Aerosol-generating article with internal susceptor

Abstract

To provide an aerosol-generating article comprising an aerosol-forming substrate for generating an inhalable aerosol upon heating.SOLUTION: An aerosol-generating article (10) comprises a plurality of elements assembled in the form of a rod, having a mouth end (70) and a distal end (80) upstream from the mouth end. Said plurality of elements comprises an aerosol-forming substrate (20) located at or towards the distal end of the rod. The elongate susceptor (25) is arranged substantially longitudinally within the rod and is in thermal contact with the aerosol-forming substrate (20). The susceptor allows the article to be consumed using an electrically operated aerosol-generating device having an inductor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This specification relates to an aerosol-generating article that includes an aerosol-forming substrate for generating an inhalable aerosol upon heating. The aerosol-generating article includes an elongated susceptor in thermal contact with the aerosol-forming substrate such that heating of the aerosol-forming substrate can be achieved by induction heating. This specification also relates to a system that includes an aerosol-generating article and an aerosol-generating device having an inductor for heating the aerosol-generating device. [Background technology]

[0002] Many aerosol-generating articles, i.e., smoking articles, in which tobacco is heated rather than burned have been proposed in the art. One goal of such heated aerosol-generating articles is to reduce known harmful smoke constituents of the type produced by the combustion and thermal decomposition of tobacco in conventional cigarettes.

[0003] Typically, in such heated aerosol-generating articles, the aerosol is generated by heat transfer to an aerosol-forming substrate or material physically separated from the heat source. During smoking, volatile compounds are released from the aerosol-forming substrate by heat transfer from the heat source and are carried along in the air drawn through the aerosol-generating article. As the released compounds cool, they condense to form the aerosol that is inhaled by the user.

[0004] Numerous prior art documents disclose aerosol generating devices for consuming or smoking heated aerosol-generating articles. For example, these devices include electrically heated aerosol generating devices in which the aerosol is generated by heat transfer from one or more electric heating elements of the aerosol generating device to an aerosol-forming substrate of the heated aerosol-generating article. One advantage of such electric smoking systems is that they allow users to selectively pause and resume smoking while significantly reducing sidestream smoke.

[0005] An example of an aerosol-generating article in the form of an electrically heated cigarette for use in an electrically operated aerosol-generating system is disclosed in US 2005 / 0172976 A1. The aerosol-generating article is configured to be inserted into a cigarette receiver of an aerosol-generating device of the aerosol-generating system. The aerosol-generating device comprises a power source that provides energy to a heater fixture including a plurality of electrically resistive heating elements that are arranged to slidably receive the aerosol-generating article so that the heating elements are positioned alongside the aerosol-generating article.

[0006] The system disclosed in US 2005 / 0172976 A1 utilizes an aerosol generating device with multiple external heating elements. Aerosol generating devices with internal heating elements are also known. In use, the internal heating element of such an aerosol generating device is inserted into the aerosol-forming substrate of the heated aerosol-generating article so that the internal heating element is in direct contact with the aerosol-forming substrate.

[0007] Direct contact between the internal heating element of the aerosol-generating device and the aerosol-forming substrate of the aerosol-generating article can provide an efficient means for heating the aerosol-forming substrate to form an inhalable aerosol. In such a configuration, heat from the internal heating element can be transferred almost instantaneously to at least a portion of the aerosol-forming substrate when the internal heating element is activated, which can promote rapid generation of the aerosol. Furthermore, the overall heating energy required to generate the aerosol can be lower than in aerosol-generating systems with external heater elements in which the aerosol-forming substrate is not in direct contact with the external heating element and in which initial heating of the aerosol-forming substrate occurs primarily by convection or radiation. When the internal heating element of the aerosol-generating device is in direct contact with the aerosol-forming substrate, initial heating of the portion of the aerosol-forming substrate in direct contact with the internal heating element is achieved primarily by conduction.

[0008] WO2013102614 discloses a system involving an aerosol-generating device with an internal heating element. In this system, the heating element is brought into contact with an aerosol-forming substrate, which undergoes a thermal cycle during which it heats and cools. Upon contact between the heating element and the aerosol-forming substrate, particles from the aerosol-forming substrate may adhere to the surface of the heating element. Furthermore, volatile compounds and aerosols generated by the heat from the heating element may become deposited on the surface of the heating element. Particles and compounds that adhere to the heating element may prevent the heating element from functioning optimally. These particles and compounds may also cause damage during use of the aerosol-generating device or impart an unpleasant or bitter taste to the user. For these reasons, it is desirable to periodically clean the heating element. The cleaning process may involve the use of cleaning tools such as brushes. Improper cleaning may damage or destroy the heating element. Furthermore, improper or careless insertion and removal of aerosol-generating items from the aerosol-generating device may also damage or destroy the heating element. Summary of the Invention

[0009] An aerosol-generating article is provided that includes a plurality of elements assembled in the form of a rod, the rod having a mouth end and a distal end upstream from the mouth end. The plurality of elements includes an aerosol-forming substrate located at or toward the distal end of the rod. An elongated susceptor is disposed substantially longitudinally within the rod and in thermal contact with the aerosol-forming substrate. The susceptor may have a thickness of 10 to 500 micrometers. In a preferred embodiment, the susceptor may have a thickness of 10 to 100 micrometers. The susceptor may be configured to dissipate energy between 1 watt and 8 watts, e.g., 1.5 watts to 6 watts, when coupled with a specific inductor. The term configured means that the elongated susceptor may be constructed of a specific material and have specific dimensions that allow for an energy dissipation between 1 watt and 8 watts when coupled with a specific conductor that generates a varying magnetic field of a known frequency and known field strength.

