Aerosol-generating article for induction heating devices

Abstract

The present invention relates to an aerosol generating article for use with an aerosol generating device. The article comprises a susceptor element (32) including a hollow tubular proximal region (34) and a closed distal end (36). The article comprises a hollow tubular core element (42) coaxially surrounding at least a portion of the hollow tubular proximal region of the susceptor element. The present invention further relates to an aerosol generating system.

Description

[Technical field]

[0001] The present disclosure relates to an aerosol generating article for an aerosol generating device.The present disclosure further relates to an aerosol generating system comprising an aerosol generating device and an aerosol generating article. [Background technology]

[0002] It is known to provide an aerosol generating device for generating an inhalable vapor. Such a device may heat an aerosol-forming substrate contained in an aerosol-generating article without combustion. The heating arrangement may be an induction heating arrangement and may include an induction coil and a susceptor. The susceptor may be part of the device or part of the article.

[0003] The aerosol-generating article may have a shape suitable for insertion of the aerosol-generating article into the heating chamber of the aerosol-generating device. For example, the aerosol-generating article may have a rod shape. A heating element may be disposed in or around the heating chamber to heat the aerosol-forming substrate when the aerosol-generating article is inserted into the heating chamber of the aerosol-generating device. When heated to a target temperature, the aerosol-forming substrate vaporizes to form an aerosol.

[0004] The aerosol-generating article may include a solid aerosol-forming substrate. Alternatively, a liquid aerosol-forming substrate may be delivered to the electric heating element from a liquid storage portion. The liquid substrate may be delivered to the heating element via a capillary component. The liquid storage portion may be formed as a replaceable or refillable cartridge containing the liquid aerosol-forming substrate. The cartridge may be attached to an aerosol generating device to supply the liquid aerosol-forming substrate to the device for aerosol generation.

[0005] It is desirable to provide an aerosol-generating article comprising a liquid aerosol-forming substrate.It is desirable to provide an aerosol-generating article comprising a liquid aerosol-forming substrate that can be used with existing inductively heated aerosol generating devices configured for inductively heating an aerosol-generating article comprising a solid aerosol-forming substrate.It is desirable to provide a compact aerosol-generating article comprising a liquid aerosol-forming substrate.It is desirable to provide an aerosol-generating article comprising a liquid aerosol-forming substrate that is leak-proof. Summary of the Invention

[0006] According to an embodiment of the present invention, there is provided an aerosol-generating article for use with an aerosol-generating device. The article may comprise a susceptor element. The susceptor element may include a hollow tubular proximal region. The susceptor element may include a closed distal end. The article may comprise a hollow tubular core element. The hollow tubular core element may coaxially surround at least a portion of the hollow tubular proximal region of the susceptor element.

[0007] According to an embodiment of the invention, there is provided an aerosol-generating article for use with an aerosol generating device, the article comprising a susceptor element including a hollow tubular proximal region and a closed distal end, the article comprising a hollow tubular core element coaxially surrounding at least a portion of the hollow tubular proximal region of the susceptor element.

[0008] An aerosol-generating article is provided that can be compactly designed to fit into the narrow heating chamber of an aerosol-generating device that is also designed for inductively heating tobacco-containing consumables. Such consumables typically have an outer diameter of 5 mm to 10 mm, preferably 6 mm to 8 mm. The hollow heating chamber has an inner diameter that is slightly wider than the outer diameter of the consumable.

[0009] The closed distal end of the aerosol-generating article may help prevent leakage. For example, droplets that may be present inside the hollow tubular proximal region due to a portion of the liquid aerosol-forming substrate that has not evaporated or that has recondensed as droplets on the inner wall may move toward the closed distal end by gravity or capillary forces. The droplets may be prevented from exiting the susceptor by the closed distal end. Thereby, leakage may be avoided.

[0010] The closed distal end may be fluid impermeable.

