Aerosol-generating article with composite susceptor assembly

Abstract

There is provided an aerosol-generating article (10) for generating an inhalable aerosol upon heating, the aerosol-generating article comprising a susceptor assembly (100). The susceptor assembly comprises at least one strand (102) of susceptor material, the at least one strand (102) of susceptor material being twisted so as to be laid helically about a longitudinal axis of the susceptor assembly (100). Further, the susceptor assembly (100) comprises an aerosol-generating element comprising at least one strand (104) of porous non-tobacco material carrying an aerosol-forming composition, the aerosol-forming composition comprising at least 35% by weight of an aerosol former. At least one strand of the aerosol-generating element is twisted with at least one strand of susceptor material (102).

Description

Technical Field

[0001] The present invention relates to an aerosol generating article comprising an aerosol generating substrate and adapted to generate an inhalable aerosol upon heating. In particular, the present invention relates to an aerosol generating article comprising a susceptor element thermally coupled to the aerosol generating substrate and adapted to be inductively heated to supply heat to the aerosol generating substrate. Aspects of the present disclosure also relate to an aerosol generating system comprising a heating device and an aerosol generating article of the above type. Background Art

[0002] Aerosol generating articles in which an aerosol generating substrate such as a tobacco-containing substrate is heated rather than burned are known in the art. Typically, in such heated smoking articles, an aerosol is generated by transferring heat from a heat source to a physically separated aerosol generating substrate or material, which may be positioned in contact with the heat source, inside, around or downstream of the heat source. During the use of the aerosol generating article, volatile compounds are released from the aerosol generating substrate by heat transfer from the heat source and are entrained in the air drawn by the aerosol generating article. When the released compound cools, the compound condenses to form an aerosol.

[0003] Many prior art documents disclose aerosol generating devices for consuming aerosol generating articles. Such devices include, for example, electrically heated aerosol generating devices, wherein an aerosol is generated by transferring heat from one or more electrical heater elements of the aerosol generating device to an aerosol generating substrate of the heated aerosol generating article. For example, electrically heated aerosol generating devices comprising internal heater blades adapted to be inserted into the aerosol generating substrate have been proposed. As an alternative, an inductively heatable aerosol generating article comprising an aerosol generating substrate and a susceptor arranged within the aerosol generating substrate has been proposed by WO 2015 / 176898.

[0004] Aerosol generation articles wherein the substrate containing tobacco is heated rather than burned present many challenges that conventional smoking articles have not encountered.First, compared with the temperature reached by the combustion front in conventional cigarettes, the substrate containing tobacco is usually heated to a significantly lower temperature.This may affect the nicotine release of the substrate containing tobacco and deliver nicotine to the consumer.Meanwhile, if the heating temperature increases to attempt to strengthen nicotine delivery, the generated aerosol usually needs to cool to a greater extent and more rapidly before it arrives at the consumer.

[0005] Secondly, it usually takes some time to heat the tobacco-containing aerosol-generating substrate to even such a temperature as is required for aerosol formation, and therefore there may be a delay in the delivery of the aerosol to the consumer. This phenomenon whereby the aerosol reaching the user when the user initially draws on the article may be relatively low in flavor or nicotine content, or both, is commonly referred to as the "cold draw" effect or the "empty draw" effect.

[0006] One such delay may be detected, for example, in aerosol-generating rods and articles in which the aerosol-generating substrate comprises homogenized tobacco material, because the aerosol-forming agent and nicotine may not be readily available for release. In particular, this may occur in situations in which cast leaf homogenized tobacco material prepared from a slurry containing an aerosol-forming agent is used, as opposed to situations in which the aerosol-forming agent is applied (e.g., sprayed) onto a formed sheet.

[0007] However, it would be desirable to provide a new and improved aerosol-generating rod or article adapted to address at least one of the challenges encountered with aerosol-generating articles in which a tobacco-containing substrate is heated rather than combusted, and which are not particularly associated with conventional smoking articles in general. Summary of the invention

[0008] The present disclosure relates to an aerosol-generating article for generating an inhalable aerosol upon heating.

[0009] An aerosol-generating article may comprise a susceptor assembly.

[0010] The susceptor assembly may include at least one strand of susceptor material.

[0011] At least one strand of susceptor material may be twisted so as to be laid helically about the longitudinal axis of the susceptor assembly.

[0012] The susceptor assembly may include an aerosol generating element.

[0013] The aerosol-generating element may comprise at least one strand of porous (eg fibrous) non-tobacco material carrying an aerosol-forming composition.

[0014] The aerosol-forming composition may comprise at least 35 wt% of an aerosol former (eg glycerol).

[0015] At least one strand of the aerosol generating element may be twisted with at least one strand of susceptor material.

[0016] According to the present invention, a kind of aerosol generating article for generating an inhalable aerosol when heating is provided, and this aerosol generating article comprises a susceptor assembly.Susceptor assembly comprises at least one susceptor material strand, and this at least one susceptor material strand is twisted, so that spirally lay around the longitudinal axis of susceptor assembly.In addition, susceptor assembly comprises at least one aerosol generating element, and described at least one aerosol generating element comprises at least one porous non-tobacco material strand of carrying aerosol forming composition, and described aerosol forming composition comprises at least 35 weight % aerosol forming agent.At least one strand of aerosol generating element is twisted with at least one susceptor material strand.

[0017] In contrast to prior aerosol-generating articles, aerosol-generating articles according to the present invention comprise a susceptor assembly wherein a composition comprising a plurality of aerosol-forming agents is held in intimate contact with the inductively heatable material of at least one strand of susceptor material.

[0018] This is achieved by means of a twisted arrangement of at least one strand of susceptor material and a strand of porous non-tobacco material carrying the aerosol-forming composition of the aerosol-generating element.

[0019] From a functional point of view, in an aerosol-generating article according to the present invention, a porous non-tobacco material strand carrying an aerosol-forming composition may be regarded as an aerosol-forming strand. For the sake of brevity, in the following description, a porous non-tobacco material strand carrying an aerosol-forming composition that forms part of an aerosol-generating element will generally be referred to as an "aerosol-forming strand" or "aerosol-generating strand".

[0020] Because the at least one porous non-tobacco material strand is sandwiched between or surrounded by adjacent spirals or coils formed by the at least one susceptor material strand, the structure of the susceptor assembly of the aerosol-generating article according to the invention ensures that a significant portion of the aerosol-forming agent is always in close proximity to the heat source. Thus, during use, the inductively generated heat can be quickly transferred from the heated susceptor material strand to the at least one porous non-tobacco material strand and the aerosol-forming composition, for example by conduction.

[0021] Therefore, the rapid heating of the porous non-tobacco material strand can be achieved at the first moment after the induction heating has begun. The volatilization of the aerosol forming agent carried by at least one porous non-tobacco material strand can advantageously help prevent the occurrence of the "cold suction" effect and achieve a generally more consistent and better controlled aerosol delivery to the consumer during use.

[0022] As will become apparent from the following description, preferred embodiments of aerosol-generating articles according to the present invention may benefit in particular from certain mutual arrangements of one or more strands of receptor material and one or more strands of an aerosol generating element (i.e., one or more aerosol-forming strands), and from the use of certain formulations of the aerosol-forming composition, which may render the aerosol-forming agent particularly suitable for faster release than volatile substances contained in a naturally occurring aerosol-generating matrix.

[0023] By adjusting the number of susceptor material strands, the number of aerosol-forming strands, or certain parameters of the helical arrangement of the strands about the longitudinal axis of the susceptor assembly, the amount of aerosol-forming agent volatilized and delivered to the consumer, particularly during the first moments of use after inductive heating has begun, can advantageously be fine-tuned and controlled. For example, by varying the number of susceptor material strands and the helix angle of the strands of susceptor material laid out about the longitudinal axis of the susceptor, it is possible to vary the amount of exposed surface area of ​​the aerosol-forming strands and the amount of surface area of ​​at least one aerosol-forming strand that is in direct contact with one or more susceptor material strands.

[0024] In other preferred embodiments described in more detail below, the distance between adjacent strands of susceptor material and their mutual spatial arrangement can be fine-tuned and controlled. This can be achieved, for example, by providing one or more spacer elements as additional components of the susceptor assembly. Thus, the size of the gap formed within the structure of the susceptor assembly can be adjusted so that the gap is suitable for accommodating a limited amount of aerosol-generating substrate. This can advantageously provide a further degree of control over the total amount and spatial distribution of the substrate capable of releasing volatile substances upon heating, which is disposed in close proximity to the susceptor material.

[0025] As briefly described above, the present invention provides an aerosol-generating article for generating an inhalable aerosol upon heating.

[0026] The term "aerosol-generating article" is used herein to refer to an article in which an aerosol-generating substrate is heated to generate and deliver an inhalable aerosol to a consumer. As used herein, the term "aerosol-generating substrate" refers to a substrate capable of releasing volatile compounds upon heating to generate an aerosol.