[0010] An aerosol generating system is also provided that includes an electrically operated aerosol generator having an inductor for generating an alternating or fluctuating electromagnetic field, and an aerosol-generating article having a susceptor as described and defined herein. The aerosol-generating article interfaces with the aerosol generator such that the fluctuating electromagnetic field generated by the inductor induces currents in the susceptor, causing it to heat. The electrically operated aerosol generator is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (H field strength) of 1 to 5 kiloamperes per meter (kA / m), preferably 2 to 3 kA / m, e.g., about 2.5 kA / m. The electrically operated aerosol generator is preferably capable of generating a fluctuating electromagnetic field having a frequency of 1 to 30 MHz, e.g., 1 to 10 MHz, e.g., 5 to 7 MHz.

[0011] The elongated susceptor is part of a consumable item and is therefore used only once. Thus, any residue that forms on the susceptor during heating does not cause problems for subsequent heating of the aerosol-generating article. The flavor of a series of aerosol-generating articles may be more consistent due to the fact that a fresh susceptor acts to heat each article. Furthermore, cleaning of the aerosol-generating device becomes less critical and can be accomplished without damage to the heating element. Furthermore, the absence of a heating element that must penetrate the aerosol-forming substrate makes insertion and removal of the aerosol-generating article into the aerosol-generating device less likely to cause inadvertent damage to either the article or the device. Thus, the overall aerosol-generating system is more robust.

[0012] As used herein, the term "aerosol-forming substrate" is used to describe a substrate that is capable of releasing, upon heating, a volatile compound capable of forming an aerosol. The aerosol generated from the aerosol-forming substrate of the aerosol-generating articles described herein may or may not be visible and may include vapor (e.g., fine particles of a substance that is normally liquid or solid at room temperature in a gaseous state) and liquid droplets of the gas and condensed vapor.

[0013] The terms "upstream" and "downstream" as used herein are used to describe the relative position of an element or portion of an element of an aerosol-generating article with respect to the direction that a user draws on the aerosol-generating article during their use.

[0014] The aerosol-generating article is in the form of a rod that includes two ends: a proximal end and a distal end, the oral end through which the aerosol exits the aerosol-generating article and is delivered to the user. In use, a user may pull on the oral end to inhale the aerosol generated by the aerosol-generating article. The oral end is downstream of the distal end. The distal end may also be referred to as the upstream end, and is upstream of the oral end.

[0015] The aerosol-generating article is preferably a smoking article that generates an aerosol that can be inhaled directly through a user's mouth into the user's lungs.Furthermore, the aerosol-generating article is preferably a smoking article that generates a nicotine-containing aerosol that can be inhaled directly through a user's mouth into the user's lungs.

[0016] As used herein, the term "aerosol-generating device" is used to describe a device that interacts with the aerosol-forming substrate of an aerosol-generating article to generate an aerosol. The aerosol-generating device is preferably a smoking device that interacts with the aerosol-forming substrate of an aerosol-generating article to generate an aerosol that is inhalable directly through the user's mouth into the user's lungs. The aerosol-generating device may also be a holder for a smoking article.

[0017] The term "longitudinal direction," when used herein in reference to an aerosol-generating article, is used to describe the direction between the mouth end and the distal end of the aerosol-generating article, and the term "lateral axis" is used to describe the direction perpendicular to the longitudinal axis.

[0018] The term "diameter," when used herein in relation to an aerosol-generating article, is used to describe the largest dimension of the aerosol-generating article along its transverse axis. The term "length," when used herein in relation to an aerosol-generating article, is used to describe the largest dimension of the aerosol-generating article along its longitudinal axis.

[0019] The term "susceptor," as used herein, refers to a material capable of converting electromagnetic energy into heat. When placed in a varying electromagnetic field, eddy currents induced within the susceptor cause the susceptor to heat. The elongated susceptor is positioned in thermal contact with the aerosol-forming substrate, so that the aerosol-forming substrate is heated by the susceptor.

[0020] The aerosol-generating article is designed to interface with an electrically operated aerosol-generating device that includes an induction heating source. The induction heating source, or inductor, generates a fluctuating electromagnetic field for heating a susceptor positioned within the fluctuating electromagnetic field. In use, the aerosol-generating article interfaces with the aerosol-generating device such that the susceptor is positioned within the fluctuating electromagnetic field generated by the inductor.

[0021] The susceptor has a length dimension that is greater than its width or thickness, e.g., greater than twice its width or thickness. Thus, the susceptor may be described as an elongated susceptor. The susceptor is substantially longitudinally aligned within the rod. This means that the length dimension of the elongated susceptor is aligned approximately parallel to the longitudinal axis of the rod, e.g., within ±10 degrees of parallel to the longitudinal axis of the rod. In a preferred embodiment, the elongated susceptor element may be located at a radially central position within the rod and extend along the longitudinal axis of the rod.

