-forming substrate.

7. 6. An aerosol-generating article according to any one of claims 1 to 5, wherein the diameter of the aerosol-generating article is from about 3 mm to about 8 mm.

8. 6. The aerosol-generating article of any of claims 1 to 5, wherein the wrapper has a thickness of from about 60 micrometers to about 200 micrometers, preferably from about 78 micrometers to about 160 micrometers, more preferably from 78 micrometers to about 140 micrometers, more preferably from about 100 micrometers to about 140 micrometers, and most preferably from about 125 micrometers to about 140 micrometers.

9. The aerosol-generating article of any one of claims 1 to 5, wherein the aerosol-forming substrate comprises one or more of tobacco, nicotine, a gel composition, and a flavour substrate.

10. 6. The aerosol-generating article according to claim 1, further comprising a filter arranged downstream of the aerosol-forming substrate.

11. 6. An aerosol-generating article according to any one of claims 1 to 5, wherein the length of the aerosol-generating article is from about 30 mm to about 100 mm.

12. 1. An aerosol generation system comprising: An aerosol-generating article according to any one of claims 1 to 5, An aerosol generating system comprising an aerosol generating device.

13. 13. The aerosol generating system of claim 12, wherein the aerosol generating device comprises a resistive heating element.

14. The aerosol generation system of claim 12 , wherein the aerosol generator comprises an inductor coil.

Images