Stable wrapper for aerosol-generating articles

Abstract

The aerosol-generating article (10) includes an aerosol-generating substrate (12) containing nicotine and a first paper layer (50) disposed around the aerosol-generating substrate. The first paper layer has a first thickness / basis weight value. A second paper layer (20) is disposed around the first paper layer. The second paper layer has a second thickness / basis weight value. The first thickness / basis weight value is less than the second thickness / basis weight value.

Description

Technical Field

[0001] The present disclosure relates to a wrapper for use in a smoking article, the wrapper being at least two paper layers and may also be used with an aerosol generating substrate.

Background Art

[0002] Aerosol generating articles in which an aerosol generating substrate such as a tobacco-containing substrate is heated rather than burned are well known in the art. Typically, in such heated aerosol generating articles, the aerosol is generated by the transfer of heat from a heat source to an aerosol generating substrate or material physically separated therefrom, which aerosol generating substrate or material may be in contact with the heat source, or within the heat source, or around the heat source, or downstream of the heat source. During use of the aerosol generating article, volatile compounds are released from the aerosol generating substrate by heat transfer from the heat source and entrained in the air drawn through the aerosol generating article. The released compounds condense as they cool to form an aerosol.

[0003] The paper used to wrap the aerosol generating substrate can absorb aerosol formers, water, and other liquid compounds found in the mainstream smoke or aerosol passing through the aerosol generating article, or moisture or water around the paper. The absorbed liquid may stain or weaken the paper and also adversely affect the appearance and structural integrity of the aerosol generating article. Heated aerosol generating articles are particularly prone to wetting and breaking due to the high amount of aerosol formers in the aerosol generating substrates of these heated aerosol generating articles. Heated aerosol generating articles are particularly prone to expansion when aerosol components are absorbed by the wrapper, leading to difficult removal from the heating device. Heated aerosol generating articles are particularly prone to breakage when they are firmly received and then removed from the heating device.

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is desirable to provide a rolled aerosol generating substrate that is visually and mechanically stable for aerosol generating articles containing particularly high amounts of liquid or aerosol forming substances.

[0005] It is desirable to provide an aerosol generating article that includes a wrapper that does not expand by absorbing water or compounds contained in the aerosol generating substrate.

[0006] It is desirable to provide an aerosol generating article that includes a wrapper that provides a grease barrier to the grease compounds contained in the aerosol generating substrate.

[0007] Also, it is desirable that this wrapper does not affect the taste of the aerosol generated by the aerosol generating article.

[0008] Also, it is desirable that this wrapper does not easily burn when in proximity to the heating element.

[0009] The object of the present invention may be to at least partially solve one or more of the desirable technical advantages described above.

Means for Solving the Problems

[0010] According to the present disclosure, there is provided an aerosol generating article comprising an aerosol generating substrate including nicotine and a first paper layer disposed around the aerosol generating substrate. The first paper layer has a first thickness / grammage value. A second paper layer is disposed around the first paper layer. The second paper layer has a second thickness / grammage value. The first thickness / grammage value is smaller than the second thickness / grammage value.

[0011] According to the present disclosure, there is provided an aerosol generating article comprising an aerosol generating substrate comprising nicotine and at least about 10% aerosol former (including glycerin), and a first paper layer disposed around the aerosol generating substrate. The first paper layer has a first thickness / grammage value. A second paper layer is disposed around the first paper layer. The second paper layer has a second thickness / grammage value. The first thickness / grammage value is smaller than the second thickness / grammage value.

[0012] The first paper layer preferably has a thickness / grammage of about 1.2 micrometers / gsm or less. The total thickness of the first paper layer and the second paper layer is preferably 80 micrometers or less.

[0013] The paper layer preferably has a thickness / grammage within the range of about 1.0 micrometers / gsm to about 1.2 micrometers / gsm. The paper layer may have a thickness of less than about 50 micrometers, or less than about 40 micrometers. The wrapper comprises a paper layer having a grammage within the range of about 25 gsm to about 45 gsm, or about 35 gsm to about 40 gsm. The paper layer preferably has a grammage within the range of about 25 gsm to about 45 gsm and a thickness within the range of about 35 micrometers to about 50 micrometers.

[0014] The second paper layer preferably contains PVOH (polyvinyl alcohol) or silicon. The second paper layer may include a surface treatment containing PVOH or silicon. The addition of PVOH (polyvinyl alcohol) or silicon may improve the grease barrier properties of the second paper layer. The first paper layer may not contain PVOH (polyvinyl alcohol) or silicon.

[0015] The first paper layer may contain PVOH (polyvinyl alcohol) or silicon. The first paper layer may include a surface treatment containing PVOH or silicon. The addition of PVOH (polyvinyl alcohol) or silicon may improve the grease barrier properties of the first paper layer.

[0016] The term "silicon" refers to siloxane. Silicon or siloxane preferably includes polydimethylsiloxane.

[0017] The first paper layer may have a water contact angle of at least about 30 degrees. The first paper layer may have a water contact angle of at least about 35 degrees, or at least about 40 degrees.

[0018] The first paper layer preferably has a thickness / grammage of about 1.2 micrometers / gsm or less and a water contact angle of at least about 30 degrees. The first paper layer may have a water contact angle of at least about 35 degrees, or at least about 40 degrees.

[0019] The first paper layer preferably has a water contact angle of at least 30 degrees and a breaking elongation ratio of CD / MD of about 2.5 or less. The first paper layer may have a breaking elongation ratio of CD / MD of about 2.2 or less, or about 2 or less.

[0020] The first paper layer preferably has a water contact angle of at least 30 degrees and a negative result for at least one kit oil sample of the Tappi 559cm-02 classical method 2002. The first paper layer may have a negative result for at least 5 kit oil samples, or all 10 kit oil samples of the Tappi 559cm-02 classical method 2002.

[0021] The first paper layer preferably has a first water contact angle of at least 30 degrees, and the second paper layer preferably has a second water contact angle of at least 30 degrees. The total thickness of the first paper layer and the second paper layer may be less than about 80 micrometers.

[0022] The first paper layer has a thickness / grammage of about 1.2 micrometers / gsm or less, and the second paper layer preferably contains PVOH or silicon. The total thickness of the first paper layer and the second paper layer is preferably 80 micrometers or less.

[0023] Preferably, the aerosol generating substrate may contain a homogenized tobacco material. The homogenized tobacco material of the tobacco may contain a tobacco material, about 1% to about 5% of a binder, and about 5% to about 30% of an aerosol former on a dry weight basis.

[0024] Preferably, the aerosol generating substrate may contain a gel composition. The gel composition may contain a large amount (by weight) of glycerin. The gel composition may contain xanthan gum.

[0025] Preferably, the aerosol generating substrate may contain a metal induction heating element. The metal induction heating element may contain a plurality of metal induction heating elements. The metal induction heating element may contain a metal induction heating ring element.

[0026] The first paper layer may have the specific characteristics described herein, and the second paper layer may be regarded as a conventional paper layer. The second paper layer may preferably be disposed outside the first paper layer. Alternatively, the first paper layer may be disposed outside the second paper layer. The first paper layer having the specific characteristics described herein is preferably in contact with the aerosol forming substrate.

[0027] The first paper layer may have the specific characteristics described herein, and the second paper layer may also have the specific characteristics described herein. In particular, the first paper layer may have the specific characteristics described herein, and the second paper layer may be a conventional paper additionally containing PVOH (polyvinyl alcohol) or silicon, and the total thickness of the first paper layer and the second paper layer is about 80 micrometers or less.

[0028] The first paper layer preferably covers at least 20%, at least 50%, at least 80%, at least 90%, at least 95%, at least 99%, or preferably substantially the entire length (the entire length) of the aerosol generating substrate. The first paper layer preferably covers the entire aerosol generating substrate and does not extend beyond the aerosol generating substrate.