[0022] The susceptor is preferably in the form of a pin, rod, or blade. The susceptor preferably has a length of 5 mm to 15 mm, for example, 6 mm to 12 mm, or 8 mm to 10 mm. The susceptor preferably has a width of 1 mm to 5 mm and a thickness of 0.01 mm to 2 mm, for example, 0.5 mm to 2 mm. Preferred embodiments may have a thickness of 10 micrometers to 500 micrometers, with 10 to 100 micrometers being more preferred. If the susceptor has a constant cross-section (e.g., a circular cross-section), the preferred width or diameter may be 1 mm to 5 mm.

[0023] The susceptor can be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol-forming substrate. Preferred susceptors include metal or carbon. Preferred susceptors can include ferromagnetic materials, such as ferritic iron, or ferromagnetic steel or stainless steel. Suitable susceptors can be or include aluminum. Preferred susceptors can be formed from 400 series stainless steel, such as grade 410, grade 420, or grade 430 stainless steel. Different materials dissipate different amounts of energy when placed in an electromagnetic field of similar frequency and field strength. Thus, any of the susceptor parameters, such as material type, length, width, and thickness, can be varied to provide a desired power distribution within a known electromagnetic field.

[0024] Preferred susceptors can be heated to temperatures in excess of 250° C. Suitable susceptors may comprise a non-metallic core with a metal layer disposed thereon, such as a metal track formed on the surface of a ceramic core.

[0025] The susceptor may have a protective outer layer, such as a protective ceramic or glass layer that encapsulates the elongated susceptor material. The susceptor may include a protective coating formed of glass, ceramic, or an inert metal formed over a core containing the susceptor material.

[0026] The susceptor is arranged in thermal contact with the aerosol-forming substrate, such that as the temperature of the susceptor increases, the aerosol-forming substrate is heated and an aerosol is formed. Preferably, the susceptor is arranged in direct physical contact with the aerosol-forming substrate, for example, within the aerosol-forming substrate.

[0027] The aerosol-generating article may comprise a single elongated susceptor. Alternatively, the aerosol-generating article may comprise one or more elongated aerosol-generating articles.

[0028] The aerosol-forming substrate is preferably a solid aerosol-forming substrate. The aerosol-forming substrate may comprise solid and liquid components.

[0029] Preferably, the aerosol-forming substrate comprises nicotine. In some preferred embodiments, the aerosol-forming substrate comprises tobacco. For example, the aerosol-forming material may be a homogenized tobacco sheet.

[0030] Alternatively, or additionally, the aerosol-forming substrate may comprise a non-tobacco material comprising an aerosol-forming material, for example, the aerosol-forming material may be a sheet comprising a nicotine salt and an aerosol former.

[0031] Where the aerosol-forming substrate is a solid aerosol-forming substrate, the solid aerosol-forming substrate may comprise, for example, one or more of powder, granules, pellets, shreds, threads, strips or sheets including one or more of herb leaves, tobacco leaves, tobacco stems, expanded tobacco and homogenized tobacco.

[0032] Optionally, the solid aerosol-forming substrate may contain tobacco or non-tobacco volatile flavor compounds, which are released in response to heating of the solid aerosol-forming substrate. The solid aerosol-forming substrate may also contain one or more capsules, for example, containing additional tobacco or non-tobacco volatile flavor compounds, which may dissolve during heating of the solid aerosol-forming substrate.

[0033] Optionally, the solid aerosol-forming substrate may be provided on or embedded in a thermally stable carrier. The carrier may be in the form of a powder, granules, pellets, pieces, threads, strips, or a sheet. The solid aerosol-forming substrate may be deposited on the surface of the carrier in the form of, for example, a sheet, foam, gel, or slurry. The solid aerosol-forming substrate may be deposited on the entire surface of the carrier, or alternatively, may be deposited in a pattern to provide a non-uniform flavor delivery during use.

[0034] As used herein, the term "homogenized tobacco material" means a material formed by agglomerating particulate tobacco.

[0035] As used herein, the term "sheet" means a laminar element having a width and length that are substantially greater than its thickness.

[0036] As used herein, the term "collected" is used to describe a sheet that is rolled, folded, or otherwise compressed or contracted substantially transverse to the longitudinal axis of the aerosol-generating article.

[0037] In a preferred embodiment, the aerosol-forming substrate comprises an assemblage of textured sheets of homogenized tobacco material.

[0038] As used herein, the term "textured sheet" refers to a sheet that has been crimped, embossed, debossed, perforated, or otherwise modified. The aerosol-forming substrate may comprise an assemblage of a textured sheet of homogenized tobacco material that contains a plurality of spaced indentations, protrusions, perforations, or a combination thereof.

[0039] In a particularly preferred embodiment, the aerosol-forming substrate comprises an assemblage of crimped sheets of homogenized tobacco material.

[0040] The use of a textured sheet of homogenized tobacco material may advantageously facilitate consolidation of the homogenized tobacco material sheet to form the aerosol-forming substrate.

