Aerosol-generating article comprising an internal susceptor

Abstract

To provide an aerosol-generating article including an aerosol-forming base substrate used to generate inhalable aerosols when heated.SOLUTION: An aerosol-generating article (10) comprises a plurality of elements assembled in a shape of a rod having a mouth-side end (70) and a distal end (80) located upstream from the mouth-side end. The plurality of elements include an aerosol-forming base substrate (20) located at or toward the distal end of the rod. An elongated susceptor (25) is arranged in a substantial longitudinal direction inside the rod and in thermal contact with the aerosol-forming base substrate (20). Using an electrically operable aerosol-generating device having an inductor, the susceptor allows the article to be consumed.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

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

[0003] Typically, in such heated aerosol-generating articles, the aerosol is generated by heat transfer from a heat source to an aerosol-forming substrate or material physically remote 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 together in the air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol inhaled by the user.

[0004] A number of prior art documents disclose aerosol-generating devices for consuming or smoking heated aerosol-generating articles. For example, such devices include electrically heated aerosol-generating devices in which the aerosol is generated by heat transfer from one or more electrical heating elements of the aerosol-generating device to the aerosol-forming substrate of the heated aerosol-generating article. One advantage of such an electric smoking system is that it can significantly reduce sidestream smoke while allowing the user to selectively pause and resume smoking.

[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 receptacle of an aerosol-generating device of the aerosol-generating system. The aerosol-generating device comprises a power source that supplies energy to a heater fixture including a plurality of electrically resistive heating elements arranged to receive the aerosol-generating article in a slidable manner such that a heating element is positioned along the aerosol-generating article.

[0006] The system disclosed in US 2005 / 0172976 A1 utilizes an aerosol-generating device with a plurality of 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 a heated aerosol-generating article such that the internal heating element is in direct contact with the aerosol-forming substrate.

[0007] The 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 of heating the aerosol-forming substrate to form an inhalable aerosol. In such a configuration, heat from the internal heating element can be transmitted almost instantaneously to at least a portion of the aerosol-forming substrate when the internal heating element is activated, thereby facilitating rapid generation of the aerosol. Further, the overall heating energy required to generate the aerosol can be lower than in an aerosol-generating system having an external heater element where the aerosol-forming substrate is not in direct contact with the external heating element and where initial heating of the aerosol-forming substrate occurs mainly 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 mainly by conduction.

[0008] A system involving an aerosol generating device having an internal heating element is disclosed in WO2013102614. In this system, the heating element is brought into contact with the aerosol forming substrate, and the heating element circulates through a thermal cycle during which heating and cooling occur. When the heating element contacts the aerosol forming substrate, the particles of the aerosol forming substrate can adhere to the surface of the heating element. Further, volatile compounds and aerosols generated by the heat from the heating element can come to adhere on the surface of the heating element. The particles and compounds adhering and attaching to the heating element can prevent the heating element from functioning in an optimal manner. These particles and compounds can also cause damage during the use of the aerosol generating device or give the user an unpleasant or bitter flavor. For these reasons, it is desirable to clean the heating element regularly. The cleaning process may involve the use of a cleaning tool such as a brush. If the cleaning is inappropriate, the heating element may be damaged or broken. Further, inappropriate or careless insertion and removal of aerosol generating articles into the aerosol generating device can also damage or break 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-side end and a distal end upstream from the mouth-side end. The plurality of elements includes an aerosol forming substrate located at or towards the distal end of the rod. An elongated susceptor is disposed substantially longitudinally within the rod and is in thermal contact with the aerosol forming substrate. The susceptor can have a thickness of 10 to 500 micrometers. In a preferred embodiment, the susceptor can have a thickness of 10 to 100 micrometers. The susceptor can be configured to have a dissipated energy of 1 watt to 8 watts, for example 1.5 watts to 6 watts, when used in combination with a specific inductor. The term configured means that the elongated susceptor can be composed of a specific material and can have specific dimensions that allow for a dissipated energy of 1 watt to 8 watts when used in combination with a specific conductor that generates a fluctuating magnetic field of a well-known frequency and a well-known magnetic field strength.