[0011] The closed distal end may be configured as a cup-shaped distal end region.

[0012] The cup-shaped distal end region may provide a collection reservoir for collecting condensed droplets.

[0013] The cup-shaped distal end region may provide a mechanism for preventing leakage. For example, liquid droplets that may be present inside the hollow tubular proximal region due to a portion of the unevaporated liquid aerosol-forming substrate may move toward the cup-shaped distal end region by gravity or capillary forces. The liquid droplets may then be trapped in the collection reservoir. Thereby, leakage may be avoided.

[0014] At least a portion of the susceptor element may be fluid permeable. At least a portion of the hollow tubular proximal region of the susceptor element may be fluid permeable. At least a portion of the hollow tubular proximal region of the susceptor element may be fluid permeable and the closed distal end may be fluid impermeable.

[0015] One or both of the hollow tubular proximal region and the closed distal end of the susceptor element may comprise a porous susceptor material.

[0016] The porous susceptor material may have a porosity of between 45% and 80%, preferably between 55% and 70%.

[0017] As used herein, "porosity" is defined as the percentage of a unit volume that is void in a material. Porosity is derived using standard methods and equations, which give a decimal value for porosity. By knowing the pore volume (Vp) of a defined volume of material and its total volume (Vt), the porosity (Pt) is given by the ratio Vp / Vt. To express porosity as a percentage, simply multiply the decimal by 100%. For example, Pt=0.51, so 0.51×100%=51%.

[0018] The porous susceptor material may be a ferromagnetic alloy, preferably a ferromagnetic stainless steel alloy, more preferably 304 stainless steel or 410 stainless steel.

[0019] The hollow tubular proximal region and the closed distal end of the susceptor element may form a monolithic structure.

[0020] The entire susceptor element, including the tubular proximal region and the closed distal end, may be a monolithic structure. The monolithic structure may be fluid permeable. The monolithic structure may be porous. The monolithic structure may include a fluid impermeable coating in the region of the closed distal end.

[0021] The aerosol-generating article may include an airflow path extending along a central longitudinal axis of the hollow tubular proximal region of the susceptor element.

[0022] The aerosol-generating article may include one or more air inlets located proximal to the closed distal end.

[0023] The size, number and arrangement of the one or more air inlets may be configured to predetermine the overall draw resistance of the aerosol-generating article.

[0024] In use, when the aerosol-generating article is inserted into an aerosol generating device, the withdrawal retention force, also referred to as the resistance to withdrawal (RTD), of the aerosol-generating article may be in the range 50 to 200 mm of water column, preferably 100 to 160 mm of water column, more preferably 120 to 140 mm of water column.

[0025] The one or more air inlets may be arranged so that the overall draw resistance of the aerosol-generating article is in the range 50 to 200 mm of water column, preferably 100 to 160 mm of water column, more preferably 120 to 140 mm of water column.

[0026] The core element may be a monolithic element.

[0027] The core element may comprise a ceramic material. The core element may comprise a porous material. The core element may comprise a porous ceramic material. The core element may comprise a porous silica ceramic. The porosity of the sintered material can be adjusted by varying the content of the introduced silica particles and varying their particle size, which allows good control of the desired porosity of the final product.

[0028] The porosity of the core element may be from 45% to 80%, preferably from 50% to 65%, and most preferably from 50% to 60%.

[0029] The aerosol-generating article may comprise a hollow tubular liquid storage portion coaxially surrounding the core element. The liquid storage portion may include one or both of a liquid aerosol-forming substrate and a liquid sensory medium. The liquid aerosol-forming substrate or liquid sensory medium may include nicotine. The liquid aerosol-forming substrate or liquid sensory medium may include botanical content, such as CBD.