[0027] In an aerosol-generating article according to the invention, the aerosol-forming composition carried by the porous non-tobacco material strand forming part of the susceptor assembly acts as one such aerosol-generating substrate. In some embodiments, as will be described in more detail below, the aerosol-generating article may include additional aerosol-generating substrates in addition to the aerosol-forming composition.

[0028] A conventional cigarette will ignite when a user applies a flame to one end of the cigarette and draws air through the other end. The localized heat provided by the flame and the oxygen in the air drawn through the cigarette causes the end of the cigarette to ignite, and the resulting combustion generates inhalable smoke. In contrast, in a heated aerosol-generating article, an aerosol is generated by heating a flavor-generating substrate (e.g., tobacco) without burning the flavor-generating substrate. Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles, and aerosol-generating articles in which an aerosol is generated by heat transfer from a combustible fuel element or heat source to a physically separate aerosol-forming material.

[0029] The aerosol generating article according to the present invention is particularly suitable for use in an aerosol generating system comprising an aerosol generating device having an inductor for generating an alternating or fluctuating electromagnetic field. The aerosol generating article is coupled to the aerosol generating device so that the fluctuating electromagnetic field generated by the inductor induces a current in the susceptor assembly, thereby causing the susceptor material strand to heat up. The electrically operated aerosol generating device may be capable of generating a fluctuating electromagnetic field having a magnetic field strength (H field strength) between 1 and 5 kiloamperes per meter (kA / m), preferably between 2 and 3 kA / m, for example about 2.5 kA / m. Preferably, the electrically operated aerosol generating device is capable of generating a fluctuating electromagnetic field having a frequency between 1 MHz and 30 MHz, for example between 1 MHz and 10 MHz, for example between 5 MHz and 7 MHz.

[0030] The aerosol-generating article may be in the form of a rod.As used herein with reference to the present invention, the term "rod" is intended to denote a generally cylindrical element of substantially circular, oval or elliptical cross-section.

[0031] As used herein, the term "longitudinal" refers to a direction corresponding to the main longitudinal axis of the aerosol-generating article, which direction extends between the upstream end and the downstream end of the aerosol-generating article. As used herein, the terms "upstream" and "downstream" describe the relative position of an element or part of an element of an aerosol-generating article relative to the direction in which an aerosol is transported through the aerosol-generating article during use.

[0032] During use, air is drawn through the aerosol-generating article in the longitudinal direction. The term "transverse" refers to a direction perpendicular to the longitudinal axis. Unless otherwise stated, any reference to a "section" of an aerosol-generating article or component of an aerosol-generating article refers to a cross-section.

[0033] The term "length" refers to the dimension of a component of an aerosol-generating article in the longitudinal direction. For example, it may be used to refer to the dimension of a strip or an elongated tubular element in the longitudinal direction.

[0034] The term "aerosol former" is used herein to describe a compound that, when volatilized, can aid in the aerosol delivery of other vaporized compounds released upon heating of an aerosol-generating substrate, such as nicotine and flavoring agents. Suitable aerosol formers for inclusion in an aerosol-forming composition are known in the art and include, but are not limited to: polyols, such as triethylene glycol, propylene glycol, 1,3-butylene glycol, and glycerol; esters of polyols, such as glycerol mono-, di-, or triacetate; and aliphatic esters of mono-, di-, or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate.

[0035] The term "twist" is used herein to describe a susceptor material strand that is repeatedly turned or wrapped around the longitudinal axis of the susceptor assembly. More specifically, in the context of the present invention, the term "twist" is used to describe an arrangement in which a susceptor material strand is helically laid around the longitudinal axis of the susceptor assembly.

[0036] The expression "twisted together with at least one susceptor material strand" is used to describe that the aerosol generating strand is similarly rotated repeatedly about the longitudinal axis of the susceptor assembly and about a single susceptor material strand or two or more susceptor material strands, so that the aerosol generating strand is effectively sandwiched between and held in place by two or more susceptor material strands.

[0037] Figure 1 and 2 Two such configurations of susceptor assemblies for use in aerosol-generating articles according to the present invention are schematically shown. Figure 1 In FIG. 1 , a single aerosol generating strand is twisted together with two strands of susceptor material. For simplicity, only the path of the aerosol generating strand is shown by the dotted line. Figure 2 In FIG. 1 , a single aerosol generating ply is twisted together with three plies of susceptor material. The dot-dash line shows the path of a portion of the aerosol generating ply sandwiched between adjacent plies of susceptor material.

[0038] These types of arrangements involving two or more strands have similarities to the arrangements of "cord ropes". Cord ropes are formed from several strands of metal wire twisted into a helix in a pattern called lay rope, thereby forming a composite rope. Larger diameter cord ropes are composed of multiple strands of such lay ropes in a pattern called "cable lay".

[0039] Accordingly, certain geometric parameters of susceptor components of aerosol-generating articles according to the present invention are identified and described herein with similar nomenclature.

[0040] For example, the term "strand helical axis" may be used to describe the centroidal axis about which the strands are helically wound to form the susceptor assembly. In the case of the susceptor assembly of the present invention, it corresponds to the longitudinal axis of the susceptor assembly. The positive direction of the axis is defined as the direction in which the helix advances. For example, the "strand helical axis" may be parallel or coaxial with the longitudinal direction of the aerosol-generating article.

[0041] The term "helix angle" (α w ) describes the angle between the tangent vector at any point along the helix axis (in the direction of the helix) and the plane perpendicular to the helix axis and passing through the point.

[0042] As briefly described above, in an aerosol-generating article according to the present invention, a susceptor assembly is provided, the susceptor assembly comprising at least one susceptor material strand and an aerosol-generating element, the aerosol-generating element comprising at least one porous non-tobacco material strand carrying an aerosol-forming composition, the aerosol-forming composition comprising at least 35% by weight of an aerosol-forming agent.

[0043] At least one susceptor material strand is twisted so as to be helically laid about a longitudinal axis of the susceptor assembly.At least one aerosol generating strand is twisted with at least one susceptor material strand.

[0044] In a preferred embodiment, the at least one or more susceptor material strands comprise two or more susceptor material strands twisted together such that the two or more susceptor material strands are laid helically around the longitudinal axis of the susceptor assembly, and the at least one aerosol generating strand is twisted with the two or more susceptor material strands. Such embodiments have the following benefits: when portions of the at least one aerosol generating strand are arranged between adjacent portions of the two or more susceptor material strands, the at least one aerosol generating strand may be more securely held in place. Thus, the efficiency of heat transfer from the susceptor material strands to the aerosol generating strand may be maximized. Thus, the release of the volatilized aerosol-forming agent may start quickly during the first moment of use of the aerosol generating article. This may be very effective in counteracting the cold suction effect.

[0045] In some embodiments where at least one aerosol generating ply is coupled to two or more susceptor material plies, the at least one aerosol generating ply is also laid helically about the longitudinal axis of the susceptor assembly and is held in place by being sandwiched between at least two of the two or more susceptor material plies. This type of arrangement is Figure 1 and 2By adjusting the number of aerosol generating plies and susceptor material plies in the susceptor assembly, it is possible to change the percentage of the surface area of ​​the one or more aerosol generating plies that is exposed relative to the percentage of the surface area of ​​the one or more aerosol generating plies that is in direct contact with one or more of the susceptor material plies. This can provide a way to fine-tune the amount of heat that is quickly transferred to the one or more aerosol generating plies during use, as well as the location within the aerosol generating article where the volatilized aerosol-forming agent can be more easily released.

[0046] In further embodiments where at least one aerosol generating strand is coupled to two or more strands of susceptor material, the at least one aerosol generating strand extends substantially parallel to the longitudinal axis of the susceptor assembly to define a core of the susceptor assembly, and the two or more strands of susceptor material are helically laid around the at least one aerosol generating strand. This type of arrangement is Figure 3 It is schematically shown in the accompanying drawings.

[0047] In these embodiments, the aerosol generating strands can be more effectively protected from damage that may be caused by friction with other surfaces during the manufacture of the aerosol generating article. This is because the susceptor material strands substantially surround one or more aerosol generating strands, and thus the likelihood of one or more aerosol generating strands coming into contact with other surfaces during manufacture can be reduced. In addition, depending on the number, size, and angle of its strand spirals, the coverage of one or more aerosol generating strands over a portion of the susceptor material strands at the core of the susceptor assembly can be greater or less, such that a relatively small portion of the surface area of ​​one or more aerosol generating strands may be exposed.

[0048] In aerosol-generating articles according to the invention, at least one strand of susceptor material is a metal strip, filament, pin or wire.

[0049] The aerosol-forming composition is preferably adsorbed, coated, impregnated or otherwise loaded onto a porous non-tobacco material, which preferably acts as an inert carrier. In other words, preferably, the porous non-tobacco material cannot release volatile substances into the aerosol formed during use.