[0010] An aerosol generating system is also provided that includes an electrically operated aerosol generating device having an inductor for generating an alternating electromagnetic field or a varying electromagnetic field, and an aerosol generating article comprising a susceptor as described and defined herein. The aerosol generating article is interlocked with the aerosol generating device such that a varying electromagnetic field generated by the inductor induces a current in the susceptor to heat the susceptor. The electrically operated aerosol generating device preferably has the ability to generate a varying electromagnetic field having a magnetic field strength (intensity of the H-field) of 1 to 5 kiloamperes per meter (kA / m), preferably 2 to 3 kA / m, for example about 2.5 kA / m. The electrically operated aerosol generating device preferably has the ability to generate a varying electromagnetic field having a frequency of 1 to 30 MHz, for example 1 to 10 MHz, for example 5 to 7 MHz.

[0011] The elongated susceptor is a consumable part and is therefore used only once. Thus, any residue formed on the susceptor during heating will not cause problems for subsequent heating of the aerosol generating article. The flavor of a series of aerosol generating articles can be more consistent due to the fact that a fresh susceptor acts to heat each article. Further, the cleaning of the aerosol generating device becomes less important and can be achieved without damaging the heating element. Further, the absence of a heating element that needs to penetrate the aerosol forming substrate reduces the likelihood that the insertion and removal of the aerosol generating article into the aerosol generating device will cause inadvertent damage to either the article or the device. Thus, the overall aerosol generating system is more robust.

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

[0013] When the terms "upstream" and "downstream" are used in this specification, they are used to describe the relative position of an element or a part of an element of an aerosol-generating article with respect to the direction in which the 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, namely the mouth-side end, i.e., the proximal end or the distal end, through which the aerosol exits the aerosol-generating article and is delivered to the user. In use, the user may draw on the mouth-side end to inhale the aerosol generated by the aerosol-generating article. The mouth-side end is downstream of the distal end. Also, the distal end may be referred to as the upstream end and is upstream of the mouth-side end.

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

[0016] The term "aerosol-generating device" as used in this specification 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 the aerosol-generating article to generate an aerosol that can be directly inhaled into the user's lungs through the user's mouth. The aerosol-generating device may also be a holder for a smoking article.

[0017] When the term "longitudinal direction" is used in this specification in relation to an aerosol-generating article, it is used to describe the direction between the mouth-side end and the distal end of the aerosol-generating article, and the term "transverse axis" is used to describe the direction perpendicular to the longitudinal direction.

[0018] When the term "diameter" is used in this specification in relation to an aerosol-generating article, it is used to describe the maximum dimension in the lateral axis direction of the aerosol-generating article. When the term "length" is used in this specification in relation to an aerosol-generating article, it is used to describe the maximum dimension in the major axis direction of the aerosol-generating article.

[0019] When the term " susceptor " is used in this specification, it means a material capable of converting electromagnetic energy into heat. When located within a varying electromagnetic field, eddy currents induced within the susceptor cause heating of the susceptor. Since the elongated susceptor is in a position in thermal contact with the aerosol-forming substrate, the aerosol-forming substrate is heated by the susceptor.

[0020] The aerosol-generating article is designed to operate in conjunction with an electrically-operated aerosol-generating device having an induction heating source. The induction heating source, or inductor, generates a varying electromagnetic field for heating a susceptor located within the varying electromagnetic field. In use, the aerosol-generating article operates in conjunction with the aerosol-generating device such that the susceptor is located within the varying electromagnetic field generated by the inductor.