[0030] The hollow tubular liquid storage portion may include a high retention material adjacent a side wall of the core element. The high retention material is provided in the form of a hollow tubular element coaxially surrounding the core element. The hollow tubular element of high retention material may have an outer diameter of between 4 millimeters and 6.5 millimeters. The high retention material may be a porous material. The high retention material may include cotton. The high retention material may include a capillary material as described herein. The high retention material may help ensure wettability of the core element. The high retention material may help ensure that the core element is constantly supplied with liquid from the liquid storage portion.

[0031] The aerosol-generating article may comprise a fluid-permeable wall element provided at the interface between the high-retention material and the core element. The aerosol-generating article may comprise a porous wall element provided at the interface between the high-retention material and the core element. The porosity of the wall element may be between 50% and 90%, preferably between 50% and 80%.

[0032] The aerosol-generating article may comprise a mouthpiece or mouthpiece element. The mouthpiece or mouthpiece element may include a homogenization chamber. The homogenization chamber may allow for one or both of expansion, homogenization, and cooling of the aerosol before it exits the mouthpiece element for inhalation by the user.

[0033] The mouthpiece may include a tubular core element. The tubular core element may be configured to reduce condensation formation. The tubular core element may include a tubular wall. The tubular core element may be disposed at the center of the mouthpiece. The tubular core element may be disposed centrally along the longitudinal axis of the aerosol-generating article. The tubular core element may have an inner diameter measured in a direction perpendicular to the longitudinal axis of the aerosol-generating article. The inner diameter of the tubular core element of the mouthpiece may be smaller than the inner diameter of the outer tubular wall of the mouthpiece. The inner diameter of the tubular core element may be 1 / 3 of the diameter of the mouthpiece. The tubular core element of the mouthpiece may have a length measured in a direction along the longitudinal axis of the aerosol-generating article. The length of the tubular core element may be smaller than the length of the mouthpiece measured in the same direction. The length of the tubular core element may be about 1 / 2 the length of the mouthpiece. After exiting the tubular core element, the velocity of the aerosol flow may decrease. The aerosol may be further homogenized after exiting the tubular core element. The inside of the tubular wall of the tubular core element may be exposed to a higher temperature than the outside of the tubular wall. The tubular core element may prevent or reduce condensation formation. Condensation of the aerosol and droplet formation on the inside of the tubular wall of the tubular core element may be prevented or reduced. During use, the tubular wall of the tubular core element may have a higher temperature than the outer tubular wall of the mouthpiece. Thereby, condensation formation may be prevented or reduced.

[0034] The mouthpiece may include a high retention material configured to prevent condensation. As used herein, a "high retention material" is a material that has the ability to absorb and / or store liquid and to transport liquid (e.g., by capillary action). For example, liquid may be transported away from the inside of the outer tubular wall of the mouthpiece. The liquid aerosol-forming substrate or liquid residue of the aerosol-forming substrate may condense on the inside of the outer tubular wall of the mouthpiece. The high retention material may surround the tubular core element of the mouthpiece. The high retention material may surround a distal portion of the tubular core element of the mouthpiece. Thereby, condensation may be absorbed when the aerosol-generating article is oriented in an upright position with the distal end facing the center of gravity. The high retention material may be, for example, cotton.

[0035] The mouthpiece element may include one or more peelable outer layers.

[0036] The aerosol-generating article may have a cylindrical shape and the outer diameter of the article may be between 5 mm and 10 mm, preferably between 6 mm and 8 mm.

[0037] The aerosol-generating article may include a proximal sealing element at a proximal end of the core element. The aerosol-generating article may include a distal sealing element at a distal end of the core element. One or both of the proximal and distal sealing elements may be in the form of a sealing disk. One or both of the proximal and distal sealing elements may provide an air barrier and may hold and assemble the susceptor element and the core element.

[0038] The aerosol-generating article may comprise a capping element disposed at a distal end thereof. The capping element may comprise a hollow tubular wall element. The capping element may comprise one or more recesses disposed circumferentially at the distal end of the hollow tubular wall element. The capping element may comprise one or more inlet holes, preferably elongated openings, disposed circumferentially within the hollow tubular wall element.