[0029] Advantageously, the aerosol-generating article comprises at least two paper wrappers, wherein the first wrapper, or the second wrapper, or the first and second wrappers may reduce the wetting or absorption of water, wetting agent, or grease in the smoke or aerosol passing through the aerosol-generating article. As a result, even when a high amount of wetting agent is contained in the aerosol-generating substrate, expansion, visible soiling, and physical weakening of the wrapper portion of the aerosol-generating article may be reduced.

[0030] In particular, a paper layer having a paper thickness / grammage of about 1.2 micrometers / gsm or less exhibits a reduction in paper expansion. A paper wrapper having a paper thickness / grammage of about 1 micrometer / gsm or less preferably exhibits a reduction in paper expansion.

[0031] Advantageously, the aerosol-generating article provides a rolled aerosol-generating substrate that is visually and mechanically stable and avoids expansion. This is particularly useful for heat-not-burn aerosol-generating articles that may be inserted into a heating device. The aerosol-generating article wrapper is resistant to combustion when in proximity to the heating element, and thus the inductive heating element may be incorporated throughout the aerosol-generating substrate.

[0032] The term "aerosol-generating article" is used herein to mean an article in which an aerosol-generating substrate is heated to generate an inhalable aerosol and deliver it to a consumer. The term "aerosol-generating substrate" as used herein means a substrate having the ability to release volatile compounds upon heating to generate an aerosol.

[0033] Conventional cigarettes are ignited when the user applies a flame to one end of the cigarette and draws air through the other end. The localized heat generated by the flame and the oxygen in the air drawn through the cigarette ignites the end of the cigarette, and the resulting combustion generates inhalable smoke. In contrast, in a heat-not-burn aerosol generating article, the aerosol is generated by heating a flavor generating substrate (such as tobacco). Well-known heat-not-burn aerosol generating articles include, for example, electrically heated aerosol generating articles and aerosol generating articles in which the aerosol is generated by the transfer of heat from a combustible fuel element or heat source to an aerosol forming substrate physically separated therefrom. For example, the aerosol generating article according to the present disclosure has a particular use in an aerosol generating system comprising an electrically heated aerosol generating device having an internal heater blade adapted to be inserted into a rod of an aerosol generating substrate. This type of aerosol generating article is described in the prior art, for example, European Patent No. EP0822670.

[0034] As used herein, the term "aerosol generating device" refers to a device comprising a heater element that interacts with an aerosol generating substrate of an aerosol generating article to generate an aerosol.

[0035] As used herein, the term "aerosol generating system" refers to a combination of an aerosol generating device and an aerosol generating article.

[0036] The term "aerosol generating substrate" refers to a substance having the ability to generate or release an aerosol. The aerosol generating substrate may be a solid, paste, gel, slurry, liquid, or may include any combination of solid, paste, gel, slurry, and liquid compounds. The aerosol generating substrate is preferably a solid or a gel composition. The aerosol generating substrate preferably may contain nicotine.

[0037] The aerosol-generating article may comprise an aerosol-generating substrate and a mouthpiece. The mouthpiece may comprise a filter. The tipping wrapper may attach the filter to the aerosol-generating substrate.

[0038] The aerosol-generating substrate may be a solid composition. This composition may contain plant-based materials. The aerosol-generating substrate may contain tobacco, and preferably the tobacco contains volatile tobacco flavor compounds released from the aerosol-generating substrate upon heating. The aerosol-generating substrate may contain a homogenized tobacco material, an aerosol former, and a binder.

[0039] Nicotine may be present in the aerosol-generating substrate in the range of about 0.5 to about 10% by weight of nicotine, or about 0.5 to about 5% by weight of nicotine. Preferably, the aerosol-generating substrate may contain about 1 to about 3% by weight of nicotine, or about 1.5 to about 2.5% by weight of nicotine, or about 2% by weight of nicotine.

[0040] The aerosol-generating substrate may contain a flavorant. The plant material provides a flavorant that may impart flavor to the taste of the aerosol generated by the aerosol-generating article. A flavorant is any natural or artificial compound that affects the sensory pungency quality of the aerosol. Non-limiting examples of flavorant sources include mint (such as peppermint and spearmint), coffee, tea, cinnamon, clove, cocoa, vanilla, eucalyptus, geranium, yuzu, and juniper, and combinations thereof.

[0041] The aerosol generating substrate may contain essential oil. The essential oil may provide a flavoring agent that may impart flavor to the taste of the aerosol generated by the aerosol generating article. Suitable essential oils include, but are not limited to, eugenol, peppermint oil, and spearmint oil. A preferred essential oil is eugenol. The essential oil may be present in the aerosol generating substrate in an amount of at least about 0.1% by weight, or at least about 0.5% by weight, or at least about 1% by weight. The essential oil may be present in the aerosol generating substrate in the range of about 0.1% by weight to about 10% by weight, or about 0.1% by weight to about 5% by weight, or about 0.5% by weight to about 2% by weight.

[0042] The aerosol generating substrate may contain a gel composition. The term "gel" refers to a solid at room temperature. In this context, "solid" means that the gel has a stable size and shape and does not flow. Room temperature in this context means 25 degrees Celsius. The gel may be defined as a substantially diluted cross-linked system that does not exhibit fluidity in the steady state. By weight, the gel may be mostly liquid, yet they behave like solids due to the three-dimensional cross-linked network within the liquid. The cross-linking within the fluid gives the gel its structure (hardness). In this way, the gel may be a dispersion of liquid molecules within a solid in which liquid particles are dispersed in a solid medium.

[0043] The gel composition may include a gelling agent that forms a solid medium, an aerosol former such as glycerin dispersed in the solid medium, and nicotine dispersed in the glycerin. The composition forms a stable gel phase. The gel composition may include at least two gelling agents that form a solid medium, glycerin dispersed in the solid medium, and nicotine dispersed in the glycerin. The composition forms a stable gel phase. The gel composition may include a thickening agent, a gelling agent that forms a solid medium, glycerin dispersed in the solid medium, and nicotine dispersed in the glycerin. The composition forms a stable gel phase. The gel composition may include nicotine, an aerosol former, a thickening agent, a hydrogen bond cross-linked gelling agent, and an ionic cross-linked gelling agent. The gel composition may further include a divalent cation.

[0044] The term "thickening agent" refers to a compound that increases the viscosity without causing gel formation and keeps the mixture in a fluid state or remains fluid when uniformly added in an amount of 0.3% by weight in a mixture of 50% by weight water / 50% by weight glycerin at 25°C. Preferably, the thickening agent, when uniformly added in an amount of 0.3% by weight in a mixture of 50% by weight water / 50% by weight glycerin at 25°C, at a shear rate of 0.1 s -1 without causing gel formation, increases the viscosity by at least 50 cPs, preferably by at least 200 cPs, preferably by at least 500 cPs, preferably by at least 1000 cPs, and keeps the mixture in a fluid state or remains fluid. Preferably, the thickening agent, when uniformly added in an amount of 0.3% by weight in a mixture of 50% by weight water / 50% by weight glycerin at 25°C, at a shear rate of 0.1 s -1 without causing gel formation, increases the viscosity to at least 2 times, or at least 5 times, or at least 10 times, or at least 100 times higher than before addition, and keeps the mixture in a fluid state or remains fluid.

[0045] The viscosity values listed in this specification can be measured using a Brookfield RVT viscometer, rotating the disk type RV#2 spindle at a speed of 6 revolutions per minute (rpm) at 25°C.

[0046] The term "gelling agent" refers to a compound that uniformly forms a solid medium or support matrix that causes a gel when added in an amount of about 0.3% by weight to a mixture of 50% by weight water / 50% by weight glycerin. Examples of gelling agents include, but are not limited to, hydrogen bond cross-linked gelling agents and ionic cross-linked gelling agents.