[0021] The susceptor has a length dimension that is greater than its width dimension or its thickness dimension, for example greater than twice its width dimension or its thickness dimension. Thus, the susceptor can be depicted as an elongated susceptor. The susceptor is arranged substantially in the major axis direction within the rod. This means that the length dimension of the elongated susceptor is aligned substantially parallel to the major axis direction of the rod, for example within ±10 degrees parallel to the major axis direction 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 major axis direction of the rod.

[0022] The susceptor is preferably in the form of pins, rods, or blades. The susceptor preferably has a length of 5 mm to 15 mm, such as 6 mm to 12 mm, or 8 mm to 10 mm. The susceptor preferably has a width of 1 mm to 5 mm and can have a thickness of 0.01 mm to 2 mm, such as 0.5 mm to 2 mm. Preferred embodiments can have a thickness of 10 micrometers to 500 micrometers, but more preferably 10 to 100 micrometers. When the susceptor has a constant cross-section (e.g., circular cross-section), the preferred width or diameter can 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 contain metal or carbon. Preferred susceptors can include ferromagnetic materials such as ferrite iron, or ferromagnetic steel or stainless steel. Suitable susceptors can be or include aluminum. Preferred susceptors can be formed from 400 series stainless steels such as grade 410, or grade 420, or grade 430 stainless steel. Different materials dissipate different amounts of energy when placed in an electromagnetic field with similar values of frequency and magnetic field strength. Thus, any of the susceptor parameters such as material type, length, width, and thickness can be varied to provide the desired power dissipation in a known electromagnetic field.

[0024] Preferred susceptors can be heated to temperatures above 250 °C. Suitable susceptors can 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 can have a protective outer layer, such as a protective ceramic layer or a protective glass layer that encapsulates the elongate susceptor material. The susceptor can comprise a protective coating formed of glass, ceramic, or an inert metal formed on a core containing the susceptor material.

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

[0027] The aerosol-generating article can comprise a single elongate susceptor. Alternatively, the aerosol-generating article can comprise one or more elongate 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] The aerosol-forming substrate preferably contains nicotine. In some preferred embodiments, the aerosol-forming substrate contains tobacco. For example, the aerosol-forming material can be a homogenized tobacco sheet.

[0030] Alternatively, or in addition, the aerosol-forming substrate may contain a non-tobacco containing an aerosol-forming material. For example, the aerosol-forming material can be a sheet containing a nicotine salt and an aerosol-forming body.

[0031] When the aerosol-forming substrate is a solid aerosol-forming substrate, the solid aerosol-forming substrate can comprise one or more of herb leaves, tobacco leaves, tobacco stems, expanded tobacco and homogenized tobacco, for example, it can comprise one or more of powder, granules, pellets, fragments, threads, flakes or sheets.

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

[0033] Optionally, the solid aerosol-forming substrate may be provided on or embedded within a thermally stable carrier. The carrier may take the form of a powder, granule, pellet, fragment, yarn, flake or sheet. The solid aerosol-forming substrate may be deposited on the surface of the carrier, for example, in the form of a sheet, foam, gel or slurry. The solid aerosol-forming substrate may be deposited over the entire surface of the carrier or, alternatively, may be deposited in a pattern to provide non-uniform flavor delivery during use.

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

[0035] As used herein, the term "sheet" means a thin, layer-like element having a width and length substantially greater than its thickness.

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

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

[0038] As used herein, the term "textured sheet" means a sheet that has been crimped, embossed, debossed, perforated, or otherwise deformed. The aerosol-forming substrate may comprise an assembly of textured sheets of homogenized tobacco material that includes a plurality of spaced dimples, protrusions, perforations, or combinations thereof.

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

[0040] The use of a textured sheet of homogenized tobacco material may conveniently facilitate the aggregation of the homogenized tobacco material sheets to form an aerosol-forming substrate.