[0039] The recess or inlet hole may allow ambient air to enter the article at its distal end when the article contacts a flat surface, for example when the article is inserted into a heating chamber of an aerosol generating device against a flat distal base of the heating chamber.

[0040] The present invention further relates to an aerosol generation system comprising an aerosol-generating article as described herein and an aerosol generating device including a heating chamber for inserting at least a portion of the article, and an inductor coil at least partially surrounding the heating chamber for inductively heating the aerosol-generating article.

[0041] The liquid storage portion of the aerosol-generating article may include one or both of a liquid aerosol-forming substrate and a liquid sensory medium. The liquid sensory medium may include a flavoring agent. The liquid sensory medium may include nicotine. The liquid aerosol-forming substrate or liquid sensory medium may include a flavoring agent, such as menthol or an herbal compound. The liquid aerosol-forming substrate or liquid sensory medium may include nicotine. The liquid aerosol-forming substrate or liquid sensory medium may include botanical content, such as CBD.

[0042] The core element may comprise cotton.The core element may be made from cotton.

[0043] The wick element may be a porous element. The wick element may have the ability to absorb liquid from the air stream. The wick element may include a capillary material. The capillary material may have a fibrous or cavernous structure. The capillary material preferably includes a bundle of capillaries. For example, the capillary material may include a plurality of fibers or threads, or other fine tubes. The fibers or threads may be generally aligned to transport liquid from a distal portion of the core element to a proximal portion of the core element. Alternatively, the capillary material may include a cavernous or foam-like material. The structure of the capillary material may form a plurality of small holes or tubes through which liquid can be transported by capillary action. The capillary material may include any suitable material or combination of materials. Examples of suitable materials are sponge or foam materials, ceramic or graphite-based materials in the form of fibers or sintered powders, foamed metal or plastic materials, fibrous materials, such as fibrous materials made of spun or extruded fibers (such as cellulose acetate, polyester, or bonded polyolefin, polyethylene, ethylene or polypropylene fibers, nylon fibers or ceramics). The capillary material may have any suitable capillary action and porosity to be used with different liquid physical properties. The liquid has physical properties including, but not limited to, viscosity, surface tension, density, thermal conductivity, boiling point, and vapor pressure that allow the liquid to be moved through the capillary material by capillary action. The capillary material may be configured to carry the aerosol-forming substrate to the proximal portion of the wick element and to the susceptor element. The capillary material may extend into the gaps in the susceptor element.

[0044] As used herein, the term "liquid sensory medium" refers to a liquid composition capable of modifying an airflow that contacts the liquid sensory medium. The modification of the airflow may be one or more of forming an aerosol or vapor, cooling the airflow, and filtering the airflow. For example, the liquid sensory medium may include an aerosol-forming substrate capable of releasing a volatile compound capable of forming an aerosol or vapor. The aerosol-forming substrate in the liquid sensory medium is preferably a flavorant or includes a flavorant. Alternatively, or additionally, the liquid sensory medium may include one or both of a cooling material for cooling the airflow passing through the liquid sensory medium and a filtering material for capturing undesirable components in the airflow. Water may be used as a cooling material. Water may be used as a filtering material for capturing particles, such as dust particles, from the airflow. The liquid sensory medium may function as one or more of a nicotine-delivering liquid, a flavoring, and a bulking agent.

[0045] As used herein, the term "aerosol-forming substrate" refers to a substrate capable of releasing a volatile compound capable of forming an aerosol or vapor. Such a volatile compound may be released by heating the aerosol-forming substrate. The aerosol-forming substrate may be in solid or liquid form. The terms "aerosol" and "vapor" are used interchangeably.