[0050] In some embodiments, the porous material is provided in the form of a fiber strand.Preferably, the fiber strand comprises fibers selected from the group consisting of cotton fibers, cellulose fibers, recycled natural fibers (including natural fibers such as those derived from wood pulp), and combinations thereof.

[0051] As briefly described above, the aerosol-forming composition comprises at least 35% by weight of an aerosol-forming agent. Preferably, the aerosol-forming composition comprises at least 40% by weight of an aerosol-forming agent. More preferably, the aerosol-forming composition comprises at least 45% by weight of an aerosol-forming agent. Even more preferably, the aerosol-forming composition comprises at least 50% by weight of an aerosol-forming agent.

[0052] In particularly preferred embodiments, the aerosol-forming composition comprises at least 55 wt% aerosol-former, preferably at least 60 wt% aerosol-former, more preferably at least 70 wt% aerosol-former.

[0053] The aerosol-forming composition may comprise up to 95 wt % aerosol-forming agent, and preferably comprises less than or equal to 90 wt % aerosol-forming agent, more preferably less than or equal to 85 wt % aerosol-forming agent, even more preferably less than or equal to 80 wt % aerosol-forming agent.

[0054] In some embodiments, the aerosol-forming composition comprises 35% to about 90% by weight of an aerosol-forming agent, preferably 40% to about 90% by weight of an aerosol-forming agent, more preferably 45% to about 90% by weight of an aerosol-forming agent, and even more preferably 50% to about 90% by weight of an aerosol-forming agent. In other embodiments, the aerosol-forming composition comprises 35% to about 85% by weight of an aerosol-forming agent, preferably 40% to about 85% by weight of an aerosol-forming agent, more preferably 45% to about 85% by weight of an aerosol-forming agent, and even more preferably 50% to about 85% by weight of an aerosol-forming agent. In further embodiments, the aerosol-forming composition comprises 35% to about 80% by weight of an aerosol-forming agent, preferably 40% to about 80% by weight of an aerosol-forming agent, more preferably 45% to about 80% by weight of an aerosol-forming agent, and even more preferably 50% to about 80% by weight of an aerosol-forming agent.

[0055] Preferably, the aerosol former is selected from triethylene glycol, propylene glycol, 1,3-butylene glycol, glycerol and mixtures thereof. In a particularly preferred embodiment, the aerosol former is glycerol.

[0056] Additionally, the aerosol-forming composition may comprise nicotine.

[0057] As used herein with reference to the present invention, the term "nicotine" is used to describe nicotine, nicotine base or nicotine salt. In embodiments where the solid aerosol generating matrix comprises nicotine base or nicotine salt, the amount of nicotine recorded herein is the amount of free base nicotine or the amount of protonated nicotine, respectively.

[0058] The aerosol-forming composition may comprise natural nicotine, or synthetic nicotine, or a combination of natural and synthetic nicotine.

[0059] The aerosol-forming composition may have a nicotine content of greater than or equal to 0.5 wt%, greater than or equal to 1 wt%, greater than or equal to 1.5 wt%, or greater than or equal to 2 wt%.

[0060] The aerosol-forming composition may have a nicotine content of less than or equal to 10 wt %, less than or equal to 8 wt %, less than or equal to 6 wt %, or less than or equal to 4 wt %.

[0061] The aerosol-forming composition may have a nicotine content of between 0.5 wt % and 10 wt %, between 0.5 wt % and 8 wt %, between 0.5 wt % and 6 wt %, or between 0.5 wt % and 4 wt %.

[0062] The aerosol-forming composition may have a nicotine content of between 1 wt % and 10 wt %, between 1 wt % and 8 wt %, between 1 wt % and 6 wt %, or between 1 wt % and 4 wt %.

[0063] The aerosol-forming composition may have a nicotine content of between 1.5 wt % and 10 wt %, between 1.5 wt % and 8 wt %, between 1.5 wt % and 6 wt %, or between 1.5 wt % and 4 wt %.

[0064] The aerosol-forming composition may have a nicotine content of between 2% and 10% by weight, between 2% and 8% by weight, between 2% and 6% by weight, or between 2% and 4% by weight.

[0065] In some embodiments, the aerosol-forming composition may comprise one or more carboxylic acids.

[0066] The aerosol-forming composition may comprise a plurality of carboxylic acids. That is, the aerosol-forming composition may comprise two or more carboxylic acids. For example, the aerosol-forming composition may comprise two carboxylic acids, three carboxylic acids, four carboxylic acids, or five carboxylic acids.

[0067] The aerosol-forming composition may comprise one or more carboxylic acids that do not contain any non-carboxy hydroxyl groups.

[0068] As used herein with reference to the present invention, the term "non-carboxy hydroxyl group" is used to describe a hydroxyl group that does not form part of a carboxyl group.

[0069] The aerosol-forming composition may comprise one or more carboxylic acids having a pKa in water at 25°C of less than or equal to 3.5.

[0070] As used herein with reference to the present invention, the term "carboxylic acid having a pKa in water at 25°C of less than or equal to 3.5" is used to describe monoprotic carboxylic acids having a pKa in water at 25°C of less than or equal to 3.5 and polyprotic carboxylic acids having a pKa in water at 25°C of less than or equal to 3.5.

[0071] The aerosol-forming composition may comprise a plurality of carboxylic acids having a pKa in water of less than or equal to 3.5 at 25° C. For example, the solid aerosol-generating substrate may comprise fumaric acid and maleic acid.

[0072] The aerosol-forming composition may comprise one or more carboxylic acids having a pKa in water at 25°C of greater than or equal to 3.6.

[0073] As used herein with reference to the present invention, the term "carboxylic acid having a pKa greater than or equal to 3.6 in water at 25°C" is used to describe monoprotic carboxylic acids having a pKa greater than or equal to 3.6 in water at 25°C and polyprotic carboxylic acids having a pKa greater than or equal to 3.6 in water at 25°C.

[0074] For example, the aerosol-forming composition may comprise one or more carboxylic acids selected from acetic acid, benzoic acid, lactic acid and levulinic acid.

[0075] The aerosol-forming composition may comprise a plurality of carboxylic acids having a pKa in water greater than or equal to 3.6 at 25° C. For example, the aerosol-forming composition may comprise benzoic acid and lactic acid.

[0076] The aerosol-forming composition may comprise one or more carboxylic acids having a pKa in water at 25°C less than or equal to 3.5 and one or more carboxylic acids having a pKa in water at 25°C greater than or equal to 3.6.

[0077] For example, the aerosol-forming composition may comprise one or more carboxylic acids selected from fumaric acid, maleic acid and malic acid and one or more carboxylic acids selected from acetic acid, benzoic acid, lactic acid and levulinic acid.

[0078] For example, the aerosol-forming composition may comprise fumaric acid and one or more carboxylic acids selected from acetic acid, benzoic acid, lactic acid and levulinic acid.

[0079] Preferably, the aerosol-forming composition comprises one or more carboxylic acids selected from fumaric acid, maleic acid and malic acid.

[0080] More preferably, the aerosol-forming composition comprises one or more carboxylic acids selected from fumaric acid and maleic acid.

[0081] Most preferably, the aerosol-forming composition comprises fumaric acid.

[0082] The aerosol-forming composition may have a total carboxylic acid content greater than or equal to 0.5 wt%.

[0083] As used herein with reference to the present invention, the term "total carboxylic acid content" is used to describe the combined content of all carboxylic acids in the aerosol-forming composition. For example, in the case where the solid aerosol-generating substrate comprises a plurality of carboxylic acids consisting of benzoic acid and fumaric acid, the term "total carboxylic acid content" describes the combined benzoic acid content and fumaric acid content of the solid aerosol-generating substrate.

[0084] The aerosol-forming composition may have a total carboxylic acid content of greater than or equal to 1 wt %, greater than or equal to 1.5 wt %, or greater than or equal to 2 wt %.

[0085] The aerosol-forming composition may have a total carboxylic acid content of less than or equal to 8 wt %, less than or equal to 6 wt %, or less than or equal to 4 wt %.

[0086] The aerosol-forming composition may have a total carboxylic acid content of between 0.5 wt % and 8 wt %, between 0.5 wt % and 6 wt %, or between 0.5 wt % and 4 wt %.

[0087] The aerosol-forming composition may have a total carboxylic acid content of between 1 wt % and 8 wt %, between 1 wt % and 6 wt %, or between 1 wt % and 4 wt %.

[0088] The aerosol-forming composition may have a total carboxylic acid content of between 1.5 wt % and 8 wt %, between 1.5 wt % and 6 wt %, or between 1.5 wt % and 4 wt %.

[0089] The aerosol-forming composition may have a total carboxylic acid content of between 2 wt% and 8 wt%, between 2 wt% and 6 wt%, or between 2 wt% and 4 wt%.

[0090] The aerosol-forming composition may comprise one or more cellulose-based agents.

[0091] As used herein with reference to the present invention, the term "cellulose-based agent" is used to describe a cellulosic material. Examples of cellulose-based agents include cellulose-based film formers, cellulose-based strengthening agents, and cellulose-based binding agents.