[0047] The term "hydrogen bond cross-linked gelling agent" refers to a gelling agent that forms non-covalent cross-linking bonds or physical cross-linking bonds through hydrogen bonds. A hydrogen bond is a type of intermolecular electrostatic dipole-dipole attraction rather than a covalent bond to a hydrogen atom. This results from the attraction between a hydrogen atom covalently bonded to an extremely electronegative atom such as an N, O, or F atom and another extremely electronegative atom.

[0048] The term "ionic cross-linked gelling agent" refers to a gelling agent that forms non-covalent cross-linking bonds or physical cross-linking bonds through ionic bonds. Ionic cross-linking involves the association of polymer chains through non-covalent interactions. When polyvalent molecules with opposite charges are electrostatically attracted to each other, a cross-linked polymer network is formed, resulting in the formation of a cross-linked network.

[0049] The gel composition comprises an aerosol former. Ideally, the aerosol former is substantially resistant to pyrolysis at the operating temperature of the associated aerosol generating device. Suitable aerosol formers include, but are not limited to, polyhydric alcohols (such as triethylene glycol, 1,3 - butanediol, glycerin), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate), and aliphatic esters of monocarboxylic acids, dicarboxylic acids, or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate). The polyhydric alcohol or a mixture thereof may be one or more of triethylene glycol, 1,3 - butanediol, and glycerin (glycerin or propane - 1,2,3 - triol) or polyethylene glycol. The aerosol former is preferably glycerin.

[0050] The gel composition may contain a large amount of aerosol former such as glycerin. The gel composition may contain a mixture of water and glycerin, where glycerin forms the majority (by weight) of the gel composition. Glycerin may form at least about 50% by weight of the gel composition. Glycerin may form at least about 60% by weight, or about 65% by weight, or about 70% by weight of the gel composition. Glycerin may form from about 70% to about 80% by weight of the gel composition. Glycerin may form from about 70% to about 75% by weight of the gel composition.

[0051] The gel composition preferably contains no water or only a low amount of water. When the gel composition contains no water or only a low amount of water, the gel composition may contain a higher amount of other compounds (such as aerosol formers, gelling agents, thickeners, nicotine). Also, a gel composition that contains no water or only a low amount of water is simpler and requires less energy for vaporization. An aerosol formed from a gel composition that contains no water or only a low amount of water may be perceived by the user as not being very hot. The gel composition preferably contains less than about 40% by weight of water, preferably less than about 30% by weight of water, preferably less than about 25% by weight of water. The gel composition may contain less than about 20% by weight, or less than about 15% by weight, or less than about 10% by weight, or less than about 5% by weight of water. In some cases, it may be preferable for the gel composition to contain some water. When the composition contains some water, the gel composition is more stable. The gel composition preferably contains at least about 1% by weight, or at least about 2% by weight, or at least about 5% by weight of water. The gel composition preferably contains at least about 10% by weight, or at least about 15% by weight of water. The gel composition preferably contains water in the range of about 15% to about 25% by weight.

[0052] The gel composition may contain a gelling agent that is a hydrogen bond cross-linked gelling agent and an ion cross-linked gelling agent. The gel composition may further contain a thickener. The gelling agent may form a solid medium in which the aerosol former may be dispersed. The gelling agent may form a solid medium in which the aerosol former and water may be dispersed. The thickener combined with the hydrogen bond cross-linked gelling agent and the ion cross-linked gelling agent surprisingly appears to support the solid medium and maintain the gel composition even when the gel composition contains a high amount of glycerin.

[0053] The gel composition may contain a gelling agent in the range of about 0.4 wt% to about 10 wt%. Preferably, the composition may contain a gelling agent in the range of about 0.5 wt% to about 8 wt%. Preferably, the composition may contain a gelling agent in the range of about 1 wt% to about 6 wt%. Preferably, the composition may contain a gelling agent in the range of about 2 wt% to about 4 wt%. Preferably, the composition may contain a gelling agent in the range of about 2 wt% to about 3 wt%.

[0054] The gel composition may contain a thickening agent in the range of about 0.2 wt% to about 5 wt%. A thickening agent in the range of about 0.5 wt% to about 3 wt% is preferred. A thickening agent in the range of about 0.5 wt% to about 2 wt% is preferred. A thickening agent in the range of about 1 wt% to about 2 wt% is preferred.

[0055] The gel composition may contain a thickening agent, a hydrogen bond cross-linked gelling agent, and an ionic cross-linked gelling agent, which are present in the gel composition in a total amount of about 1 wt% to about 8 wt%. Preferably, the gel composition may contain a thickening agent, a hydrogen bond cross-linked gelling agent, and an ionic cross-linked gelling agent, which are present in the gel composition in a total amount of about 2 wt% to about 6 wt%. Preferably, the gel composition may contain a thickening agent, a hydrogen bond cross-linked gelling agent, and an ionic cross-linked gelling agent, which are present in the gel composition in a total amount of about 3 wt% to about 5 wt%.

[0056] The gel composition may contain a thickening agent, a hydrogen bond cross-linked gelling agent, and an ionic cross-linked gelling agent, each independently present in the gel composition in the range of about 0.3 wt% to about 3 wt%. Preferably, the gel composition may contain a thickening agent, a hydrogen bond cross-linked gelling agent, and an ionic cross-linked gelling agent, each independently present in the gel composition in the range of about 0.5 wt% to about 2 wt%. Preferably, the gel composition may contain a thickening agent, a hydrogen bond cross-linked gelling agent, and an ionic cross-linked gelling agent, each independently present in the gel composition in the range of about 1 wt% to about 2 wt%.

[0057] The thickener may contain one or more of xanthan gum, carboxymethyl cellulose, microcrystalline cellulose, methyl cellulose, gum arabic, guar gum, lambda carrageenan, or starch. Preferably, the thickener may contain xanthan gum.

[0058] The gel composition may contain a thickener (such as xanthan gum) in the range of about 0.2% to about 5% by weight. Preferably, xanthan gum may be in the range of about 0.5% to about 3% by weight. Preferably, xanthan gum may be in the range of about 0.5% to about 2% by weight. Preferably, xanthan gum may be in the range of about 1% to about 2% by weight.

[0059] The hydrogen bond cross-linking gelling agent may contain one or more of galactomannan, gelatin, agarose, or konjac gum, or agar. In some cases, it is preferable that the hydrogen bond cross-linking gelling agent contains agar.

[0060] The gel composition may contain a hydrogen bond cross-linking gelling agent (such as agar) in the range of about 0.3% to about 5% by weight. Preferably, the composition may contain a hydrogen bond cross-linking gelling agent in the range of about 0.5% to about 3% by weight. Preferably, the composition may contain a hydrogen bond cross-linking gelling agent in the range of about 1% to about 2% by weight.

[0061] The ionic cross-linking gelling agent may contain low acyl gellan, pectin, kappa carrageenan, iota carrageenan or alginate. Preferably, the ionic cross-linking gelling agent may contain low acyl gellan.

[0062] The gel composition may contain an ionic cross-linking gelling agent (such as low acyl gellan) in the range of about 0.3% to about 5% by weight. Preferably, the composition may contain an ionic cross-linking gelling agent in the range of about 0.5% to about 3% by weight. Preferably, the composition may contain an ionic cross-linking gelling agent in the range of about 1% to about 2% by weight.

[0063] The gel composition may further contain one divalent cation. Preferably, the divalent cation may include calcium ions such as calcium lactate in the solution. The divalent cation (such as calcium ions) may assist in the gel formation of a composition containing a gelling agent such as an ionic crosslinking gelling agent. The ionic effect may assist in gel formation. The divalent cation may be present in the gel composition in the range of about 0.1% to about 1% by weight, or at about 0.5% by weight.