[0041] As used herein, the term "crimped sheet" means a sheet having a plurality of substantially parallel ridges or wrinkles. When the aerosol-generating article is assembled, the substantially parallel ridges or wrinkles preferably extend along or parallel to the longitudinal axis of the aerosol-generating article. This conveniently facilitates the assembly of a collection of crimped sheets of homogenized tobacco material to form an aerosol-forming substrate. However, it is recognized that the crimped sheets of homogenized tobacco material for inclusion in an aerosol-generating article may alternatively or additionally have a plurality of substantially parallel ridges or wrinkles 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 containing an aerosol-forming material surrounded by 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 an assembly of homogenized tobacco material sheets surrounded by a wrapper, or a plug containing other aerosol-forming material. The elongated susceptor or each elongated susceptor is preferably disposed in direct contact with the aerosol-forming material within the plug.

[0044] As used herein, the term "aerosol former" is used to describe any suitable well-known compound or mixture of compounds that, in use, facilitates the formation of an aerosol and is substantially resistant to thermal decomposition at the temperature of use 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. Alternatively, the aerosol - forming substrate may comprise a combination of two or more aerosol formers.

[0048] The aerosol - forming substrate preferably has an aerosol - former content of more than 5% on a dry - mass basis.

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

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

[0051] An aerosol - forming substrate comprising an assembly of homogenized tobacco sheets for use in an aerosol - generating article can be manufactured by methods well known in the art, such as those disclosed in, for example, 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 approximately 5 mm to approximately 12 mm, for example, from approximately 5 mm to approximately 10 mm, or from approximately 6 mm to approximately 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 from approximately 5 mm to approximately 15 mm, for example, from about 8 mm to about 12 mm. In one embodiment, the aerosol-forming substrate may have a length of approximately 10 mm. In a preferred embodiment, the aerosol-forming substrate has a length of approximately 12 mm. The elongated susceptor is preferably approximately the same length as the aerosol-forming substrate.

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

[0055] The support element can be located immediately downstream of the aerosol-forming substrate and can 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; crumpled paper such as crumpled heat-resistant paper or crumpled sulfuric acid 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 include a hollow tubular element. In a preferred embodiment, the support element includes a hollow cellulose acetate tube.

[0058] The support element preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol-generating article.

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

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

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

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

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

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

[0065] The aerosol cooling element preferably has a low draw resistance. That is, the aerosol cooling element preferably provides low resistance to the passage of air through the aerosol-generating article. It is preferred that the aerosol cooling element does not substantially affect the draw resistance of the aerosol-generating article.

[0066] The aerosol cooling element may include a plurality of paths extending in the longitudinal direction. The plurality of paths extending in the longitudinal direction may be defined by a sheet material in which one or more processes such as curling, pleating, gathering, and folding are performed to form the paths. The plurality of paths extending in the longitudinal direction may be defined by a single sheet in which one or more processes such as curling, pleating, gathering, and folding are performed to form the plurality of paths. Alternatively, the plurality of paths extending in the longitudinal direction may be defined by a plurality of sheets in which one or more processes such as curling, pleating, gathering, and folding are performed to form the plurality of paths.

[0067] In some embodiments, the aerosol cooling element may include an assembly of sheet materials selected from the group consisting of metal foils, polymeric materials, and substantially non-porous paper or cardboard. In some embodiments, the aerosol cooling element may include an assembly of sheet materials 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 includes an assembly of biodegradable sheet materials. For example, an assembly of sheets of non-porous paper or an assembly of biodegradable polymer sheet materials such as polylactic acid or a grade of Mater-Bi® (a commercial family of starch-based copolyesters).

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

[0070] The aerosol cooling element may be formed from an assembly of sheet materials having a specific surface area of approximately 10 to 100 square millimeters per milligram by weight. In some embodiments, the aerosol cooling element may have a specific surface area of approximately 35 mm 2 / mg and may be formed from an assembly of sheet materials.