[0092] The aerosol-forming composition may comprise a plurality of cellulose-based agents. That is, the solid aerosol-generating substrate may comprise two or more cellulose-based agents. For example, the aerosol-forming composition may comprise two cellulose-based agents, three cellulose-based agents, four cellulose-based agents, or five cellulose-based agents.

[0093] The aerosol-forming composition may have a total cellulose-based agent content of greater than or equal to 25 wt%, or greater than or equal to 30 wt%.

[0094] As used herein with reference to the present invention, the term "total cellulose-based agents" is used to describe the combined content of all cellulose-based agents in the aerosol-forming composition. For example, where the aerosol-forming composition comprises a plurality of cellulose-based agents consisting of a cellulose-based film-forming agent, a cellulose-based strengthening agent, and a cellulose-based binding agent, the term "total cellulose-based agents content" describes the combined cellulose-based film-forming agent content, the cellulose-based strengthening agent content, and the cellulose-based binding agent content of the aerosol-forming composition.

[0095] In some embodiments, the aerosol-forming composition may have a total cellulose-based agent content greater than or equal to 35% by weight.

[0096] The diameter of the at least one susceptor material strand may be at least 0.25 mm. Preferably, the diameter of the at least one susceptor material strand is at least 0.3 mm. More preferably, the diameter of the at least one susceptor material strand is at least 0.4 mm. Even more preferably, the diameter of the at least one susceptor material strand is at least 0.5 mm.

[0097] The diameter of the at least one susceptor material strand may be up to 2 mm. Preferably, the diameter of the at least one susceptor material strand is less than or equal to 1.5 mm. More preferably, the diameter of the at least one susceptor material strand is less than or equal to 1.25 mm. Even more preferably, the diameter of the at least one susceptor material strand is less than or equal to 1 mm.

[0098] In some embodiments, the diameter of at least one susceptor material strand is from 0.3 mm to 1.5 mm, preferably from 0.3 mm to 1.25 mm, more preferably from 0.3 mm to 1 mm. In other embodiments, the diameter of at least one susceptor material strand is from 0.4 mm to 1.5 mm, preferably from 0.4 mm to 1.25 mm, more preferably from 0.4 mm to 1 mm. In further embodiments, the diameter of at least one susceptor material strand is from 0.5 mm to 1.5 mm, preferably from 0.5 mm to 1.25 mm, more preferably from 0.5 mm to 1 mm.

[0099] The diameter of the at least one aerosol generating pluton may be at least 0.5 mm. Preferably, the diameter of the at least one aerosol generating pluton is at least 0.6 mm. More preferably, the diameter of the at least one aerosol generating pluton is at least 0.7 mm.

[0100] The diameter of at least one aerosol generating ply may be up to 2 mm. Preferably, the diameter of at least one aerosol generating ply is less than or equal to 1.5 mm. More preferably, the diameter of at least one aerosol generating ply is less than or equal to 1.25 mm. Even more preferably, the diameter of at least one aerosol generating ply is less than or equal to 1 mm.

[0101] In some embodiments, the diameter of at least one aerosol generating strand is 0.5 mm to 1.5 mm, preferably 0.5 mm to 1.25 mm, more preferably 0.5 mm to 1 mm. In other embodiments, the diameter of at least one aerosol generating strand is 0.6 mm to 1.5 mm, preferably 0.6 mm to 1.25 mm, more preferably 0.6 mm to 1 mm. In other embodiments, the diameter of at least one aerosol generating strand is 0.7 mm to 1.5 mm, preferably 0.7 mm to 1.25 mm, more preferably 0.7 mm to 1 mm.

[0102] In certain embodiments, the strand helix angle of at least one susceptor material strand is at least 20 degrees. Preferably, the strand helix angle of at least one susceptor material strand is at least 30 degrees. More preferably, the strand helix angle of at least one susceptor material strand is at least 35 degrees. Even more preferably, the strand helix angle of at least one susceptor material strand is at least 40 degrees. In particularly preferred embodiments, the strand helix angle of at least one susceptor material strand is at least 45 degrees.

[0103] The strand helix angle of at least one susceptor material strand is less than or equal to 80 degrees. Preferably, the strand helix angle of at least one susceptor material strand is less than or equal to 70 degrees. More preferably, the strand helix angle of at least one susceptor material strand is less than or equal to 65 degrees. Even more preferably, the strand helix angle of at least one susceptor material strand is less than or equal to 60 degrees. In a particularly preferred embodiment, the strand helix angle of at least one susceptor material strand is less than or equal to 55 degrees.

[0104] In some embodiments, the strand helix angle of at least one susceptor material strand is from 20 to 80 degrees, preferably from 20 to 70 degrees, more preferably from 20 to 65 degrees, even more preferably from 20 to 60 degrees, and most preferably from 20 to 55 degrees.

[0105] In some embodiments, the strand helix angle of at least one susceptor material strand is from 30 to 80 degrees, preferably from 30 to 70 degrees, more preferably from 30 to 65 degrees, even more preferably from 30 to 60 degrees, and most preferably from 30 to 55 degrees.

[0106] In some embodiments, the strand helix angle of at least one susceptor material strand is from 35 to 80 degrees, preferably from 35 to 70 degrees, more preferably from 35 to 65 degrees, even more preferably from 35 to 60 degrees, and most preferably from 35 to 55 degrees.

[0107] In some embodiments, the strand helix angle of at least one susceptor material strand is from 40 to 80 degrees, preferably from 40 to 70 degrees, more preferably from 40 to 65 degrees, even more preferably from 40 to 60 degrees, and most preferably from 40 to 55 degrees.

[0108] In some embodiments, the strand helix angle of at least one susceptor material strand is between 45 and 80 degrees, preferably between 45 and 70 degrees, more preferably between 45 and 65 degrees, even more preferably between 45 and 60 degrees, and most preferably between 45 and 55 degrees. Without wishing to be bound by theory, it is understood that by laying down at least one susceptor material strand at a strand helix angle falling within the above range, a susceptor assembly having particularly good structural strength can advantageously be provided, and wherein the at least one aerosol generating strand is held in place very stably. In addition, by laying down at least one susceptor material strand at a strand helix angle falling within the above range, the at least one aerosol generating strand can advantageously be protected from potential damage caused by friction during manufacture and handling of the susceptor assembly. At the same time, in one such susceptor assembly, satisfactory heat transfer from one or more susceptor material strands to at least one aerosol generating strand can be combined with particularly efficient mass transfer on the basis of aerosol generation and delivery to a consumer. With a helix angle in the range of about 20 degrees, there is more material per unit length, thereby providing the ability to generate more heat. With a helix angle in the range of about 80 degrees, manufacturing costs are reduced because there is less material per unit length.

[0109] In some embodiments, the aerosol-generating article comprises an aerosol-generating strip comprising a primary aerosol-generating substrate. The susceptor assembly is thermally coupled to the primary aerosol-generating substrate. In more detail, this is achieved by having the susceptor assembly extend longitudinally within the aerosol-generating strip and be embedded within the aerosol-generating substrate.

[0110] For example, the aerosol generating article can include a sheet of homogenized tobacco material, which gathers to form a strip extending along the longitudinal axis of the aerosol generating article. The sensor assembly can be embedded in the gathered sheet of homogenized tobacco material. As an alternative, the aerosol generating article can include a strip, which includes a shredded filler obtained by cutting tobacco leaf material or remaking or homogenizing tobacco material. The sensor assembly can be embedded in the shredded filler, for example to be surrounded by the shredded filler.

[0111] In these embodiments, the strip including the aerosol generating substrate provides an additional aerosol source, which during use will generally reach a temperature sufficient to release the aerosol material later than the aerosol-forming composition carried by at least one aerosol generating strand in the susceptor assembly. Therefore, by adjusting the content of the aerosol-forming composition in the aerosol generating article relative to the content of the additional aerosol generating substrate, and by changing the formulation of the aerosol-forming composition or the properties and composition of the additional aerosol generating substrate, an aerosol generating article can be provided that can be associated with a specially customized aerosol delivery curve (including a flavor delivery curve). In particular, the release of the aerosol from the susceptor assembly can be fine-tuned to offset the possible cold suction effect associated with the additional aerosol generating substrate. For example, the release of the aerosol from the susceptor assembly can be fine-tuned depending on one or more of the following: the properties and composition of the additional aerosol generating substrate; the geometry of the strip including the additional aerosol generating substrate; the heating curve over time, etc.

[0112] In certain embodiments, the susceptor assembly further comprises one or more spacer elements of a non-conductive material, the one or more spacer elements being configured to create a gap between two adjacent ones of the two or more susceptor material strands such that respective portions of two adjacent ones of the two or more susceptor material strands are at a predetermined distance from one another.

[0113] The aerosol-generating article may comprise a secondary aerosol-generating substrate disposed in at least one of the predetermined gaps.