[0041] As used herein, the term "crimped sheet" refers to a sheet having a plurality of substantially parallel ridges or wrinkles. Preferably, the substantially parallel ridges or wrinkles extend along or parallel to the longitudinal axis of the aerosol-generating article when the aerosol-generating article is assembled. This conveniently facilitates assembly of the crimped sheet of homogenized tobacco material to form the aerosol-forming substrate. However, it is recognized that a crimped sheet of homogenized tobacco material for inclusion in an aerosol-generating article may alternatively or additionally have a plurality of substantially parallel ridges or wrinkles that are disposed at an acute or obtuse angle to the longitudinal axis of the aerosol-generating article when the aerosol-generating article is assembled.

[0042] The aerosol-forming substrate may be in the form of a plug comprising the aerosol-forming material surrounded by a paper or other wrapper. When the aerosol-forming substrate is in the form of a plug, the entire plug, including any wrapper, is considered to be the aerosol-forming substrate.

[0043] In a preferred embodiment, the aerosol-forming substrate comprises a plug containing an assemblage of homogenized sheets of tobacco material surrounded by a wrapper, or other aerosol-forming material, with the or each elongated susceptor preferably positioned within the plug in direct contact with the aerosol-forming material.

[0044] As used herein, the term "aerosol former" is used to describe any suitable known compound or mixture of compounds that, in use, facilitates the formation of an aerosol and is substantially resistant to thermal decomposition at the use temperature of the aerosol-generating article.

[0045] Suitable aerosol formers are well known in the art and include, but are not limited to, polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3-butanediol, and glycerin), esters of polyhydric alcohols (such as glycerol mono-, di-, or triacetate), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate and dimethyl tetradecanedioate).

[0046] Preferred aerosol formers are polyhydric alcohols or mixtures thereof such as propylene glycol, triethylene glycol, 1,3-butanediol, and most preferably glycerin.

[0047] The aerosol-forming substrate may comprise a single aerosol former, or alternatively, the aerosol-forming substrate may comprise a combination of two or more aerosol formers.

[0048] Preferably, the aerosol-forming substrate has an aerosol former content of greater than 5% on a dry weight basis.

[0049] The aerosol-forming substrate may have an aerosol former content of between about 5% and about 30% on a dry weight basis.

[0050] In a preferred embodiment, the aerosol-forming substrate has an aerosol former content of approximately 20% on a dry weight basis.

[0051] Aerosol-forming substrates comprising an aggregate of homogenized tobacco sheets for use in aerosol-generating articles may be manufactured by methods well known in the art, for example, as disclosed in WO 2012 / 164009 A2.

[0052] The outer diameter of the aerosol-forming substrate is preferably at least 5 mm. The outer diameter of the aerosol-forming substrate may be from about 5 mm to about 12 mm, for example from about 5 mm to about 10 mm, or from about 6 mm to about 8 mm. In a preferred embodiment, the aerosol-forming substrate has an outer diameter of 7.2 mm, + / - 10%.

[0053] The length of the aerosol-forming substrate may be about 5 mm to about 15 mm, for example about 8 mm to about 12 mm. In one embodiment, the aerosol-forming substrate may have a length of about 10 mm. In a preferred embodiment, the aerosol-forming substrate has a length of about 12 mm. The elongated susceptor preferably has approximately the same length as the aerosol-forming substrate.

[0054] The aerosol-forming substrate is preferably substantially cylindrical.

[0055] The support element may be located immediately downstream of the aerosol-forming substrate, or may be adjacent to the aerosol-forming substrate.

[0056] The support element may be formed from any suitable material or combination of materials. For example, the support element may be formed from one or more materials selected from the group consisting of cellulose acetate; cardboard; crimped paper, such as crimped heat-resistant paper or crimped parchment paper; and polymeric materials, such as low-density polyethylene (LDPE). In a preferred embodiment, the support element is formed from cellulose acetate.

[0057] The support element may comprise a hollow tubular element. In a preferred embodiment, the support element comprises a hollow cellulose acetate tube.

[0058] Preferably, the support element has an outer diameter approximately equal to the outer diameter of the aerosol-generating article.

[0059] The support element may have an outer diameter of between about 5 millimeters and about 12 millimeters, such as between about 5 millimeters and about 10 millimeters or between about 6 millimeters and about 8 millimeters. In a preferred embodiment, the support element has an outer diameter of 7.2 millimeters + / - 10%.

[0060] The support elements may have a length between approximately 5 mm and approximately 15 mm. In a preferred embodiment, the support elements have a length of approximately 8 mm.

[0061] The aerosol-cooling element can be located downstream of the aerosol-forming substrate, but for example the aerosol-cooling element can be located immediately downstream of the support element or adjacent to the support element.

[0062] The aerosol cooling element may be located between the support element and a mouthpiece located at the extreme downstream end of the aerosol-generating article.

[0063] The aerosol cooling element may have a total surface area of ​​between approximately 300 and 1000 square millimeters per millimeter of length. In a preferred embodiment, the aerosol cooling element has a total surface area of ​​approximately 500 square millimeters per millimeter of length.

[0064] The aerosol cooling element may alternatively be referred to as a heat exchanger.

[0065] The aerosol cooling element preferably has a low resistance to withdrawal, i.e., the aerosol cooling element preferably provides low resistance to the passage of air through the aerosol-generating article. Preferably, the aerosol cooling element does not substantially affect the resistance to withdrawal of the aerosol-generating article.