[0071] The aerosol-generating article may include a mouthpiece located at the mouth-side end of the aerosol-generating article. The mouthpiece can 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 filter materials. Many such filter 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 that is approximately equal to the outer diameter of the aerosol-generating article.

[0073] The mouthpiece may have an outer diameter between approximately 5 millimeters and approximately 10 millimeters, for example between approximately 6 millimeters and approximately 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] Elements of the aerosol-forming article, such as the aerosol-forming substrate and any other optional elements of the aerosol-generating article (such as a support element, an aerosol cooling element, and a mouthpiece), are surrounded by an outer wrapper. The outer wrapper may be formed from any suitable material or combination of materials. The outer wrapper is preferably cigarette paper.

[0077] The aerosol-generating article may have an outer diameter between approximately 5 millimeters and approximately 12 millimeters, for example between approximately 6 millimeters and approximately 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 an overall length between approximately 30 millimeters and approximately 100 millimeters. In a preferred embodiment, the total length of the aerosol-generating article is 40 mm to 50 mm, for example approximately 45 millimeters.

[0079] The aerosol generator of the aerosol generation system may comprise a housing, a recess for receiving the aerosol-generating article, an inductor arranged to generate a varying electromagnetic field within the recess, 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 recess.

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

[0082] Preferably, the device is capable of generating a varying electromagnetic field having a magnetic field strength (H-field) in the range of 1 to 5 kA / m, for example 2 to 3 kA / m, for example approximately 2.5 kA / m.

[0083] Preferably, the aerosol generator is a portable or hand-held aerosol generator that is easy for a user to hold between the fingers of a single hand.

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

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

[0086] The power supply may be any suitable power supply, such as a DC voltage source like 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. Alternatively, the control element may be an electrical circuit and may include one or more microprocessors or microcontrollers.

[0088] The aerosol generation system may comprise an aerosol generating device and one or more aerosol generating articles configured to be received within a recess of the aerosol generating device such that a susceptor located within the aerosol generating article is positioned within a varying electromagnetic field generated by an inductor. As described above, a method of using an aerosol generating article includes positioning the article in relation to an electrically operating aerosol generating device such that an 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 such that the power dissipated within the elongated susceptor is between 5 and 6 watts during a first period, and changing the magnetic field strength of the varying electromagnetic field such that the power dissipated within the elongated susceptor is between 1.5 and 2 watts during a second period.

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

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

[0091] A method of manufacturing an aerosol generating article described or defined herein may include the step of assembling a plurality of elements in the form of a rod having a mouth-side end and a distal end upstream from the mouth-side end, the plurality of elements including an aerosol-forming substrate and a susceptor in which an elongated susceptor element is arranged substantially longitudinally within the rod and which is in thermal contact with the aerosol-forming substrate. The susceptor preferably contacts the aerosol-forming substrate directly.

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

[0093] The elongated susceptor, or each elongated susceptor, can be inserted into the aerosol-forming substrate before assembling the aerosol-forming substrate with other elements to form an aerosol generating article. Alternatively, the aerosol-forming substrate can 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 apply to other aspects and embodiments. Specific embodiments will now be described with reference to the figures.

Brief Description of the Drawings

[0095]

Figure 1

Figure 2

Figure 3

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 a substantially cylindrical element, each having a substantially identical 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 central axis of the aerosol forming substrate.

[0097] The susceptor 25 is a ferrite 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 mouth-side end 70 that the 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 relative to the mouth-side end 70. The total length of the assembled aerosol generating article 10 is approximately 45 mm and the diameter is approximately 7.2 mm.