[0114] This may advantageously allow for a more efficient use of the volume occupied by the susceptor assembly within the aerosol-generating article, as a greater portion of this volume may be occupied by active material that contributes to the overall aerosol generation. In addition, by selecting a secondary aerosol-generating substrate that is adapted to release the volatile material at a different temperature than the aerosol-generating puff and the aerosol-forming agent contained therein, it may be possible to further expand the range of flavor release profiles that may be provided to the consumer. For example, the secondary aerosol-generating substrate may be adapted to release the volatile material with a certain delay compared to the aerosol-generating puff and the aerosol-forming agent contained therein.

[0115] In those embodiments where the susceptor assembly is thermally coupled to the primary aerosol generating substrate, the secondary aerosol generating substrate may, for example, be adapted to release the volatile material prior to or substantially simultaneously with the primary aerosol generating substrate. This enables very fine tuning of aerosol release and delivery to the consumer, wherein a large number of different combinations and flavors and delivery profiles can be designed by controlling when and in what amounts different aerosol materials are released from various sources contained in the aerosol generating article.

[0116] In some of these embodiments, the one or more spacer elements comprise beads disposed on one of the two or more susceptor material strands.

[0117] The beads may provide a spacer element that is easily combined with two or more strands of susceptor material during manufacture of the susceptor assembly. For example, the beads may be provided as drops of heat resistant glue deposited onto the strands of susceptor material. One such bead may have the benefit of a substantially smooth outer surface, which is desirable because it is less likely to damage the aerosol generating strand when it is combined with the strand of susceptor material bearing the bead.

[0118] Preferably, the equivalent diameter of the bead is at least 1.5 times the diameter of the strand of susceptor material. More preferably, the equivalent diameter of the bead is at least 2 times the diameter of the strand of susceptor material.

[0119] In some embodiments, the beads may have an equivalent diameter of at least 0.75 mm, preferably at least 1 mm, more preferably at least 1.25 mm, and even more preferably at least 1.5 mm.

[0120] In some embodiments, the equivalent diameter of the beads may be less than or equal to 3 mm, preferably less than or equal to 2.5 mm, and more preferably less than or equal to 2 mm.

[0121] In the case of beads having an equivalent diameter falling within the above range, the gaps created between adjacent strands can be readily filled with additional aerosol-generating substrate.

[0122] In a preferred embodiment, the one or more spacer elements comprise a plurality of beads, the beads being equally spaced along the length of one of the two or more susceptor material strands.

[0123] Such evenly distributed beads force the strands to be regularly spaced and thus provide a predetermined pattern of interstices along the length of one or more strands, the interstices being suitable for receiving an aerosol-generating substrate, for example in the form of a gel.

[0124] In others of these embodiments, the one or more spacer elements comprise a plate comprising one or more openings, wherein the plate is arranged transverse to a longitudinal axis of the susceptor assembly, and each of the one or more openings is adapted to receive a corresponding one of the two or more susceptor material strands.

[0125] Using one such plate as a spacer element may have the benefit that by controlling the size and mutual arrangement of the openings extending through the plate, it is possible to better control how the different strands in the susceptor assembly are positioned relative to each other.

[0126] Preferably, the plate is circular and the one or more openings are equally spaced about the longitudinal axis.

[0127] The use of a substantially circular plate may be advantageous as it is highly compatible with the pseudo-cylindrical shape of the susceptor assembly and, more importantly, with the pseudo-cylindrical shape of the strip-shaped aerosol-generating article incorporating the susceptor assembly. By having the openings equally spaced about the longitudinal axis of the plate, the arrangement of the strands within the susceptor assembly relative to the longitudinal axis of the susceptor assembly may advantageously be better controlled. This may help ensure more uniform heat generation during use, as well as more uniform heat transfer and aerosol generation and delivery during use.

[0128] The plate may include a central opening extending through the plate coaxially with the longitudinal axis.

[0129] Providing a spacer plate with a central opening may be desirable, particularly if such a central opening is used to receive an aerosol generating strand, particularly in those embodiments in which the aerosol generating strand extends at the core of the susceptor assembly. In this case, the central opening of the spacer plate may be used to stably hold the aerosol generating strand at the core position along the longitudinal axis of the susceptor assembly.

[0130] In an embodiment, an aerosol-generating article for generating an inhalable aerosol upon heating according to the present invention may comprise a susceptor assembly, wherein the susceptor assembly comprises at least one susceptor material strand, the at least one susceptor material strand being twisted so as to be helically laid about the longitudinal axis of the susceptor assembly; and an aerosol-generating element, the aerosol-generating element comprising at least one aerosol-forming strand. The susceptor assembly further comprises one or more spacer elements of a non-conductive material, the one or more spacer elements being configured to create a gap between two adjacent susceptor material strands of the at least one susceptor material strand and at least one aerosol-forming strand of the aerosol-generating element, such that two adjacent susceptor material strands of the at least one susceptor material strand and corresponding portions of the at least one aerosol-forming strand of the aerosol-generating element are at a predetermined distance from each other. The aerosol-generating article according to the present invention may further comprise a downstream section at a position downstream of the susceptor assembly. For example, in those embodiments in which the aerosol-generating article comprises a strip comprising an aerosol-generating substrate, the susceptor assembly being thermally coupled to the aerosol-generating substrate, e.g. by being embedded in the aerosol-generating substrate, the downstream section may be at a position downstream of the strip.

[0131] The downstream section may include one or more downstream elements.

[0132] The downstream section may comprise a hollow section between the mouth end of the aerosol-generating article and the susceptor assembly.The hollow section may comprise a hollow tubular element.

[0133] As used herein, terms such as "hollow tubular segment" and "hollow tubular element" are used to refer to a generally elongated element that defines an inner cavity or airflow passage along its longitudinal axis. In particular, the term "tubular" is used to refer to an element or segment having a substantially cylindrical cross-section and defining at least one airflow conduit that establishes uninterrupted fluid communication between an upstream end of the tubular element or segment and a downstream end of the tubular element or segment. However, it should be understood that alternative geometries (e.g., alternative cross-sectional shapes) of the tubular element or segment may be possible.

[0134] In the context of the present invention, the hollow tubular segment or hollow tubular element provides an unrestricted flow passage.This means that the hollow tubular segment or hollow tubular element provides a negligible level of resistance to draw (RTD).

[0135] The resistance to draw (RTD) of an aerosol-generating article or a component thereof (such as a segment of filter material) can be assessed as the negative pressure that must be applied to the downstream end of the article or component in order to maintain a steady volumetric air flow of 17.5 ml / s through the article or component. The skilled person can find further details on the measurement method, test conditions, etc. in ISO 6565:2015 (2015).

[0136] The downstream section may include a support element positioned downstream of the susceptor assembly. For example, the support element may be disposed immediately downstream of the susceptor assembly and preferably arranged adjacent to the susceptor assembly or to a segment in which the susceptor assembly may be disposed, such as a strip of aerosol-generating substrate. The support element may, for example, be in the form of a cellulose acetate rod. The support element itself may be hollow.

[0137] The downstream section may include an aerosol-cooling element positioned downstream of the susceptor assembly. The aerosol-cooling element may be disposed immediately downstream of the susceptor assembly or immediately downstream of a segment in which the susceptor assembly may be disposed (such as a strip of an aerosol-generating substrate). Alternatively, another element may be disposed between the susceptor assembly or a segment including the susceptor assembly and the aerosol-cooling element. For example, a support element as described above may be positioned between the susceptor assembly or a segment including the susceptor assembly and the aerosol-cooling element. In this case, all three elements may be arranged in an adjacent relationship along the longitudinal axis of the aerosol-generating article.

[0138] In certain embodiments, the aerosol-cooling element may be provided in the form of a hollow tubular element comprising a ventilation zone disposed at a location along the hollow tubular element and configured to allow air to enter from the external environment when a consumer inhales the aerosol-generating article.

[0139] The downstream section may include a mouthpiece element. The mouthpiece element may be positioned at the downstream end of the aerosol-generating article, and thus downstream not only of the susceptor assembly or a segment comprising the susceptor assembly, but also downstream of any other optional elements among the optional elements mentioned above. The mouthpiece element extends all the way to the mouth end of the aerosol-generating article.

[0140] Preferably, the mouthpiece element comprises at least one mouthpiece filter segment of fibrous filter material. Suitable fibrous filter materials will be known to the skilled person. Particularly preferably, at least one mouthpiece filter segment comprises a cellulose acetate filter segment formed from cellulose acetate tow.

[0141] In certain embodiments of the present invention, the downstream section may include a mouth end cavity at the downstream end downstream of the mouthpiece filter segment as described above. The mouth end cavity may be defined by a hollow tubular element disposed at the downstream end of the mouthpiece. The mouth end cavity may be defined by an outer wrapper of the mouthpiece element, wherein the outer wrapper extends from the mouthpiece element in the downstream direction.

[0142] The mouthpiece element may optionally include a flavoring agent, which may be provided in any suitable form. For example, the mouthpiece element may include one or more capsules, beads or particles of a flavoring agent, or one or more threads or filaments loaded with a flavoring agent.