[0046] The aerosol-forming substrate may be part of the aerosol-generating article. The aerosol-forming substrate may be part of a liquid held in a liquid storage portion of the aerosol-generating article. The aerosol-forming substrate may be part of a liquid sensory medium held in a liquid storage portion of the aerosol-generating article. The liquid storage portion may contain a liquid aerosol-forming substrate. Alternatively, or additionally, the liquid storage portion may contain a solid aerosol-forming substrate. For example, the liquid storage portion may contain a suspension of a solid aerosol-forming substrate and a liquid. The liquid storage portion preferably contains a liquid aerosol-forming substrate.

[0047] Preferably, the liquid nicotine or flavour / flavour-containing aerosol-forming substrate may be employed in the liquid storage portion of the aerosol-generating article.

[0048] The aerosol-forming substrate may comprise nicotine. The nicotine-containing aerosol-forming substrate may be a nicotine salt matrix.

[0049] The aerosol-forming substrate may comprise a plant-derived material. The aerosol-forming substrate may comprise tobacco. The aerosol-forming substrate may comprise a tobacco-containing material comprising volatile tobacco flavour compounds which are released from the aerosol-forming substrate upon heating. Alternatively, the aerosol-forming substrate may comprise a non-tobacco material. The aerosol-forming substrate may comprise a homogenised plant-derived material. The aerosol-forming substrate may comprise a homogenised tobacco material. The homogenised tobacco material may be formed by agglomerating particulate tobacco.

[0050] The aerosol-forming substrate may include at least one aerosol former. The aerosol former is any suitable known compound or mixture of compounds that facilitates the formation of a dense, stable aerosol in use and is substantially resistant to thermal decomposition at the operating temperature of the device. Suitable aerosol formers are well known in the art and include, but are not limited to, polyhydric alcohols (such as triethylene glycol, 1,3-butanediol, glycerin, etc.), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate, etc.), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.). A preferred aerosol former is a polyhydric alcohol or mixtures thereof (such as triethylene glycol, 1,3-butanediol, etc.). Preferably, the aerosol former is glycerin. When present, the homogenized tobacco material may have an aerosol former content of 5 weight percent or more on a dry weight basis, and preferably has an aerosol former content of 5 weight percent to 30 weight percent on a dry weight basis. The aerosol-forming substrate may contain other additives and ingredients, such as flavourants.

[0051] As used herein, the term "aerosol-generating article" refers to an article that includes an aerosol-forming substrate capable of releasing a volatile compound capable of forming an aerosol. For example, the aerosol-generating article may be an article that generates an aerosol that can be directly inhaled by a user sucking or puffing on a mouthpiece at the proximal or user end of the device. The aerosol-generating article may be disposable. The aerosol-generating article may be insertable into a heating chamber of an aerosol-generating device.

[0052] As used herein, the term "liquid reservoir" refers to a reservoir that includes a liquid sensory medium and, additionally or alternatively, an aerosol-forming substrate capable of releasing a volatile compound capable of forming an aerosol. The liquid reservoir may be configured as a container or reservoir for storing the liquid aerosol-forming substrate.

[0053] The liquid reservoir may be configured as a replaceable tank or container. The liquid reservoir may be of any suitable shape and size. For example, the liquid reservoir may be substantially cylindrical. The cross section of the liquid reservoir may be, for example, substantially circular, elliptical, square, or rectangular.

[0054] As used herein, the term "aerosol-generating device" refers to a device that interacts with an aerosol-generating article and / or a cartridge to generate an aerosol.

[0055] As used herein, the term "aerosol generating system" refers to a combination of an aerosol generating device and one or both of a cartridge and an aerosol generating article, in which the aerosol generating device and one or both of the aerosol generating article and cartridge cooperate to generate a respirable aerosol.

[0056] The aerosol generating device is preferably portable. The aerosol generating device may have a size comparable to a conventional cigar or cigarette. The device may be an electrically operated smoking device. The device may be a handheld aerosol generating device. The aerosol generating device may have a total length of between 30 mm and 150 mm. The aerosol generating device may have an outer diameter of between 5 mm and 30 mm.