[0099] In use, air is drawn by the user from the distal end 80 through the aerosol-generating article towards the mouth-side end 70. Also, the distal end 80 of the aerosol-generating article may be described as the upstream end of the aerosol-generating article 10, and the mouth-side end 70 of the aerosol-generating article 10 may also be described as the downstream end of the aerosol-generating article 10. The elements of the aerosol-generating article 10 located between the mouth-side end 70 and the distal end 80 can be described as being upstream of the mouth-side 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 FIG. 1, the aerosol-forming substrate 20 comprises an assembly of crimped and homogenized tobacco material sheets surrounded by a wrapper. The crimped sheets of homogenized tobacco material contain 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 such that it can be penetrated by the susceptor 25 during manufacture of the aerosol-generating article 10. Thus, the support element 30 serves to prevent the aerosol-forming substrate 20 from being pushed downstream into the aerosol-generating article 10 towards the aerosol-cooling element 40 when the susceptor 25 is inserted into the aerosol-forming substrate 20. The support element 30 also acts as a spacer to space the aerosol-forming substrate 20 from the aerosol-cooling element 40 of the aerosol-generating article 10.

[0102] The aerosol cooling element 40 is positioned directly downstream of and adjacent to the support element 30. In use, the volatile substances released from the aerosol-forming substrate 20 pass along the aerosol cooling element 40 towards the mouth-side end 70 of the aerosol-generating article 10. The volatile substances 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 includes an assembly of crumpled sheets of polylactic acid surrounded by a wrapper 90. The assembly of crumpled sheets of polylactic acid defines a plurality of longitudinally extending paths along the length of the aerosol cooling element 40.

[0103] The mouthpiece 50 is positioned directly downstream of and adjacent to the aerosol cooling element 40. In the embodiment shown in FIG. 1, the 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 described above are aligned and closely wrapped within an outer wrapper 60. In the embodiment illustrated in FIG. 1, the outer wrapper is a conventional cigarette paper. Next, the susceptor 25 is inserted into the distal end 80 of the assembled article so as to penetrate the aerosol-forming substrate 20 to form a complete aerosol-generating article 10.

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

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

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

[0108] The aerosol generator 200 includes a battery 250 and an electronic circuit 260 for operating the inductor 210. Such operation may be manual or may occur automatically in response to the user pulling on the aerosol article 10 inserted into the base receiving chamber 230 of the aerosol generator 200.

[0109] When operating, a high-frequency alternating current passes through the winding coil that forms part of the inductor. This causes the inductor 210 to generate a varying electromagnetic field within the distal portion 231 of the base receiving recess 230 of the device. The frequency of the electromagnetic field preferably varies from 1 to 30 MHz, preferably from 2 to 10 MHz, for example from 5 to 7 MHz. When the aerosol article 10 is correctly positioned within the base receiving recess 230, the susceptor 25 of the article 10 is located within this varying electromagnetic field. The varying electromagnetic field generates eddy currents within the susceptor, as a result of which it is heated. The heated susceptor heats the aerosol-forming substrate 20 of the aerosol article 10 to a temperature sufficient to form an aerosol, for example to about 340°C. The aerosol is drawn downstream through the aerosol article 10 and inhaled by the user. FIG. 3 illustrates an aerosol article in conjunction with the electrically-operated aerosol generator.

[0110] The specific embodiments described in connection with FIG. 1 include an aerosol-forming substrate formed from homogenized tobacco. In other embodiments, the aerosol-forming substrate can be formed from different materials. For example, a second specific embodiment of the 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 containing nicotine pyruvate, glycerin, and water. The cigarette paper absorbs the liquid, so the non-tobacco sheet contains nicotine pyruvate, glycerin, and water. The ratio of glycerin to nicotine is 5:1. In use, the aerosol-forming substrate 20 is heated to a temperature of about 220 degrees Celsius. At this temperature, an aerosol containing nicotine pyruvate, glycerin, and water is released and can be drawn into the user's mouth through the filter 50. It is noted that the substrate 20 is heated to a temperature considerably lower than the temperature required for the aerosol to be released from the tobacco substrate.

[0111] In a 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 fluctuating 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, changing the power dissipated by the susceptor and thus changing the energy supplied to the aerosol-forming substrate during consumption of the article. This enables the aerosol-forming substrate to reach the use temperature, for example about 340 °C, rapidly, and then to be efficiently maintained at or near that temperature by supplying a lesser amount of energy.