[0143] Preferably, the mouthend element has a low particle filtration efficiency.

[0144] Preferably, the mouthpiece is formed from sections of fibrous filter material.

[0145] Preferably, the mouthend element is defined by a stick wrap.

[0146] Aerosol-generating articles according to the invention may include an upstream section at a position upstream of the susceptor assembly. For example, in those embodiments in which the aerosol-generating article comprises a strip comprising an aerosol-generating substrate to which the susceptor assembly is thermally coupled, e.g. by being embedded in the aerosol-generating substrate, the upstream section may be at a position upstream of the strip.

[0147] The upstream section may include one or more upstream elements. In some embodiments, the upstream section may include an upstream element arranged immediately upstream of the susceptor assembly or a segment including the susceptor assembly.

[0148] The upstream element may provide an improved appearance to the upstream end of the aerosol-generating article. In addition, if desired, the upstream element may be used to provide information about the aerosol-generating article, such as information about the brand, flavor, contents or details of the aerosol-generating device with which the article is intended to be used.

[0149] The upstream element may be a porous rod element, such as a rod of cellulose acetate tow.

[0150] As briefly described above, an aerosol generating system according to the present invention comprises a heating device and an aerosol generating article conforming to the preceding description.

[0151] Therefore, the present invention also relates to an aerosol generating system comprising such a heating device (eg an electrically heated aerosol generating device) and an aerosol generating article including a susceptor assembly as described above.

[0152] Examples of suitable aerosol generating devices will be known to those skilled in the art. In general, a suitable aerosol generating device will include a cavity (i.e., a heating chamber) for receiving the aerosol generating article, and one or more inductor elements adapted to generate a fluctuating electromagnetic field within the cavity. In addition, a suitable aerosol generating device typically includes a power source connected to the one or more inductor elements; and a control element configured to control the supply of power from the power source to the one or more inductor elements.

[0153] Each inductor element may comprise one or more coils that generate a fluctuating electromagnetic field.The one or more coils may surround the cavity.

[0154] Preferably, the aerosol generating device is capable of generating a fluctuating electromagnetic field between 1 and 30 MHz, for example between 2 and 10 MHz, for example between 5 and 7 MHz.

[0155] Preferably, the device is capable of generating a fluctuating electromagnetic field having a field strength (H field) between 1 and 5 kA / m, such as between 2 and 3 kA / m, such as about 2.5 kA / m.

[0156] Preferably, the aerosol generating device is a portable or handheld aerosol generating device that is comfortable for a user to hold between the fingers of a single hand.

[0157] The aerosol generating device may be substantially cylindrical in shape.

[0158] The aerosol generating device may have a length of between about 70 mm and about 120 mm.

[0159] The power source can be any suitable power source, such as a DC voltage source, such as a battery. In one embodiment, the power source is a lithium-ion battery. Alternatively, the power source can be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery such as lithium-cobalt, lithium iron phosphate, lithium titanate, or a lithium-polymer battery.

[0160] The control element may be a simple switch. Alternatively, the control element may be an electrical circuit and may include one or more microprocessors or microcontrollers.

[0161] Features described in relation to one or more aspects may be equally applicable to other aspects of the invention.In particular, features described in relation to the susceptor assembly of an aerosol-generating article may be equally applicable to an aerosol-generating system.

[0162] The invention is defined in the claims. However, a non-exhaustive list of non-limiting examples is provided below. Any one or more features of these examples may be combined with any one or more features of another example, embodiment or aspect described herein.

[0163] Example Ex1: An aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article comprising: a susceptor component, the susceptor component comprising:

[0164] at least one susceptor material strand twisted so as to be helically laid about a longitudinal axis of the susceptor assembly; and at least one aerosol generating strand, wherein the at least one aerosol generating strand is twisted with the at least one susceptor material strand.

[0165] Example Ex2: An aerosol-generating article according to Ex1, wherein the at least one aerosol-generating ply comprises a ply of porous non-tobacco material carrying an aerosol-forming composition.

[0166] Example Ex3: An aerosol-generating article according to Ex2, wherein the aerosol-forming composition comprises at least 35 wt% of an aerosol former.

[0167] Example Ex4: An aerosol-generating article according to Ex2, wherein the aerosol-forming composition comprises at least 40 wt% of an aerosol former.

[0168] Example Ex5: An aerosol-generating article according to Ex2, wherein the aerosol-forming composition comprises at least 45 wt% of an aerosol former.

[0169] Example Ex6: An aerosol-generating article according to Ex2, wherein the aerosol-forming composition comprises at least 50 wt% of an aerosol former.

[0170] Example Ex7: An aerosol-generating article according to any one of Examples Ex3 to Ex6, wherein the aerosol former is selected from triethylene glycol, propylene glycol, 1,3-butylene glycol, glycerol; glycerol mono-, di- and triacetates; dimethyl dodecanedioate and dimethyl tetradecanedioate.

[0171] Example Ex8: An aerosol generating article according to any of the preceding examples, wherein at least one or more susceptor material strands comprise two or more susceptor material strands twisted together such that the two or more susceptor material strands are spirally laid around the longitudinal axis of the susceptor assembly, and the at least one aerosol generating strand is twisted with the two or more susceptor material strands.

[0172] Example Ex9: An aerosol-generating article according to Ex8, wherein the at least one aerosol-generating ply is also laid helically around the longitudinal axis of the susceptor assembly and is held in place by being sandwiched between at least two of the two or more susceptor material plies.

[0173] Example Ex10: An aerosol-generating article according to Ex8, wherein the at least one aerosol-generating strand extends substantially parallel to the longitudinal axis of the susceptor assembly to define a core of the susceptor assembly, and the two or more strands of susceptor material are helically laid around the at least one aerosol-generating strand.

[0174] Example Ex11: An aerosol-generating article according to any of the preceding examples, wherein the at least one susceptor material strand is a metal strip, filament, pin or wire.

[0175] Example Ex 12: An aerosol-generating article according to any of the preceding examples, wherein the aerosol-forming composition is adsorbed, coated, impregnated or otherwise loaded onto the porous material.

[0176] Example Ex 13: An aerosol-generating article according to any of the preceding examples, wherein the porous material is a fibrous material.

[0177] Example Ex 14: An aerosol-generating article according to any one of the preceding examples, wherein the porous material is provided in the form of a fiber strand.

[0178] Example Ex15: An aerosol-generating article according to Ex14, wherein the fiber strands comprise fibers selected from the group consisting of cotton fibers, cellulose fibers, recycled natural fibers, and combinations thereof.

[0179] Example Ex16: An aerosol-generating article according to any one of the preceding examples, wherein the diameter of the at least one aerosol-generating puff is at least 0.5 mm.

[0180] Example Ex17: An aerosol-generating article according to any one of the preceding examples, wherein the diameter of the at least one aerosol-generating ply is less than or equal to 1.5 mm.

[0181] Example Ex 18: An aerosol-generating article according to any one of the preceding examples, wherein the diameter of the at least one susceptor material strand is at least 0.3 mm.

[0182] Example Ex 19: An aerosol-generating article according to any one of the preceding examples, wherein the diameter of the at least one susceptor material strand is less than or equal to 1.5 mm.

[0183] Example Ex20: An aerosol-generating article according to any of the preceding examples, wherein the strand helix angle of the at least one susceptor material strand is less than 80 degrees.

[0184] Example Ex21: An aerosol-generating article according to any of the preceding examples, wherein the aerosol-generating article comprises an aerosol-generating strip comprising an aerosol-generating substrate; wherein the susceptor assembly is thermally coupled to the first aerosol-generating substrate.

[0185] Example Ex22: An aerosol-generating article according to Ex21, wherein the susceptor component extends longitudinally within the aerosol-generating strip and is embedded within the aerosol-generating substrate.

[0186] Example Ex23: An aerosol-generating article according to any one of Examples Ex Ex8 to Ex22, wherein the susceptor assembly further comprises one or more spacer elements of a non-conductive material, the one or more spacer elements being configured to create a gap between two adjacent susceptor material strands among the two or more susceptor material strands, so that corresponding portions of two adjacent susceptor material strands among the two or more susceptor material strands are at a predetermined distance from each other.

[0187] Example Ex24: An aerosol-generating article according to Ex23, comprising a secondary aerosol-generating substrate disposed in at least one of the predetermined gaps.

[0188] Example Ex25: An aerosol-generating article according to Ex23, wherein the one or more spacer elements comprise beads disposed on one of the two or more susceptor material strands.

[0189] Example Ex26: An aerosol-generating article according to Ex25, wherein the equivalent diameter of the beads is at least 0.75 mm.

[0190] Example Ex27: An aerosol-generating article according to Ex26, wherein the one or more spacer elements comprise a plurality of beads equally spaced along the length of one of the two or more susceptor material strands.