[0066] The aerosol cooling element may include a plurality of longitudinally extending channels. The plurality of longitudinally extending channels may be defined by a sheet of material that has been crimped, pleated, gathered, or folded in one or more processes to form the channels. The plurality of longitudinally extending channels may be defined by a single sheet that has been crimped, pleated, gathered, or folded in one or more processes to form the channels. Alternatively, the plurality of longitudinally extending channels may be defined by multiple sheets that have been crimped, pleated, gathered, or folded in one or more processes to form the channels.

[0067] In some embodiments, the aerosol cooling element may comprise an assembly of sheets of material selected from the group consisting of metal foil, polymeric material, and substantially non-porous paper or cardboard, hi some embodiments, the aerosol cooling element may comprise an assembly of sheets of material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), and aluminum foil.

[0068] In a preferred embodiment, the aerosol cooling element comprises an assembly of sheets of biodegradable material, for example, an assembly of sheets of non-porous paper or a biodegradable polymeric material such as polylactic acid or Mater-Bi® grades (a commercially available family of starch-based copolyesters).

[0069] In a particularly preferred embodiment, the aerosol cooling element comprises an assembly of sheets of polylactic acid.

[0070] The aerosol cooling element may be formed from an assembly of sheets of material having a specific surface area of ​​between approximately 10 and 100 square millimeters per milligram of weight. In some embodiments, the aerosol cooling element has a specific surface area of ​​approximately 35 mm 2 The material may be formed from an assembly of material sheets having a specific surface area of ​​1000 nm / mg.

[0071] The aerosol-generating article may include a mouthpiece located at the mouth end of the aerosol-generating article. The mouthpiece may be located immediately downstream of the aerosol cooling element or adjacent to the aerosol cooling element. The mouthpiece may include a filter. The filter may be formed from one or more suitable filtering materials. Many such filtering materials are well known in the art. In one embodiment, the mouthpiece may include a filter formed from cellulose acetate tow.

[0072] The mouthpiece preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article.

[0073] The mouthpiece may have an outer diameter of between about 5 millimeters and about 10 millimeters, for example between about 6 millimeters and about 8 millimeters. In a preferred embodiment, the mouthpiece has an outer diameter of 7.2 millimeters + / - 10%.

[0074] The mouthpiece may have a length between approximately 5 millimeters and approximately 20 millimeters. In a preferred embodiment, the mouthpiece has a length of approximately 14 millimeters.

[0075] The mouthpiece may have a length between approximately 5 millimeters and approximately 14 millimeters. In a preferred embodiment, the mouthpiece has a length of approximately 7 millimeters.

[0076] The elements of the aerosol-forming article, such as the aerosol-forming substrate and any other elements of the aerosol-generating article (such as the support element, the aerosol cooling element, and the mouthpiece), are surrounded by an outer wrapper. The outer wrapper may be made of any suitable material or combination of materials. Preferably, the outer wrapper is cigarette paper.

[0077] The aerosol-generating article may have an outer diameter of between about 5 millimeters and about 12 millimeters, for example between about 6 millimeters and about 8 millimeters. In a preferred embodiment, the aerosol-generating article has an outer diameter of 7.2 millimeters + / - 10%.

[0078] The aerosol-generating article may have a total length of between about 30 mm and about 100 mm. In a preferred embodiment, the total length of the aerosol-generating article is between 40 mm and 50 mm, for example about 45 mm.

[0079] The aerosol generating device of the aerosol generating system may include a housing, a cavity for receiving an aerosol-generating article, an inductor arranged to generate a varying electromagnetic field within the cavity, a power supply connected to the inductor, and a control element configured to control the power supply from the power source to the inductor.

[0080] The inductor may comprise one or more coils that generate a varying electromagnetic field. The coil(s) may surround the cavity.

[0081] Preferably the device is capable of generating a fluctuating electromagnetic field in the range of 1 to 30 MHz, such as 2 to 10 MHz, for example 5 to 7 MHz.

[0082] Preferably, the device is capable of generating a varying electromagnetic field with a field strength (H field) of 1-5 kA / m, such as 2-3 kA / m, for example about 2.5 kA / m.

[0083] Preferably, the aerosol generating device is a portable or handheld aerosol generating device that a user can easily hold between the fingers of a single hand.

[0084] The aerosol generating device may be substantially cylindrical in shape.

[0085] The aerosol generating device may have a length between about 70 millimeters and about 120 millimeters.

[0086] The power supply may be any suitable power supply, for example, a DC voltage source such as a battery. In one embodiment, the power supply is a lithium ion battery. Alternatively, the power supply may be a nickel metal hydride battery, a nickel cadmium battery, or a lithium-based battery, such as a lithium cobalt, lithium iron phosphate, lithium titanate, or lithium polymer battery.

[0087] The control element may be a simple switch, or it may be an electrical circuit and may include one or more microprocessors or microcontrollers.