[0112] It is not intended to limit the claims by the above exemplary embodiments. Other embodiments consistent with the above exemplary embodiments will be apparent to those skilled in the art.

Claims

1. 1. An aerosol-generating article for use with an electrically operated aerosol generating device, the aerosol-generating article comprising a plurality of elements assembled in the form of a rod having an oral end and a distal end upstream from the oral end, the plurality of elements including an aerosol-forming substrate, a support element and a mouthpiece; the support element is located immediately downstream of the aerosol-forming substrate, and the mouthpiece is located at the mouth end of the aerosol-generating article; the aerosol-forming substrate comprises one or more of a non-tobacco strip or sheet comprising an aerosol-forming material; the aerosol-forming substrate comprises a combination of two or more aerosol formers including propylene glycol and glycerin; a single elongated susceptor made of a susceptor material configured to convert electromagnetic energy into heat is located within the aerosol-forming substrate and in direct physical contact with the aerosol-forming substrate, the single elongated susceptor being positioned at a radially central portion within the rod and extending along a longitudinal axis of the rod; The aerosol-generating article, wherein the single elongated susceptor has a thickness of between 10 and 500 micrometers and is approximately the same length as the aerosol-forming substrate.

2. 2. The aerosol-generating article of claim 1, wherein the single elongated susceptor is in the shape of a pin, rod, or blade.

3. 3. The aerosol-generating article of claim 1 or 2, wherein the single elongated susceptor has a constant cross-section.

4. The aerosol-generating article of any one of claims 1 to 3, wherein the susceptor material comprises a ferromagnetic material.

5. The aerosol-generating article of any one of claims 1 to 4, wherein the susceptor material comprises a metal.

6. 6. An aerosol-generating article according to any one of claims 1 to 5, wherein the aerosol-forming substrate is in the form of a plug comprising the aerosol-forming material surrounded by a paper wrapper.

7. 7. An aerosol-generating article according to any one of claims 1 to 6, wherein the plurality of elements are surrounded by an outer wrapper.

8. The aerosol-generating article according to any one of claims 1 to 7, wherein the mouthpiece comprises a filter.

9. 9. The aerosol-generating article of claim 8, wherein the filter is formed from cellulose acetate tow.

10. 10. The aerosol-generating article according to any one of claims 1 to 9, wherein the mouthpiece has a length of between 5 millimetres and 20 millimetres.

11. An aerosol-generating article according to any one of claims 1 to 10, wherein the support element is formed from a polymeric material.

12. 12. An aerosol-generating article according to any one of the preceding claims, wherein the support element has a length of between 5 millimetres and 15 mm.

13. 13. An aerosol-generating article according to any one of claims 1 to 12, wherein the aerosol-forming substrate has a length of from 5 mm to 15 mm.

14. 14. The aerosol-generating article according to claim 13, wherein the aerosol-forming substrate has a length of between 8 mm and 12 mm.

15. 15. An aerosol-generating article according to any one of the preceding claims, wherein the total length of the aerosol-generating article is between 40mm and 50mm.

16. 16. An aerosol generation system comprising an electrically operated aerosol generating device having an inductor for generating a fluctuating electromagnetic field and an aerosol generating article as defined in any one of claims 1 to 15, said aerosol generating article cooperating with said aerosol generating device such that the fluctuating electromagnetic field generated by said inductor induces a current in said susceptor, thereby heating said susceptor.

17. 16. A method for producing an aerosol-generating article according to any one of claims 1 to 15, comprising assembling a plurality of elements into the form of a rod having an oral end and a distal end upstream of said oral end, said plurality of elements comprising an aerosol-forming substrate and a single elongated susceptor disposed substantially longitudinally within said rod and in thermal contact with said aerosol-forming substrate.

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