[0191] Example Ex28: An aerosol-generating article according to any one of Examples Ex23 to Ex27, wherein the one or more spacer elements comprise a plurality of beads equally spaced along the length of one of the two or more susceptor material strands.

[0192] Example Ex28: An aerosol generating article according to Ex23 or Ex24, wherein the one or more spacer elements include a plate comprising one or more openings, wherein the plate is arranged transversely to the longitudinal axis of the sensor assembly, and each of the one or more openings is suitable for receiving a corresponding one of the two or more sensor material strands.

[0193] Example Ex29: An aerosol-generating article according to Ex28, wherein the plate is circular and the one or more openings are equally spaced around the longitudinal axis.

[0194] Example Ex30: An aerosol-generating article according to Ex28 or Ex29, wherein the plate comprises a central opening extending through the plate coaxially with the longitudinal axis.

[0195] Example Ex31: An aerosol-generating article according to one of Examples Ex28 to Ex30, wherein the one or more spacer elements comprise a plurality of plates equally spaced along the length of the susceptor assembly, wherein each plate comprises one or more openings.

[0196] Example Ex32: An aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article comprising:

[0197] an aerosol-generating rod comprising a first aerosol-generating substrate; and

[0198] a susceptor assembly thermally coupled to the first aerosol generating substrate;

[0199] The sensor assembly comprises:

[0200] two or more strands of susceptor material, the two or more strands of susceptor material being twisted together such that the two or more strands of susceptor material are helically laid about a longitudinal axis of the susceptor assembly;

[0201] one or more spacer elements of a non-conductive material, the one or more spacer elements being configured to create a gap between two adjacent ones of the two or more susceptor material strands such that respective portions of two adjacent ones of the two or more susceptor material strands are at a predetermined distance from one another;

[0202] and a second aerosol-generating substrate disposed in at least one of the predetermined gaps.

[0203] Example Ex33: An aerosol generating system comprising a heating device and an aerosol generating article according to any one of Examples Ex1 to Ex32.

[0204] Example Ex34: An aerosol-generating article for generating an inhalable aerosol when heated, the aerosol-generating article comprising a susceptor assembly, the susceptor assembly comprising: at least one susceptor material strand, the at least one susceptor material strand being twisted so as to be spirally laid around the longitudinal axis of the susceptor assembly; and an aerosol-generating element, the aerosol-generating element comprising at least one strand; wherein the susceptor assembly further comprises one or more spacer elements of a non-conductive material, the one or more spacer elements being configured to create a gap between two adjacent susceptor material strands in the at least one susceptor material strand and at least one strand of the aerosol-generating element, so that two adjacent susceptor material strands of the at least one susceptor material strand and corresponding portions of at least one strand of the aerosol-generating element are at a predetermined distance from each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0205] Several examples will now be further described with reference to the accompanying drawings, in which:

[0206] Figure 1 is a schematic diagram of a detail of a susceptor assembly in an embodiment of an aerosol-generating article according to the present invention;

[0207] Figure 2 is a schematic diagram of details of a susceptor assembly in another embodiment of an aerosol-generating article according to the present invention;

[0208] Figure 3 is a schematic diagram of details of a susceptor assembly in yet another embodiment of an aerosol-generating article according to the present invention;

[0209] Figure 4 is a schematic diagram of a detail of a susceptor assembly in yet another embodiment of an aerosol-generating article according to the present invention, wherein the susceptor assembly comprises a plurality of bead-shaped spacer elements;

[0210] Figure 5 is a schematic diagram of an alternative spacer element for use in a susceptor assembly of an aerosol-generating article according to the present invention; and

[0211] Figure 6 is a schematic side cross-sectional view of an aerosol-generating article according to the present invention. DETAILED DESCRIPTION

[0212] Figure 1Detail of a susceptor assembly 100 for use in an aerosol generating article according to the present invention is shown in FIG. The susceptor assembly 100 comprises a strand 102 of susceptor material which is twisted so as to be laid helically around the longitudinal axis of the susceptor assembly 100. In addition, the susceptor assembly 100 comprises an aerosol generating strand 104. This is provided in the form of a cotton thread and carries an aerosol forming composition comprising at least 35% by weight of an aerosol forming agent. The aerosol generating strand 104 is twisted with the strand 102 of susceptor material. As shown in FIG. Figure 1 As shown in the figure, the susceptor assembly 100 also includes another susceptor material strand 106, which is also spirally laid around the longitudinal axis of the susceptor assembly and twisted with the susceptor material strand 102 and the aerosol generating strand 104. As shown, several parts of the aerosol generating strand 104 are sandwiched between corresponding parts of the susceptor material strands 102, 106 and are thus held in place within the susceptor assembly. At the same time, this ensures close contact between the susceptor material and the cotton thread carrying the aerosol-forming composition, which facilitates heat transfer towards the aerosol-forming agent carried by the cotton thread during use.

[0213] Figure 2 Another embodiment of a susceptor assembly 200 for use in an aerosol-generating article according to the present invention is shown. Figure 2 The overall structure of the sensor assembly 200 is similar to Figure 1 The overall structure of the susceptor assembly 100 is shown in FIG. 2. However, the susceptor assembly 200 includes three susceptor material strands 202, 206 and 208 twisted together with one aerosol generating strand 204. Figure 2 The dashed lines in indicate portions of the aerosol generating ply 204 that are sandwiched between corresponding portions of the susceptor material plies 202, 206, and 208. This arrangement may provide increased stability to the aerosol generating ply within the susceptor assembly.

[0214] Figure 3 A further embodiment of a susceptor assembly 300 for use in an aerosol-generating article according to the present invention is shown in FIG. Figure 3 The susceptor assembly 300 comprises an aerosol generating strand 304 which defines a core of the susceptor assembly and extends along a longitudinal axis of the susceptor assembly. In addition, the susceptor assembly 300 comprises five susceptor material strands 302, 306, 308, 310 and 312 which are twisted so as to be laid helically around the aerosol generating strand. Thus, the aerosol generating strand 304 at the core is particularly protected from rubbing against other surfaces during manufacture of the aerosol generating article because it is substantially surrounded by the susceptor material strands.

[0215] Figure 4Still another embodiment of a susceptor assembly 400 for use in an aerosol generating article according to the present invention is shown. Figure 1 The sensor assembly 100, Figure 4 The susceptor assembly 400 includes two susceptor material strands 402 and 406 twisted together with an aerosol generating strand 404. Figure 4 The dashed lines in indicate portions of the aerosol generating strand 404 that are sandwiched between respective portions of the susceptor material strands 402 and 406. Spacer elements in the form of beads 408 are arranged substantially equidistantly spaced along the susceptor material strands 402 and are adapted to hold certain portions of the susceptor material strands 402 and 406 at a predetermined distance from each other. Thus, gaps 10 are defined between these portions of the susceptor material strands 402 and 406, which gaps may accommodate additional aerosol generating substrates.

[0216] Figure 5 An alternative form is shown in which the spacer element can be arranged to include Figure 4 In a susceptor element of the type shown in . Figure 4 All three spacer elements 508, 608 and 708 shown in FIG are in the form of plate elements that include one or more openings extending through the plate element. Plate element 508 includes a single opening 512 disposed substantially at the center of plate element 508. Plate element 608 includes two openings 612 equally spaced about the longitudinal axis of the plate element. Plate element 708 includes both a plurality of openings 712 disposed substantially equally spaced about the longitudinal axis of the plate element, and a central opening 714. The one or more openings in each plate element may receive a respective one or more strands forming a susceptor assembly so as to maintain the respective one or more strands at a predetermined distance from one another, or more generally, to control the overall shape and volume of the susceptor assembly.

[0217] Figure 6 An example of an aerosol-generating article 10 according to the present invention is shown.

[0218] Figure 6 The aerosol-generating article 10 shown in FIG. 1 comprises a strip 12 of an aerosol-generating substrate 12 and a downstream section 14 at a position downstream of the strip 12 of the aerosol-generating substrate. In addition, the aerosol-generating article 10 comprises an upstream section 16 at a position upstream of the strip 12 of the aerosol-generating substrate. Thus, the aerosol-generating article 10 extends from an upstream end or distal end 18 to a downstream end or mouth end 20.

[0219] The aerosol-generating article has an overall length of approximately 45 mm.

[0220] The downstream section 14 comprises a support element 22 positioned immediately downstream of the strip 12 of aerosol-generating substrate, the support element 22 being longitudinally aligned with the strip 12. Figure 1 In the embodiment of the invention, the upstream end of the support element 18 abuts the downstream end of the strip 12 of aerosol-generating substrate. In addition, the downstream section 14 includes an aerosol-cooling element 24 positioned immediately downstream of the support element 22, the aerosol-cooling element 24 being longitudinally aligned with the strip 12 and the support element 22. Figure 1 In the embodiment of FIG. 2 , the upstream end of the aerosol-cooling element 24 is adjacent to the downstream end of the support element 22 .