[0064] The gel composition may further contain an acid. The acid may include a carboxylic acid. The carboxylic acid may include a ketone group. Preferably, the carboxylic acid may include a ketone group having less than about 10 carbon atoms, or less than about 6 carbon atoms, or less than about 4 carbon atoms, such as levulinic acid or lactic acid. This carboxylic acid preferably has 3 carbon atoms (such as lactic acid). Surprisingly, lactic acid improves the stability of the gel composition even more than similar carboxylic acids. The carboxylic acid may assist in gel formation. The carboxylic acid may reduce the change in nicotine concentration within the gel composition during storage.

[0065] The gel composition may contain a carboxylic acid (such as lactic acid) in the range of about 0.1% to about 5% by weight. Preferably, the carboxylic acid may be in the range of about 0.5% to about 3% by weight. Preferably, the carboxylic acid may be in the range of about 0.5% to about 2% by weight. Preferably, the carboxylic acid may be in the range of about 1% to about 2% by weight.

[0066] Nicotine is contained in the gel composition. Nicotine may be added to the composition in free base form or in salt form. The gel composition may contain from about 0.5 to about 10% by weight of nicotine, or from about 0.5 to about 5% by weight of nicotine. Preferably, the gel composition may contain from about 1 to about 3% by weight of nicotine, or from about 1.5 to about 2.5% by weight of nicotine, or about 2% by weight of nicotine. The nicotine component of the gel formulation may be the most volatile component of the gel formulation. In some embodiments, water may be the most volatile component of the gel formulation, and the nicotine component of the gel formulation may be the second most volatile component of the gel formulation.

[0067] The aerosol generating system may comprise a heat source, an aerosol generating substrate, at least one air inlet downstream of the aerosol generating substrate, and an air flow path extending between the at least one air inlet and the mouth-side end of the article. The heat source is preferably upstream of the aerosol generating substrate. The heat source may be integral with the aerosol generating device, or the consumable aerosol generating article may be releasably received within the aerosol generating device.

[0068] The heat source may be a combustible heat source, a chemical heat source, an electrical heat source, a heat sink, or any combination thereof. The heat source may be an electrical heat source, preferably formed in the form of a blade that can be inserted into the aerosol generating substrate. Alternatively, the heat source may be configured to surround the aerosol generating substrate and may thus be in the form of a hollow cylinder or any other suitable form of this kind. Alternatively, the heat source is a combustible heat source. As used herein, a combustible heat source is a heat source that generates heat by burning itself during use, which is different from a cigarette, cigar, or cigarillo and does not involve combustion of the aerosol generating substrate. The combustible heat source may comprise carbon and an ignition aid (e.g., a metal peroxide, superoxide, or nitrate), and the metal is an alkali metal or an alkaline earth metal.

[0069] The aerosol generating substrate may include an induction heater or susceptor, or a plurality of induction heaters or susceptors. The induction heater or susceptor is heated in the presence of an alternating electromagnetic field or a fluctuating electromagnetic field. When the heating is by induction heating, the fluctuating electromagnetic field is transmitted through the aerosol generating article to the induction heater or susceptor, whereby the susceptor or induction heater converts the fluctuating field into thermal energy and thus heats the aerosol generating substrate.

[0070] The induction heater or susceptor may be formed from any material that can be induction heated to a temperature sufficient to generate aerosol from the aerosol generating substrate. The induction heater or susceptor may include metal or carbon. Preferred induction heaters or susceptors may include ferromagnetic materials (such as ferrite iron), or ferromagnetic steel or stainless steel. The induction heater or susceptor may include aluminum. The induction heater or susceptor may be formed from 400 series stainless steel, such as grade 410, or grade 420, or grade 430 stainless 20 steel. Different materials dissipate different amounts of energy when positioned within an electromagnetic field having similar values of frequency and magnetic field strength. The induction heater or susceptor is preferably heated to a temperature in excess of 250 degrees Celsius. However, the induction heater or susceptor is preferably heated to less than 350 degrees Celsius in order to prevent combustion of the material in contact with the susceptor.

[0071] The induction heater or susceptor may be positioned in proximity to the wrapper of the aerosol generating substrate since the wrappers described herein advantageously resist combustion.

[0072] The term "mouthpiece" is used herein to denote the part of an aerosol-generating article that is designed to come into contact with the consumer's mouth. The mouthpiece can be the part of the aerosol-generating article that may include a filter, or in some cases, the mouthpiece can be defined by the extent of a tipping wrapper. In other cases, the mouthpiece can be defined as a portion of the aerosol-generating article that extends about 40 mm from the mouth-side end of the aerosol-generating article, or extends about 30 mm from the mouth-side end of the aerosol-generating article.

[0073] The terms "upstream" and "downstream" refer to the relative position of elements of the aerosol-generating article described in relation to the direction of the aerosol drawn from the aerosol-generating substrate and passing through the mouthpiece.

[0074] The terms "wrapper" or "paper wrapper" are interchangeable and refer to one or more layers of wrapping material that enclose the aerosol-generating substrate to contain the aerosol-generating substrate or to maintain the shape of the aerosol-generating article and is formed of paper. The wrapper reduces the ability of the aerosol-generating article to become wet on its outer surface. The wrapper preferably contacts the aerosol-generating substrate.

[0075] The term "hydrophobic" refers to a surface that exhibits water-repellent properties. One useful way to determine this is to measure the water contact angle. The "water contact angle" is the angle conventionally measured through a liquid, where the liquid / vapor interface meets the solid surface. This quantifies the wetting of the solid surface by the liquid via Young's equation. The hydrophobicity or water contact angle may be determined by utilizing the TAPPI T558 test method, and the results are reported as the interfacial contact angle in "degrees" and can range from approximately 0 to approximately 180 degrees.

[0076] The present disclosure relates to a composite material wrapper including a first paper layer and a second paper layer used for aerosol generating articles, the composite material wrapper having reduced expansion, low penetration or wicking of grease, and may also be used with an aerosol generating substrate. According to the present disclosure, an aerosol generating article including an aerosol generating substrate containing nicotine is provided, and the first paper layer is disposed around the aerosol generating substrate. The first paper layer has a first thickness / grammage value. The second paper layer is disposed around the first paper layer. The second paper layer has a second thickness / grammage value. The first thickness / grammage value is smaller than the second thickness / grammage value. The first paper layer preferably has a thickness / grammage value of about 1.2 micrometers / gsm or less. The first paper layer preferably has a thickness / grammage value of about 1 micrometer / gsm or less.

[0077] The first paper layer may have a thickness / grammage within the range of about 0.8 micrometers / gsm to about 1.2 micrometers / gsm. The first paper layer may have a thickness / grammage within the range of about 1.0 micrometers / gsm to about 1.2 micrometers / gsm. The first paper layer may have a thickness / grammage of about 1.0 micrometers / gsm. The first paper layer may have a thickness / grammage of about 0.9 micrometers / gsm. The first paper layer may have a thickness / grammage of about 1.1 micrometers / gsm. The first paper layer may have a thickness / grammage of about 1.2 micrometers / gsm.

[0078] The combined thickness of the first paper layer and the second paper layer preferably has a thickness of less than about 80 micrometers or less than about 75 micrometers.

[0079] The first paper layer may have a thickness in the range of about 10 micrometers to about 50 micrometers. The first paper layer may have a thickness in the range of about 20 micrometers to about 50 micrometers. The first paper layer may have a thickness in the range of about 30 micrometers to about 50 micrometers. The first paper layer may have a thickness in the range of about 35 micrometers to about 50 micrometers. The first paper layer may have a thickness in the range of about 35 micrometers to about 40 micrometers.

[0080] The second paper layer may surround and contact the first paper layer. The second paper layer may have a thickness in the range of about 20 micrometers to about 50 micrometers. The second paper layer may have a thickness in the range of about 30 micrometers to about 50 micrometers. The second paper layer may have a thickness in the range of about 40 micrometers to about 50 micrometers.