[0057] The aerosol generating device may comprise a housing. The housing may be elongated. The housing may comprise any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics, or composites containing one or more of these materials, or thermoplastics suitable for food or pharmaceutical applications, such as polypropylene, polyetheretherketone (PEEK), polyethylene. Preferably, the material is light and not brittle.

[0058] The housing may include at least one air inlet. The housing may include multiple air inlets.

[0059] The aerosol generating device may include a heating element, which may include at least one inductor coil for inductively heating one or more susceptors.

[0060] Operation of the heating element may be triggered by a puff detection system. Alternatively, the heating element may be triggered by pressing an on-off button and held for the duration of the user's puff. The puff detection system may be provided as a sensor, which may be configured as an airflow sensor for measuring airflow velocity. Airflow velocity is a parameter that characterizes the amount of air per time drawn by the user through the airflow path of the aerosol generating device. The start of a puff may be detected by the airflow sensor when the airflow exceeds a predefined threshold. The start may also be detected after the user activates the button. The sensor may also be configured as a pressure sensor.

[0061] The aerosol generating device may include a user interface for activating the aerosol generating device, such as a button to initiate heating of the aerosol generating device, or a display to indicate the status of the aerosol generating device or the aerosol-forming substrate.

[0062] The aerosol generating device may include additional components, such as, for example, an electrically operated or charging unit for recharging an on-board power supply within an electric aerosol generating device.

[0063] As used herein, the term "proximal" refers to the user or mouth end of an aerosol generating device or system or portion thereof, and the term "distal" refers to the end opposite the proximal end. When referring to a heating chamber, the term "proximal" refers to the area closest to the open end of the cavity, and the term "distal" refers to the area closest to the closed end.

[0064] As used herein, the terms "upstream" and "downstream" are used to describe the relative location of a component or portion of a component of an aerosol generating device with respect to the direction in which a user draws on the aerosol generating device when the aerosol generating device is in use.

[0065] The term "airflow path" as used herein means a channel suitable for transporting a gaseous medium. The airflow path may be used to transport ambient air. The airflow path may be used to transport an aerosol. The airflow path may be used to transport a mixture of air and an aerosol.

[0066] As used herein, "susceptor" or "susceptor element" refers to an element that heats up when subjected to an alternating magnetic field. This may be the result of eddy currents induced in the susceptor element, or hysteresis losses, or both eddy currents and hysteresis losses. In use, the susceptor element is positioned in thermal contact or thermal proximity with an aerosol-forming substrate received in an aerosol-generating device or aerosol-generating article. In this manner, the aerosol-forming substrate is heated by the susceptor, thereby forming an aerosol.

[0067] The susceptor material may be any material that can be inductively heated to a temperature sufficient to aerosolize the aerosol-forming substrate. The following examples and features relating to the susceptor may apply to one or both of the susceptor element of the cartridge, the susceptor of the aerosol-generating device, and the susceptor of the aerosol-generating article. Suitable materials for the susceptor material include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium, and composites of metallic materials. Preferred susceptor materials include metals or carbon. Advantageously, the susceptor material may include or consist of ferromagnetic or ferrimagnetic materials, such as, for example, ferritic iron, ferromagnetic alloys (such as ferromagnetic steel or stainless steel), ferromagnetic particles, ferrites, and the like. A suitable susceptor material may be or include aluminum. The susceptor material may contain more than 5 percent, preferably more than 20 percent, more preferably more than 50 percent or more than 90 percent ferromagnetic, ferrimagnetic, or paramagnetic material. Preferred susceptor materials may be heated to temperatures in excess of 250 degrees Celsius without degradation.

[0068] The susceptor material may be formed from a single layer of material, which may be a layer of steel.