[0088] The aerosol-generating system may comprise an aerosol-generating device and one or more aerosol-generating articles configured to be received within a cavity of the aerosol-generating device such that a susceptor located within the aerosol-generating article is positioned within the varying electromagnetic field generated by the inductor. A method of using the aerosol-generating articles as described above may include positioning the article relative to an electrically operated aerosol-generating device such that an elongated susceptor of the article is within the varying electromagnetic field generated by the device, controlling the magnetic field strength of the varying electromagnetic field so that the power dispersed within the elongated susceptor during a first time period is between 5 and 6 watts, and varying the magnetic field strength of the varying electromagnetic field so that the power dispersed within the elongated susceptor during a second time period is between 1.5 and 2 watts.

[0089] During a first period, the susceptor rapidly heats the aerosol-forming substrate to a working temperature for delivering the aerosol. The first period can last, for example, 1 to 10 seconds. During a second period, the susceptor maintains the aerosol-forming substrate at its working temperature. By reducing the power dissipated by the susceptor, overheating of the aerosol-forming substrate can be prevented, improving the battery life of the device.

[0090] The electrically operated aerosol generating device may be any of the devices described herein. The frequency of the alternating electromagnetic field is preferably maintained at 1-30 MHz, for example 5-7 MHz.

[0091] A method of manufacturing an aerosol-generating article as described or defined herein may comprise assembling a plurality of elements in the form of a rod having a mouth end and a distal end upstream from the mouth end, the plurality of elements including an aerosol-forming substrate and a susceptor having elongated susceptor elements arranged substantially longitudinally within the rod, the susceptor being in thermal contact with the aerosol-forming substrate, preferably in direct contact with the aerosol-forming substrate.

[0092] Advantageously, the aerosol-forming substrate can be produced by assembling at least one sheet of aerosol-forming material and surrounding the assembly of sheets with a wrapper. A suitable method for producing such an aerosol-forming substrate for a heated aerosol-generating article is disclosed in WO2012164009. The sheet of aerosol-forming material can be a sheet of homogenized tobacco. Alternatively, the sheet of aerosol-forming material can be a sheet containing non-tobacco material, such as a nicotine salt and an aerosol former.

[0093] The, or each, elongate susceptor may be inserted into the aerosol-forming substrate before the aerosol-forming substrate is assembled with other elements to form the aerosol-generating article. Alternatively, the aerosol-forming substrate may be assembled with other elements before the susceptor is inserted into the aerosol-forming substrate.

[0094] Also, features described with respect to one aspect or embodiment may be applicable to other aspects and embodiments.Specific embodiments will now be described with reference to the figures. [Brief explanation of the drawings]

[0095] [Figure 1] FIG. 1 is a schematic cross-sectional view of a specific embodiment of an aerosol-generating article. [Figure 2] FIG. 2 is a schematic cross-sectional view of a specific embodiment of an electrically operated aerosol generating device for use with the aerosol-generating article illustrated in FIG. [Figure 3] 3 is a schematic cross-sectional view of the aerosol-generating article of FIG. 1 in conjunction with the electrically operated aerosol-generating device of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0096] FIG. 1 illustrates an aerosol-generating article 10 according to a preferred embodiment. The aerosol-generating article 10 includes four coaxially aligned elements: an aerosol-forming substrate 20, a support element 30, an aerosol-cooling element 40, and a mouthpiece 50. Each of these four elements is substantially cylindrical and has substantially the same diameter. These four elements are arranged in series and surrounded by an outer wrapper 60 to form a cylindrical rod. A blade-shaped susceptor 25 is located within and in contact with the aerosol-forming substrate. The susceptor 25 has a length approximately equal to the length of the aerosol-forming substrate and is positioned along the radial center axis of the aerosol-forming substrate.

[0097] The susceptor 25 is a ferritic iron material having a length of 10 mm, a width of 3 mm and a thickness of 1 mm. One or both ends of the susceptor may be sharpened or pointed to facilitate insertion into the aerosol-forming substrate.

[0098] The aerosol-generating article 10 has a proximal or oral end 70 that a user inserts into their mouth during use, and a distal end 80 that is located at the opposite end of the aerosol-generating article 10 from the oral end 70. The assembled aerosol-generating article 10 has a total length of about 45 mm and a diameter of about 7.2 mm.

[0099] In use, air is drawn through the aerosol-generating article by a user from the distal end 80 to the oral end 70. The distal end 80 of the aerosol-generating article may also be described as the upstream end of the aerosol-generating article 10, and the oral end 70 of the aerosol-generating article 10 may also be described as the downstream end of the aerosol-generating article 10. Elements of the aerosol-generating article 10 located between the oral end 70 and the distal end 80 may be described as being upstream of the oral end 70, or alternatively, downstream of the distal end 80.

[0100] The aerosol-forming substrate 20 is located at the extreme distal or upstream end 80 of the aerosol-generating article 10. In the embodiment illustrated in Figure 1, the aerosol-forming substrate 20 comprises an assembly of a crimped, homogenized tobacco material sheet surrounded by a wrapper. The crimped sheet of homogenized tobacco material contains glycerin as an aerosol former.