[0081] The first paper layer may have a basis weight in the range of about 25 gsm to about 45 gsm. The first paper layer may have a basis weight in the range of about 30 gsm to about 45 gsm. The first paper layer may have a basis weight in the range of about 35 gsm to about 45 gsm. The first paper layer may have a basis weight in the range of about 35 gsm to about 40 gsm.

[0082] In one embodiment, the first paper layer has a thickness of about 37 micrometers and a basis weight of about 35 gsm. This first paper layer has a thickness / basis weight value of about 1.06. The second paper layer has a thickness of about 40 - 45 micrometers.

[0083] In one embodiment, the first paper layer has a basis weight in the range of about 35 gsm to about 40 gsm and a thickness in the range of about 35 micrometers to about 45 micrometers. This first paper layer has a water contact angle in the range of about 35 degrees to about 50 degrees. The second paper layer has a thickness of about 40 - 45 micrometers.

[0084] In one embodiment, the first paper layer has a basis weight of from about 35 gsm to about 40 gsm and a thickness of from about 35 micrometers to about 45 micrometers. This first paper layer has a water contact angle of from about 35 degrees to about 50 degrees. The second paper layer has a thickness of from about 40 to 45 micrometers. The second paper layer contains PVOH (polyvinyl alcohol) or silicon.

[0085] In one embodiment, the first paper layer has a basis weight of from about 35 gsm to about 40 gsm and a thickness of from about 35 micrometers to about 45 micrometers. This first paper layer has a water contact angle of from about 35 degrees to about 50 degrees. The second paper layer has a thickness of from about 40 to 45 micrometers. The second paper layer has a water contact angle value smaller than that of the first paper layer.

[0086] In combination with certain embodiments, the first paper layer contains PVOH (polyvinyl alcohol) or silicon. In one embodiment, the first paper layer contains PVOH (polyvinyl alcohol). The PVOH may be applied to the first paper layer as a surface coating. The PVOH may be disposed on the outer surface of the first paper layer of the aerosol generating article. The PVOH may be disposed on the outer surface of the first paper layer of the aerosol generating article and form a layer. The PVOH may be disposed on the inner surface of the first paper layer of the aerosol generating article. The PVOH may be disposed on the inner surface of the first paper layer of the aerosol generating article and form a layer. The PVOH may be disposed on both the inner and outer surfaces of the first paper layer of the aerosol generating article. The PVOH may be disposed on both the inner and outer surfaces of the first paper layer of the aerosol generating article and form a layer.

[0087] The first paper layer may include a surface treatment containing PVOH or silicon. The first paper layer may include a surface treatment containing PVOH. The first paper layer may include a surface treatment containing silicon. This surface treatment may be applied to the outer surface of the first paper layer. This surface treatment may be applied to the inner surface of the first paper layer. This surface treatment may be applied to both the outer surface and the inner surface of the first paper layer. The addition of PVOH or silicon may improve the grease barrier properties of the first paper layer.

[0088] The second paper layer is preferably surrounded by the first paper layer. The first paper layer may contain PVOH, and the second wrapper may not contain PVOH. The first wrapper may contain silicon, and the second paper layer may not contain silicon. In some embodiments, both the first wrapper and the second wrapper contain PVOH or silicon.

[0089] The second wrapper preferably contains PVOH or silicon.

[0090] In some embodiments, the wrapper includes three or more paper layers.

[0091] The aerosol generating substrate may contain a gel composition. The gel composition may contain a large amount of aerosol formers such as glycerin. The gel composition may contain nicotine, at least about 50 wt% glycerin or at least 70 wt% glycerin, at least about 0.2 wt% hydrogen bond cross-linking gelling agent, at least about 0.2 wt% ionic cross-linking gelling agent, and at least about 0.2 wt% thickening agent. The gel composition may contain xanthan gum.

[0092] The aerosol generating substrate may contain a homogenized tobacco material. The homogenized tobacco material of tobacco may contain a tobacco material, about 1% to about 5% binder, and about 5% to about 30% aerosol former on a dry weight basis.

[0093] The aerosol generating substrate may include a metal induction heating element. The metal induction heating element may include a plurality of metal induction heating elements. The metal induction heating element may include a metal induction heating ring element.

[0094] The wrapper described herein is intended to potentially reduce and prevent the formation of stains on the aerosol generating article visible to the consumer. It has been observed that stains may appear on the aerosol generating article during storage in a high humidity environment or during consumption. Stains may be caused by water or an aerosol forming substance containing any suspended or dissolved colored substance being absorbed into the web of cellulosic fibers constituting the wrapper. Without being bound by any theory, water or the aerosol forming substance interacts with the cellulosic fibers of the paper, changing the fiber structure, resulting in local changes in optical properties such as brightness, color, opacity, etc., and mechanical properties such as the tensile strength and permeability of the wrapper.

[0095] The wrapper described herein is intended to potentially reduce and prevent the expansion of the aerosol generating article. Reducing or preventing the expansion of the aerosol generating article improves the usefulness of the aerosol generating article such that it can be reliably inserted into and removed from the heating device without damaging the aerosol generating article.

[0096] The wrapper is the portion of the aerosol generating article disposed around the aerosol generating substrate to assist in maintaining the cylindrical shape of the aerosol generating article. The wrapper may encompass the aerosol generating substrate over at least about 50% of the length of the plug of the aerosol generating substrate. Preferably, the wrapper encompasses the aerosol generating substrate over at least about 90% of the length of the plug of the aerosol generating substrate. More preferably, the wrapper encompasses the aerosol generating substrate over at least about 100% of the length of the plug of the aerosol generating substrate.

[0097] This wrapper may exhibit a certain range of permeability, which includes no permeability. The permeability of cigarette paper is determined using the international standard test method ISO 2965:2009, and the results are expressed in cubic centimeters per minute per square centimeter and are referred to as "Coressta units". The permeability of the wrapper described herein may be in the range of about 1 to about 10 Coressta units, about 5 to about 20 Coressta units, or about 1 to about 5 Coressta units.

[0098] The wrapper may be formed from any cellulosic material such as paper, wood, fabric, natural fibers, and man-made fibers. The wrapper preferably does not contain a filler such as calcium carbonate. The wrapper is preferably formed from at least 90% by weight of cellulosic material. The wrapper is preferably formed from at least 95% by weight of cellulosic material.

[0099] The paper layer (the "paper layer" refers to the first paper layer, or the second paper layer, or both) may be formed from any cellulosic material such as paper, wood, fabric, natural fibers, man-made fibers, etc. The paper layer preferably does not contain a filler such as calcium carbonate. The paper layer is preferably formed from at least 90% by weight of cellulosic material. The paper layer is preferably formed from at least 95% by weight of cellulosic material.

[0100] The surface of the paper layer may have a water contact angle of at least about 30 degrees, at least about 35 degrees, at least about 40 degrees, or at least about 45 degrees. The hydrophobicity or water contact angle is determined using the TAPPI T558 test, and the results are reported as the interfacial contact angle in "degrees" and can range from approximately 0 degrees to approximately 180 degrees.

[0101] The term "MD" refers to the machine direction of the wrapper. The machine direction is the direction in which the paper stock flows into and through the papermaking machine. The machine direction is the circumferential direction of the paper roll wound from the paper machine. The machine direction may also be referred to as the grain direction.

[0102] The term "CD" refers to the transverse direction of the wrapper. The transverse direction of the wrapper is within the plane of the wrapper. The transverse direction of the wrapper is orthogonal to the machine direction of the wrapper.

[0103] The paper layer may have a CD / MD elongation at break ratio of about 2.5 or less. The paper layer may have a CD / MD elongation at break ratio of about 2.2 or less, or about 2 or less. The paper layer may have a CD / MD elongation at break ratio within the range of about 1.8 to 2.2.