[0221] The support element 22 and the aerosol-cooling element 24 together define a central hollow section 50 of the aerosol-generating article 10. Overall, the central hollow section 50 does not substantially affect the overall RTD of the aerosol-generating article. The RTD of the central hollow section 26 as a whole is substantially 0 mm H2O.

[0222] The support element 22 includes a first hollow tubular segment 26. The first hollow tubular segment 26 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The first hollow tubular segment 26 defines an inner cavity 28 extending from an upstream end 30 of the first hollow tubular segment to a downstream end 32 of the first hollow tubular segment 20. The inner cavity 28 is substantially empty, and thus substantially unrestricted airflow is achieved along the inner cavity 28. The first hollow tubular segment 26, and therefore the support element 22, does not substantially affect the overall RTD of the aerosol generating article 10. In more detail, the RTD of the first hollow tubular segment 26 (which is substantially the RTD of the support element 22) is substantially 0 mm H2O.

[0223] The first hollow tubular section 26 has a length of about 8 mm, an outer diameter of about 7.25 mm, and an inner diameter (D FTS ). Therefore, the thickness of the peripheral wall of the first hollow tubular segment 26 is about 2.67 mm.

[0224] The aerosol-cooling element 24 includes a second hollow tubular segment 34. The second hollow tubular segment 34 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The second hollow tubular segment 34 defines an inner cavity 36 extending from an upstream end 38 of the second hollow tubular segment to a downstream end 40 of the second hollow tubular segment 34. The inner cavity 36 is substantially empty, and thus substantially unrestricted airflow is achieved along the inner cavity 36. The second hollow tubular segment 28 and therefore the aerosol-cooling element 24 do not substantially affect the overall RTD of the aerosol-generating article 10. In more detail, the RTD of the second hollow tubular segment 34 (which is substantially the RTD of the aerosol-cooling element 24) is substantially 0 mm H2O.

[0225] The second hollow tubular segment 34 has a length of about 8 mm, an outer diameter of about 7.25 mm, and an inner diameter (D STS ). Therefore, the thickness of the peripheral wall of the second hollow tubular segment 34 is about 2 mm. Therefore, the inner diameter (D FTS ) and the inner diameter (D STS ) is about 0.75.

[0226] The aerosol-generating article 10 comprises a ventilation zone 60 disposed at a position along the second hollow tubular segment 34. In more detail, the ventilation zone is disposed about 2 mm from the upstream end of the second hollow tubular segment 34. The ventilation level of the aerosol-generating article 10 is about 25%.

[0227] exist Figure 6 In the embodiment of the present invention, the downstream section 14 further comprises a mouthpiece element 42 at a position downstream of the intermediate hollow section 50. In more detail, the mouthpiece element 42 is positioned immediately downstream of the aerosol-cooling element 24. Figure 6 As shown in the Figures, the upstream end of the mouthpiece element 42 is adjacent to the downstream end 40 of the aerosol-cooling element 18.

[0228] The mouthend element 42 is provided in the form of a cylindrical filter segment of low density cellulose acetate.

[0229] The mouthpiece element 42 has a length of about 12 mm and an outer diameter of about 7.25 mm. The RTD of the mouthpiece element 42 is about 12 mm H2O. The ratio of the length of the mouthpiece element 42 to the length of the middle hollow section 50 is about 0.6.

[0230] The rod 12 comprises an aerosol-generating substrate in the form of a gathered sheet of homogenised tobacco material. However, other types of tobacco-containing substrates, such as tobacco cut filler, may replace the gathered sheet of homogenised tobacco material.

[0231] The strip 12 of aerosol-generating substrate had an outer diameter of approximately 7.25 mm and a length of approximately 12 mm.

[0232] The aerosol-generating article 10 further comprises a susceptor assembly 44 of the type described above located within the strip 12 of aerosol-generating substrate. In more detail, the susceptor assembly 44 is arranged substantially longitudinally within the aerosol-generating substrate so as to be generally parallel to the longitudinal direction of the strip 12. Figure 6 As shown in the Figures of FIG. 1 , the susceptor assembly 44 is positioned in a radially central position within the strip and effectively extends along the longitudinal axis of the strip 12 .

[0233] The susceptor assembly 44 extends from the upstream end to the downstream end of the strip 12. In practice, the susceptor assembly 44 has substantially the same length as the strip 12 of aerosol-generating substrate.

[0234] The upstream section 16 comprises an upstream element 46 positioned immediately upstream of the strip 12 of aerosol-generating substrate, the upstream element 46 being longitudinally aligned with the strip 12. Figure 6 In the embodiment of the invention, the downstream end of the upstream element 46 abuts the upstream end of the strip 12 of aerosol-generating substrate. This advantageously prevents the susceptor assembly 44 from being removed. Furthermore, this ensures that the consumer does not accidentally come into contact with the heated susceptor assembly 44 during or after use.

[0235] The upstream element 46 is provided in the form of a cylindrical cellulose acetate rod defined by a rigid wrapper. The upstream element 46 has a length of about 5 mm. The RTD of the upstream element 46 is about 30 mm H2O.

[0236] For the purpose of this specification and the appended claims, unless otherwise indicated, all numbers representing amounts, quantities, percentages, etc. should be understood to be modified by the term "about" in all cases. Moreover, all ranges include disclosed maximum and minimum points, and include any intermediate ranges therein that may be specifically listed or may not be listed herein. Therefore, in this context, the number A is understood to be A±5%A. In this context, the number A may be regarded as including a numerical value within the general standard error for the measurement of the attribute modified by the number A. In some cases used in the appended claims, the number A may deviate from the percentages listed above, provided that the amount of A deviation will not substantially affect the basic features and novel features of the invention claimed for protection. Moreover, all ranges include disclosed maximum and minimum points, and include any intermediate ranges therein that may be specifically listed or may not be listed herein.

Claims

1. An aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article comprising: an aerosol-generating strip comprising an aerosol-generating substrate; A sensor assembly, the sensor assembly comprising: at least one strand of susceptor material twisted so as to be helically laid about a longitudinal axis of the susceptor assembly; and an aerosol-generating element comprising at least one porous strand of non-tobacco material carrying an aerosol-forming composition comprising at least 35% by weight of an aerosol-forming agent, wherein at least one strand of the aerosol generating element is twisted with the at least one strand of susceptor material; Wherein the susceptor assembly is thermally coupled to the aerosol-generating substrate, the susceptor assembly extends longitudinally within the aerosol-generating strip and is embedded within the aerosol-generating substrate.

2. An aerosol generating article according to claim 1, wherein at least one or more strands of susceptor material include two or more strands of susceptor material twisted together so that the two or more strands of susceptor material are spirally laid around the longitudinal axis of the susceptor assembly, and at least one strand of the aerosol generating element is twisted with the two or more strands of susceptor material.

3. An aerosol-generating article according to claim 2, wherein at least one strand of the aerosol-generating element is also laid helically around the longitudinal axis of the susceptor assembly and is held in place by being sandwiched between at least two of the two or more susceptor material strands.

4. An aerosol-generating article according to claim 2, wherein at least one strand of the aerosol-generating element extends substantially parallel to the longitudinal axis of the susceptor assembly to define a core of the susceptor assembly, and the two or more strands of susceptor material are helically laid around at least one strand of the aerosol-generating element.

5. An aerosol-generating article according to any one of the preceding claims, wherein the at least one strand of susceptor material is a metal strip, filament, pin or wire.

6. An aerosol-generating article according to any one of the preceding claims, wherein the aerosol-forming composition is adsorbed, coated, impregnated or otherwise loaded onto the porous material.

7. An aerosol-generating article according to any one of the preceding claims, wherein the at least one susceptor material strand has a diameter of from 0.3 mm to 1.5 mm.

8. An aerosol generating article according to any one of claims 2 to 7, wherein the susceptor assembly further comprises one or more spacer elements of a non-conductive material, the one or more spacer elements being configured to create a gap between two adjacent ones of the two or more susceptor material strands such that respective portions of two adjacent ones of the two or more susceptor material strands are at a predetermined distance from each other.

9. An aerosol-generating article according to claim 8, comprising a secondary aerosol-generating substrate disposed in at least one of the predetermined gaps.

10. An aerosol-generating article according to claim 8, wherein the one or more spacer elements comprise beads disposed on one of the two or more susceptor material strands.

11. An aerosol generating article according to claim 8 or 9, wherein the one or more spacer elements include a plate, the plate including one or more openings, wherein the plate is arranged transversely to the longitudinal axis of the sensor assembly, and each of the one or more openings is suitable for receiving a corresponding one of the two or more sensor material strands.

12. An aerosol-generating article according to claim 11, wherein the plate is circular and the one or more openings are equally spaced about the longitudinal axis.

13. An aerosol-generating article according to claim 11 or 12, wherein the one or more spacer elements comprise a plurality of plates equally spaced along the length of the susceptor assembly, wherein each plate comprises one or more openings.

14. An aerosol-generating system comprising a heating device and an aerosol-generating article according to any one of claims 1 to 13.

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