[0101] The support element 30 is located directly downstream of and adjacent to the aerosol-forming substrate 20. In the embodiment shown in FIG. 1 , the support element is a hollow cellulose acetate tube. The support element 30 positions the aerosol-forming substrate 20 at the extreme distal end 80 of the aerosol-generating article 10 so that it can be penetrated by the susceptor 25 during manufacture of the aerosol-generating article 10. In this manner, the support element 30 helps prevent the aerosol-forming substrate 20 from being pushed downstream into the aerosol-generating article 10 toward the aerosol-cooling element 40 when the susceptor 25 is inserted into the aerosol-forming substrate 20. The support element 30 also serves as a spacer that spaces the aerosol-forming substrate 20 from the aerosol-forming substrate 20 and the aerosol-cooling element 40 of the aerosol-generating article 10.

[0102] The aerosol cooling element 40 is located directly downstream of and adjacent to the support element 30. In use, volatile material emitted from the aerosol-forming substrate 20 passes along the aerosol cooling element 40 toward the mouth end 70 of the aerosol-generating article 10. The volatile material may cool within the aerosol cooling element 40 to form an aerosol that is inhaled by the user. In the embodiment illustrated in FIG. 1 , the aerosol cooling element comprises an assembly of crimped sheets of polylactic acid surrounded by a wrapper 90. The assembly of crimped sheets of polylactic acid defines a plurality of longitudinal channels extending along the length of the aerosol cooling element 40.

[0103] Mouthpiece 50 is located directly downstream of and adjacent to aerosol cooling element 40. In the embodiment shown in Figure 1, mouthpiece 50 includes a conventional cellulose acetate tow filter with low filtration efficiency.

[0104] To assemble the aerosol-generating article 10, the four cylindrical elements are aligned and tightly wrapped within an outer wrapper 60. In the embodiment illustrated in Figure 1, the outer wrapper is conventional cigarette paper. A susceptor 25 is then inserted into the distal end 80 of the assembly so as to penetrate the aerosol-forming substrate 20 to form the complete aerosol-generating article 10.

[0105] As an alternative method of assembly, the susceptor 25 may be inserted into the aerosol-forming substrate 20 before assembling the elements to form the rod.

[0106] The aerosol-generating article 10 illustrated in FIG. 1 is designed to operate in conjunction with an electrically operated aerosol-generating device that includes an induction coil (ie, an inductor) for smoking or consumption by a user.

[0107] A schematic cross-sectional view of an electrically operated aerosol generating device 200 is shown in Figure 2. The aerosol generating device 200 includes an inductor 210. As shown in Figure 2, the inductor 210 is located adjacent to a distal portion 231 of a substrate-receiving chamber 230 of the aerosol generating device 200. In use, a user inserts the aerosol-generating article 10 into the substrate-receiving chamber 230 of the aerosol generating article 10 so that the aerosol-forming substrate 20 of the aerosol-generating article 10 is located adjacent to the inductor 210.

[0108] The aerosol generating device 200 includes a battery 250 and electronic circuitry 260 that activates the inductor 210. Such activation may be manual or may occur automatically in response to a user withdrawing an aerosol-generating article 10 that is inserted into the substrate-receiving chamber 230 of the aerosol generating device 200.

[0109] In operation, a high-frequency alternating current is passed through a wound coil forming part of the inductor 210, causing the inductor 210 to generate a varying electromagnetic field within the distal portion 231 of the substrate-receiving cavity 230 of the device. The frequency of the electromagnetic field varies between 1 and 30 MHz, preferably between 2 and 10 MHz, e.g., between 5 and 7 MHz. When the aerosol-generating article 10 is properly positioned within the substrate-receiving cavity 230, the susceptor 25 of the article 10 is positioned within this varying electromagnetic field. The varying electromagnetic field generates eddy currents within the susceptor, which then heats up. The heated susceptor heats the aerosol-forming substrate 20 of the aerosol-generating article 10 to a temperature sufficient to form an aerosol, e.g., about 340°C. The aerosol is drawn downstream through the aerosol-generating article 10 and is inhaled by the user. Figure 3 illustrates an aerosol-generating article in conjunction with an electrically operated aerosol generating device.

[0110] The specific embodiment described in connection with FIG. 1 includes an aerosol-forming substrate formed from homogenized tobacco. In other embodiments, the aerosol-forming substrate may be formed from a different material. For example, a second specific embodiment of an aerosol-generating article has the same elements as those described above in connection with the embodiment of FIG. 1, except that the aerosol-forming substrate 20 is formed from a non-tobacco sheet of cigarette paper soaked in a liquid formulation containing nicotine pyruvate, glycerin, and water. The cigarette paper absorbs the liquid formulation, so that the non-tobacco sheet contains nicotine pyruvate, glycerin, and water. The glycerin to nicotine ratio is 5:1. During use, the aerosol-forming substrate 20 is heated to a temperature of approximately 220 degrees Celsius. At this temperature, an aerosol containing nicotine pyruvate, glycerin, and water is emitted, which can be drawn into the user's mouth through the filter 50. It is noted that the substrate 20 is heated to a temperature significantly lower than the temperature required to emit an aerosol from a tobacco substrate.