[0104] The paper layer may have a negative result (no visible stain) for at least one kit oil sample of the method Tappi 559cm-02 classical method 2002. The paper layer may have a negative result for at least 5 kit oil samples, or all 10 kit oil samples of the method Tappi 559cm-02 classical method 2002.

[0105] The wrapper may include two paper layers. The first paper layer contacts the aerosol-forming substrate, and the second paper layer overlaps the first paper layer. The first paper layer may include PVOH (polyvinyl alcohol) or silicon, or may include a surface treatment containing PVOH or silicon. The second paper layer may include PVOH (polyvinyl alcohol) or silicon, or may include a surface treatment containing PVOH or silicon. Both the first and second paper layers may include PVOH (polyvinyl alcohol) or silicon, or may include a surface treatment containing PVOH or silicon. Only the first paper layer may include PVOH (polyvinyl alcohol) or silicon, or may include a surface treatment containing PVOH or silicon. Only the second paper layer may include PVOH (polyvinyl alcohol) or silicon, or may include a surface treatment containing PVOH or silicon.

[0106] An aerosol-generating article includes an aerosol-generating substrate, which may include a tobacco charge surrounded by a wrapper as described herein. The aerosol-generating substrate may include any suitable type(s) of tobacco material or tobacco substitute in any suitable form. The aerosol-generating substrate may include full cured tobacco, burley tobacco, maryland tobacco, oriental leaf tobacco, specialty tobacco, homogenized or reconstituted tobacco, or any combination thereof. The aerosol-generating substrate may be provided in the form of tobacco cut filler, tobacco leaf lamina, processed tobacco materials such as volume expanded or puffed tobacco, processed tobacco stems such as cut rolled or cut puffed stems, homogenized tobacco, reconstituted tobacco, cast leaf tobacco, or blends thereof, and the like. The term "tobacco cut filler" is used herein to denote a tobacco material mainly formed from the lamina portion of a tobacco leaf. The term "tobacco cut filler" is used herein to denote both a single species of the genus Nicotiana and two or more species of the genus Nicotiana forming a tobacco cut filler blend.

[0107] As used herein, the term "homogenized tobacco" means a material formed by aggregating particulate tobacco. Homogenized tobacco may include reconstituted tobacco or cast leaf tobacco, or a mixture of both. The term "reconstituted tobacco" refers to a paper-like material that can be made from tobacco by-products such as tobacco fines, tobacco dust, tobacco stems, or mixtures of the foregoing. Reconstituted tobacco can be made by extracting soluble chemicals from the tobacco by-products, processing the remaining tobacco fibers into a sheet, and then reapplying the extracted material in concentrated form onto the sheet. The term "cast leaf tobacco" is used herein to refer to a product resulting from a process well known in the art, which is based on casting a slurry containing ground tobacco particles and a binder (e.g., guar) onto a support surface (such as a belt conveyor), drying the slurry, and removing the dried sheet from the support surface. Exemplary methods for manufacturing these types of aerosol-generating substrates are described in U.S. Pat. Nos. 5,724,998, 5,584,306, 4,341,228, 5,584,306, and 6,216,706. Homogenized tobacco may be crimped, wrapped, folded, or otherwise compressed into a sheet before being rolled to form a rod. For example, the sheet of homogenized tobacco material used in the present invention may be crimped using a crimping unit of the type described in Swiss Patent No. 691156, which comprises a pair of rotatable crimping rollers. However, it goes without saying that the sheet of homogenized tobacco material used in the present invention may be textured using other suitable machinery and processes that deform or perforate the sheet of homogenized tobacco material.

[0108] The aerosol generation substrates used in aerosol generating articles generally contain a higher amount of aerosol former(s) than combustion smoking articles such as cigarettes. Humectants can also be referred to as "aerosol formers". Aerosol formers are used to describe any suitable well-known compound or mixture of compounds that facilitates the formation of aerosol during use and is substantially resistant to thermal decomposition at the operating temperature of the aerosol generation substrate. Suitable aerosol formers are well-known in the art and include polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3-butanediol, glycerin, etc.), esters of polyhydric alcohols (such as glycerin monoacetate, diacetate, triacetate, etc.), and aliphatic esters of monocarboxylic acids, dicarboxylic acids or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.), but are not limited thereto. Preferred aerosol formers are polyhydric alcohols or mixtures thereof (such as propylene glycol, triethylene glycol, 1,3-butanediol, etc.), most preferably glycerin or glycerin. The aerosol generation substrate may contain a single aerosol former. Alternatively, the aerosol generation substrate may contain a combination of two or more aerosol formers.

[0109] The aerosol generation substrate may have a high amount of aerosol former. As used herein, a high amount of aerosol former means an aerosol former content of more than about 10% by weight, or preferably more than about 15% by weight, or more preferably more than about 20% by weight. The aerosol generation substrate can also have an aerosol former content of about 10% to about 30% by weight, about 15% to about 30% by weight, or about 20% to about 30% by weight. The aerosol generation substrate can also have a glycerin content of about 10% to about 30% by weight, about 15% to about 30% by weight, or about 20% to about 30% by weight.

[0110] The aerosol generating substrate may contain at least about 1 wt%, or at least about 2 wt%, or at least about 5 wt%, or at least about 7 wt%, or at least about 10 wt%, or at least about 12 wt%, or at least about 15 wt%, or at least about 18 wt% of an aerosol former. The aerosol generating substrate may contain an aerosol former in the range of about 1 to about 20 wt%, or about 5 to about 20 wt%, or about 10 to about 20 wt%.

[0111] The aerosol generating substrate may contain at least about 1 wt%, or at least about 2 wt%, or at least about 5 wt%, or at least about 7 wt%, or at least about 10 wt%, or at least about 12 wt%, or at least about 15 wt%, or at least about 18 wt% of glycerin. The aerosol generating substrate may contain glycerin in the range of about 1 to about 20 wt%, or about 5 to about 20 wt%, or about 10 to about 20 wt%.

[0112] The aerosol generating substrate in gel form may have a large amount of aerosol former, preferably glycerin. The gel composition may contain a gelling agent forming a solid medium, an aerosol former such as glycerin dispersed in the solid medium, and nicotine dispersed in the glycerin. The composition forms a stable gel phase. The gel composition may contain at least two gelling agents forming a solid medium, glycerin dispersed in the solid medium, and nicotine dispersed in the glycerin. The composition forms a stable gel phase. The gel composition may contain a thickening agent, a gelling agent forming a solid medium, glycerin dispersed in the solid medium, and nicotine dispersed in the glycerin. The composition forms a stable gel phase. The gel composition may contain nicotine, an aerosol former, a thickening agent, a hydrogen bond cross-linked gelling agent, an ionic cross-linked gelling agent. The gel composition may further contain a divalent cation.

[0113] The gel composition may contain a large amount of aerosol formers such as glycerin. The gel composition may contain a mixture of water and glycerin, where glycerin forms the majority (by weight) of the gel composition. Glycerin may form at least about 50% by weight of the gel composition. Glycerin may form at least about 60% by weight, or about 65% by weight, or about 70% by weight of the gel composition. Glycerin may form from about 70% to about 80% by weight of the gel composition. Glycerin may form from about 70% to about 75% by weight of the gel composition.

[0114] The wrapper described herein is disposed around the aerosol generating substrate. The wrapper can reduce the absorption of aerosol former compounds and water into the wrapper when air is drawn through the heated aerosol generating article.

[0115] Preferably, the aerosol generating article may generally be cylindrical. This allows for a smooth flow of the aerosol. The aerosol generating article may have an outer diameter of, for example, 4 millimeters to 15 millimeters, 5 millimeters to 10 millimeters, or 6 millimeters to 8 millimeters. The aerosol generating article may have a length of, for example, 10 millimeters to 60 millimeters, 15 millimeters to 50 millimeters, or 20 millimeters to 45 millimeters.

[0116] The draw resistance (RTD) of an aerosol-generating article varies, inter alia, according to the length and dimensions of the passageway, the size of the apertures, the dimensions of the most constricted cross-sectional area of the internal passageway, and the materials used. The RTD of an aerosol-generating article may be from 50 millimetres of water column (mmH2O) to 140 millimetres of water column (mmH2O), from 60 millimetres of water column (mmH2O) to 120 millimetres of water column (mmH2O), or from 80 millimetres of water column (mmH2O) to 100 millimetres of water column (mmH2O). The RTD of an article refers to the difference in static pressure between one or more apertures of the article and the mouth end when crossing the inner longitudinal axis passageway under steady state conditions where the volumetric flow rate is 17.5 millilitres per second at the mouth end. The RTD of a specimen can be measured using the method described in ISO standard 6565:2002.

[0117] All scientific and technical terms used in this specification have the meanings commonly used in the art, unless otherwise specified. The definitions provided in this specification are provided to facilitate the understanding of specific terms frequently used herein.

[0118] As used in this specification and the appended claims, the singular forms "a", "an", and "the" include embodiments having a plural referent, unless the context clearly dictates otherwise.

[0119] As used in this specification and the appended claims, the term "or" is generally used in the sense of "and / or", unless the context clearly dictates otherwise.

[0120] As used herein, the terms "have", "having", "include", "including", "comprise", "comprising", or the like are used in an open-ended sense and generally mean "including but not limited to". Of course, "consisting essentially of", "consisting of", and the like are subsumed under "comprising" and the like.

[0121] The terms "preferred" and "preferably" refer to embodiments of the present invention that may provide certain advantages under certain circumstances. However, under the same or other circumstances, other embodiments may also be preferred. Moreover, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the present disclosure, including the claims.

Brief Description of the Drawings

[0122]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0123] The aerosol-generating articles illustrated in FIGS. 1-4 exemplify one or more embodiments of the above-described aerosol-generating articles or components of aerosol-generating articles. The schematic diagrams are not necessarily to scale and are presented for illustrative purposes and are not limiting. The drawings illustrate one or more aspects described in the present disclosure. However, other aspects not illustrated in the drawings are also within the scope and spirit of the present disclosure.

[0124] The aerosol-generating article 10 of FIG. 1 exemplifies an aerosol-generating substrate 12 including a tobacco plug, a hollow cellulose acetate tube 14, a polylactic acid filter segment 16, and a mouthpiece segment 18 formed from a cellulose acetate material. These four elements are individually wrapped with a paper layer. In particular, the aerosol-generating substrate 12 is wrapped with a first paper layer 50 as described herein. These four elements are arranged in alignment in the longitudinal direction with ends in contact.

[0125] The aerosol-generating substrate 12, the hollow cellulose acetate tube 14, and the polylactic acid filter segment 16 are joined together and surrounded by a second paper layer 20 to form an intermediate article. The mouthpiece segment 18 is joined to the intermediate article with tipping paper 25 to form the aerosol-generating article 10. The first paper layer 50 and the second paper layer 20 may cooperate to form a wrapper as described herein.

[0126] The aerosol-generating article 10 has a mouth-side end 22 and an upstream distal end 24 located at the end of the article opposite the mouth-side end 22. The aerosol-generating article 10 shown in FIG. 1 is particularly suitable for use in an electrically operated aerosol-generating device that includes a heater for heating the aerosol-generating substrate 12.

[0127] The aerosol generating article 100 of FIG. 2 comprises four coaxially aligned elements: an end plug 600 with a high draw resistance (RTD) at the distal end 103, a first paper layer 500 surrounding the aerosol generating substrate 124, a fluid guide 400, and a mouthpiece 170 at the proximal end 101. These four elements are sequentially arranged and surrounded by a second paper layer 110 to form the aerosol generating article 100. The aerosol generating article 100 has a proximal or mouth-side end 101 and a distal end 103 located at the end of the aerosol generating article 100 opposite the proximal end 101. The first paper layer 500 and the second paper layer 110 may cooperate to form a wrapper as described herein.

[0128] The aerosol generating article 100 of FIG. 3 illustrates a cutaway view of an example of an aerosol generating article 100 that is suitable for heating using not only inductive heating but also a blade-like heating element.

[0129] The aerosol-generating article 100 comprises, in proximal to distal order, a mouthpiece 170 at the proximal end 101, a fluid guide 400, a cavity 700, a first paper layer 500 surrounding the aerosol-generating substrate 124, and a plug 600. In this embodiment, the aerosol-generating substrate 124 comprises a gel and a susceptor (not shown). The susceptor in this embodiment is a single aluminum strip located centrally along the longitudinal axis of the aerosol-generating substrate 124. When the distal end 103 of the aerosol-generating article 100 is inserted into the aerosol-generating device 200 (see FIG. 6), the portion of the aerosol-generating article 100 is thereby positioned close to the induction heating element 230 (see FIG. 5) of the aerosol-generating device 200. The electromagnetic radiation generated by the induction heating element 230 is absorbed by the susceptor and assists in heating the aerosol-generating substrate 124 within the first paper layer 500, which in turn assists in the release of material from the aerosol-generating substrate 124 (e.g., the entrainment of nicotine into the passing aerosol when a negative pressure is applied to the proximal end 101 of the aerosol-generating article 100). A fluid, such as air, enters the outer longitudinal passage 831 through an opening (not shown), moves to the cavity 700, then to the aerosol-generating substrate 124, where the fluid mixes with the aerosol-generating substrate 124 and entrains nicotine, then returns to the cavity and then exits at the proximal end 101 after passing through the inner longitudinal passage (not shown) of the fluid guide 400.

[0130] In this embodiment, the first paper layer 500 surrounds the aerosol-generating substrate 124, and the first paper layer 500 is surrounded by a second paper layer 110. The first paper layer 500 and the second paper layer 110 form a wrapper as described herein. The aerosol-generating substrate 124 may include a gel composition.

[0131] This aerosol-generating article 100, illustrated in FIGS. 2 and 3, may be used with an aerosol-generating device 200 as illustrated in FIGS. 5 and 6.

[0132] The aerosol-generating article 10 of FIG. 4 exemplifies an aerosol-generating substrate 12, a hollow cellulose acetate tube 14, a hollow tubular segment 16, and a mouthpiece segment 18. The aerosol-generating substrate 12 is wrapped with a first paper layer 50 as described herein. These four elements are arranged in end-to-end alignment in the longitudinal direction and are surrounded by a second paper layer 20 to form the aerosol-generating article 10. The first paper layer 50 and the second paper layer 20 may cooperate to form a wrapper as described herein.

[0133] The aerosol-generating article 10 has a mouth-side end 22 and an upstream distal end 24 located at the end of the article opposite the mouth-side end 22. The aerosol-generating article 10 shown in FIG. 4 is particularly suitable for use in an electrically operated aerosol-generating device that includes a heater for heating the aerosol-generating substrate 12.

[0134] The aerosol-generating substrate 12 has a length of about 12 millimeters and a diameter of about 7 millimeters. The aerosol-generating substrate 12 has a cylindrical shape and a substantially circular cross-section. The aerosol-generating substrate 12 comprises an assembly of sheets of homogenized tobacco material. The sheets of homogenized tobacco material contain 10 weight percent glycerin on a dry basis. The hollow cellulose acetate tube 14 has a length of about 8 millimeters and a thickness of 1 millimeter. The mouthpiece segment 18 comprises a plug of 8-denier cellulose acetate tow per filament and has a length of about 7 millimeters.

[0135] The hollow tubular segment 14 is provided as a cylindrical tube having a length of about 18 millimeters, and the wall thickness of the tube is about 100 micrometers. The aerosol generating article 10 includes a ventilation zone 26 provided about 5 millimeters upstream from the upstream end of the mouthpiece segment 18. Accordingly, the ventilation zone 26 is located about 12 millimeters from the downstream end of the aerosol generating article, and about 13 millimeters from the upstream end of the hollow tubular segment. Accordingly, the ventilation zone 26 is located about 21 millimeters from the downstream end of the aerosol generating substrate 12.