[0111] In one particular embodiment of the aerosol-generating article, the article is as described above in connection with FIG. 1 , except that the susceptor has a length of 12 mm, a width of 4 mm, and a thickness of 12 micrometers. The susceptor is formed of grade 430 stainless steel. The device can be consumed using an electrically operated aerosol-generating device, as described above. In a preferred example, the device generates a varying electromagnetic field having a frequency of about 7 MHz and a magnetic field strength (H field) of about 2.5 kA / m. In a preferred example, the magnetic field strength varies during consumption of the article, varying the power dissipated by the susceptor and therefore the energy supplied to the aerosol-forming substrate during consumption of the article. This may allow the aerosol-forming substrate to rapidly reach a use temperature, e.g., about 340°C, and then be efficiently maintained at or near that temperature by supplying a smaller amount of energy.

[0112] The above exemplary embodiments are not intended to limit the scope of the claims, and other embodiments consistent with the above exemplary embodiments will be apparent to those skilled in the art.

Claims

1. 1. An aerosol-generating article (10) comprising a plurality of elements assembled in the form of a rod having an oral end (70) and a distal end (80) upstream from the oral end, the plurality of elements including an aerosol-forming substrate (20) located at or towards the distal end of the rod, wherein an elongated susceptor (25) having a thickness of 10 to 100 micrometers is disposed substantially longitudinally within the rod and in thermal contact with the aerosol-forming substrate (20).

2. 2. The aerosol-generating article of claim 1, wherein the elongated susceptor (25) is located within the aerosol-forming substrate (20).

3. 3. The aerosol-generating article of claim 2, wherein the elongated susceptor (25) is positioned radially centrally within the rod and extends along the longitudinal axis of the rod.

4. An aerosol-generating article according to any one of claims 1 to 3, wherein the elongated susceptor (25) is in the shape of a pin, a rod or a blade.

5. An aerosol-generating article according to any one of claims 1 to 4, wherein the elongated susceptor (25) comprises a metal, such as ferritic iron, or stainless steel, preferably grade 410, 420 or 430 stainless steel.

6. 6. The aerosol-generating article of claim 5, wherein the elongated susceptor (25) comprises a non-metallic core with a metallic layer disposed thereon.

7. 7. An aerosol-generating article according to any one of claims 1 to 6, wherein the elongated susceptor (25) comprises a protective outer layer, for example a protective ceramic layer or a protective glass layer, sealing the elongated susceptor.

8. An aerosol-generating article according to any one of claims 1 to 7, wherein the aerosol-forming substrate (20) is in the form of a rod comprising an assembly of sheets of aerosol-forming material.

9. 9. The aerosol-generating article of claim 8, wherein the aerosol-forming material is a homogenized tobacco sheet.

10. 9. The aerosol-generating article of claim 8, wherein the aerosol-forming material is a sheet comprising a nicotine salt (such as nicotine pyruvate) and an aerosol former.

11. An aerosol-generating article according to any one of claims 1 to 10, comprising one or more elongated susceptors (25).

12. 12. An aerosol generation system comprising an electrically operated aerosol generator (200) having an inductor (210) for generating an alternating electromagnetic field and an aerosol-generating article (10) as defined in any one of claims 1 to 11, wherein the aerosol-generating article (10) interfaces with the aerosol-generating device (200) such that the alternating magnetic field generated by the inductor (210) induces currents in the susceptor (25) and heats the susceptor (25).

13. 13. The system of claim 12, wherein the electrically operated aerosol-generating device is capable of inducing a varying magnetic field having a frequency of 1 to 30 MHz and an H field strength of 1 to 5 kiloamperes per meter (kA / m), and wherein the aerosol-generating article comprises an elongated susceptor capable of dissipating 1.5 to 8 watts of power when positioned within the varying magnetic field.

14. A method of using an aerosol-generating article as defined in any one of claims 1 to 11, comprising the steps of: positioning the article relative to an electrically operated aerosol generating device such that the elongated susceptor of the article is within a varying electromagnetic field generated by the device; controlling the magnetic field strength of the varying electromagnetic field so that the power dissipated by the elongated susceptor during a first period is between 5 and 6 watts; varying the magnetic field strength of the varying electromagnetic field so that the power dissipated by the elongated susceptor during a second period is between 1.5 and 2 watts.

15. 15. The method of claim 14, wherein the frequency of the varying electromagnetic field is between 1 and 30 MHz, for example between 5 and 7 MHz.

16. 12. A method for manufacturing an aerosol-generating article (10) according to any one of claims 1 to 11, comprising assembling a plurality of elements into the form of a rod having a mouth end (70) and a distal end (80) upstream of said mouth end, said plurality of elements including an aerosol-forming substrate (20) and an elongated susceptor (25) disposed substantially longitudinally within said rod and in thermal contact with said aerosol-forming substrate.

17. 17. The method of claim 16, wherein the aerosol-forming substrate (20) is produced by assembling at least one sheet of aerosol-forming material and surrounding the assembly of sheets with a wrapper.

18. 18. The method of claim 16 or 17, comprising inserting the elongated susceptor (25) into the aerosol-forming substrate (20) such that the elongated susceptor is positioned substantially longitudinally within the assembled aerosol-generating article (10).

19. 19. The method according to claim 18, wherein the elongated susceptor (25) is inserted into the aerosol-forming substrate (20) before the plurality of elements are assembled into the form of a rod, or the elongated susceptor is inserted into the aerosol-forming substrate after the plurality of elements are assembled into the form of a rod.

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