[0136] Figures 5-6 illustrate an embodiment of an aerosol generating article 100 and an aerosol generating device 200. The aerosol generating article 100 has a proximal or mouth-side end 101 and a distal end 103. In Figure 5, the distal end 103 of the aerosol generating article 100 is received within the receiving portion 220 of the aerosol generating device 200. The aerosol generating device 200 includes a housing 210 that defines a receiving portion 220 configured to receive the aerosol generating article 100. The aerosol generating device 200 also includes a heating element 230 that forms a cavity 235 configured to receive the aerosol generating article 100, preferably by interference fit. The heating element 230 may comprise an electrical resistance heating component. Additionally, the device 200 includes a power source 240 and control electronics 250 that cooperate to control the heating of the heating element 230.

[0137] The heating element 230 may heat the distal end 103 of the aerosol generating article 100. In this embodiment, the aerosol generating substrate 124 includes a gel containing nicotine. Heating the aerosol generating article 100 generates an aerosol containing nicotine in the aerosol generating substrate 124, and this aerosol can move out of the aerosol generating article 100 at the proximal end 101. The aerosol generating device 200 includes a housing 210. Figures 5-6 do not show the exact heating mechanism.

[0138] In some embodiments, the heating mechanism can be by conduction heating in which heat is transferred from the heating element 230 of the aerosol generating device 200 to the aerosol generating article 100. This can be easily done when the aerosol generating article 100 is positioned within the receiving portion 220 of the aerosol generating device 200 and the distal end 103 (preferably the end where the aerosol generating substrate 124 is located) and thus the aerosol generating article 100 is in contact with the heating element 230 of the aerosol generating device 200. In certain embodiments, the heating element comprises a heating blade that protrudes from the aerosol generating device 200 and is adapted to penetrate into the aerosol generating article 100 and make direct contact with the aerosol generating substrate 124.

[0139] In this embodiment, the heating mechanism is by induction in which the heating element emits radio magnetic radiation that is absorbed by the tubular element when the aerosol generating article 100 is positioned within the receiving portion 220 of the aerosol generating device 200.

[0140] When the aerosol generating article 100 is releasably received within the aerosol generating device 200 and on top of the heating element 230, the aerosol generating device 200 is activated to heat the aerosol generating substrate 124 to a temperature of approximately 375 degrees Celsius. When the user sucks on the mouth-side end 101 of the aerosol generating article 100, the volatile compounds released from the aerosol generating substrate 124 are drawn downstream through the aerosol generating article 100 and condensed to form an aerosol that is drawn into the user's mouth through the mouthpiece 101 of the aerosol generating article 100. The wrappers 500, 110 repel aerosol-forming substances and moisture from the aerosol, reducing soiling and weakening of the wrappers 500, 110.

[0141] The first paper layers 50, 500 have a thickness / grammage of 1.2 micrometers / gsm or less. The first paper layers 50, 500 preferably have a thickness / grammage within the range of about 1.0 micrometers / gsm to about 1.2 micrometers / gsm. The first paper layers 50, 500 may have a thickness of less than about 50 micrometers, or less than about 40 micrometers. The first paper layers 50, 500 may have a grammage within the range of about 25 gsm to about 45 gsm, or about 35 gsm to about 40 gsm.

[0142] The first paper layers 50, 500 preferably have a thickness / grammage of 1.2 micrometers / gsm or less and a water contact angle of at least about 30 degrees. The first paper layer 50, 500 may have a water contact angle of at least about 40 degrees, or at least about 45 degrees.

[0143] The first paper layers 50, 500 preferably have a thickness / grammage of 1.2 micrometers / gsm or less and a CD / MD elongation at break ratio of about 2.5 or less. The first paper layers 50, 500 may have a CD / MD elongation at break ratio of about 2.2 or less, or about 2 or less.

[0144] Preferably, the first paper layers 50, 500 have a thickness / grammage of 1.2 micrometers / gsm or less and a negative result for at least one kit oil sample of the Tappi 559cm-02 classical method 2002. The first paper layers 50, 500 may have a negative result for at least 5 kit oil samples, or all 10 kit oil samples of the Tappi 559cm-02 classical method 2002.

[0145] The wrapper includes first paper layers 50, 500 and second paper layers 20, 110. The first paper layers 50, 500 have a first thickness / grammage value, and the second paper layers 20, 110 have a second thickness / grammage value. The first thickness / grammage value is smaller than the second thickness / grammage value. The first thickness / grammage value may be less than 1.2 micrometers / gsm, and the wrapper may have a total thickness of less than about 80 micrometers.

[0146] The second paper layers 20, 110 preferably contain PVOH (polyvinyl alcohol) or silicon. The second paper layers 20, 110 may include a surface treatment containing PVOH or silicon. The addition of PVOH (polyvinyl alcohol) or silicon may improve the grease barrier properties of the wrapper.

[0147] The first paper layers 50, 500 may contain PVOH (polyvinyl alcohol) or silicon. The first paper layers 50, 500 may include a surface treatment containing PVOH or silicon. The addition of PVOH (polyvinyl alcohol) or silicon may improve the grease barrier properties of the wrapper.

[0148] The above exemplary embodiments are not limiting. Other embodiments consistent with the above exemplary embodiments will be apparent to those skilled in the art.

Claims

1. An aerosol-generating article, comprising: an aerosol-generating substrate comprising nicotine and at least about 10% of an aerosol former, based on the weight of the aerosol-generating substrate, which contains glycerin; a first paper layer disposed around the aerosol-generating substrate, the first paper layer having a first thickness / grammage value; a second paper layer disposed around the first paper layer, the second paper layer having a second thickness / grammage value, the first thickness / grammage value being smaller than the second thickness / grammage value.

2. The aerosol-generating article according to claim 1, wherein the first paper layer has a paper thickness / grammage of about 1.2 micrometers / gsm or less.

3. The aerosol-generating article according to any one of claims 1 to 2, wherein the first paper layer has a grammage in the range of about 25 gsm to about 45 gsm and a thickness in the range of about 35 micrometers to about 50 micrometers.

4. The aerosol-generating article according to any one of claims 1 to 3, wherein the total thickness of the first paper layer and the second paper layer is 80 micrometers or less.

5. The aerosol-generating article according to any one of claims 1 to 4, wherein the second paper layer contains PVA or siloxane.

6. The aerosol-generating article according to any one of claims 1 to 5, wherein the second paper layer comprises a treated surface containing PVA or siloxane.

7. The aerosol-generating article according to any one of claims 1 to 6, wherein the first paper layer contains PVA.

8. The aerosol-generating article according to any one of claims 1 to 7, wherein the first paper layer contains siloxane.

9. The aerosol-generating article according to any one of claims 1 to 8, wherein the aerosol-generating substrate contains a gel composition.

10. The aerosol-generating article according to claim 9, wherein glycerin forms at least about 50 weight percent of the gel composition.

11. The aerosol-generating article according to claim 10, wherein the gel composition contains xanthan gum.

12. The aerosol-generating article according to any one of claims 1 to 11, wherein the aerosol-generating substrate contains a homogenized tobacco material.

13. The aerosol-generating article according to claim 12, wherein the homogenized tobacco material contains, on a dry weight basis, a tobacco material, about 1 percent to about 5 percent of a binder, and about 5 percent to about 30 percent of an aerosol former.

14. The aerosol generating article according to any one of claims 1 to 13, wherein the aerosol generating substrate contains a metal induction heating element.

15. The aerosol generating article according to any one of claims 1 to 14, wherein the aerosol generating substrate contains a plurality of metal induction heating elements.

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