[0069] The susceptor material may comprise a non-metallic core having a metallic layer disposed thereon. For example, the susceptor material may comprise a ceramic core or a metallic track formed on the outer surface of the substrate.

[0070] The susceptor material may be formed from a layer of austenitic steel. One or more layers of stainless steel may be disposed on the layer of austenitic steel. For example, the susceptor material may be formed from a layer of austenitic steel having a layer of stainless steel on each of its upper and lower surfaces. The susceptor element may include a single susceptor material. The susceptor element may include a first susceptor material and a second susceptor material. The first susceptor material may be disposed in intimate physical contact with the second susceptor material. The first susceptor material and the second susceptor material may be in intimate contact to form a single susceptor that cannot be disassembled. In certain embodiments, the first susceptor material is stainless steel and the second susceptor material is nickel. The susceptor element may have a bi-layer structure. The susceptor element may be formed from a stainless steel layer and a nickel layer.

[0071] The intimate contact between the first and second susceptor materials may be achieved by any suitable means. For example, the second susceptor material may be plated, deposited, coated, clad, or welded onto the first susceptor material. Preferred methods include electroplating, galvanizing, and cladding.

[0072] The aerosol generating device may be a power source for powering the heating element. The power source may comprise a battery. The power source may be a lithium-ion battery. Alternatively, the power source may be a nickel metal hydride battery, a nickel cadmium battery, or a lithium-based battery (e.g., a lithium cobalt battery, a lithium iron phosphate battery, a lithium titanate battery, or a lithium polymer battery). The power source may require recharging and may have a capacity that allows for storage of sufficient energy for one or more use experiences. For example, the power source may have a capacity sufficient to continuously generate aerosol for about six minutes, or a multiple of six minutes. In another embodiment, the power source may have a capacity sufficient to provide a predetermined number of puffs, or discontinuous activation of the heating element.

[0073] The power source may be a direct current (DC) power source. In one embodiment, the power source is a DC power source having a DC supply voltage in the range of 2.5 volts to 4.5 volts and a DC supply current in the range of 1 amp to 10 amps (corresponding to a DC power source in the range of 2.5 watts to 45 watts). The aerosol generating device may advantageously comprise a direct current to alternating current (DC / AC) inverter for converting the DC current provided by the DC power source to an alternating current. The DC / AC converter may comprise a class D, class C, or class E power amplifier. The AC power output of the DC / AC converter is provided to the induction coil.

[0074] The power source may be adapted to supply power to the inductor coil and may be configured to operate at high frequencies. For operation at high frequencies, a class E power amplifier is preferred. As used herein, the term "high frequency oscillating current" refers to an oscillating current having a frequency between 500 kilohertz and 30 megahertz. The high frequency oscillating current may have a frequency between 1 megahertz and 30 megahertz, preferably between 1 megahertz and 10 megahertz, and more preferably between 5 megahertz and 8 megahertz.

[0075] In alternative embodiments, the switching frequency of the power amplifier may be in the lower kHz range, for example 100 kHz to 400 KHz. In embodiments where class D or class C power amplifiers are used, switching frequencies in the lower kHz range are particularly advantageous.

[0076] The aerosol generating device may comprise a controller. The controller may be electrically connected to the inductor coil. The controller may be electrically connected to the first induction coil and to the second induction coil. The controller may be configured to control the current supplied to the induction coil and therefore the magnetic field strength generated by the induction coil.

[0077] A power source and a controller may be connected to the inductor coil.

[0078] The controller may be configured to chop the current supply on the input side of the DC / AC converter, so that the power supplied to the inductor coil can be controlled by conventional methods of duty cycle management. EXAMPLES

[0079] The following provides a non-exhaustive list of non-limiting examples, any one or more of the features of which may be combined with any one or more features of the other examples, embodiments, or aspects described herein.

[0080] Example A: 1. An aerosol-generating article for use with an aerosol generating device, comprising: a susceptor element including a hollow tubular proximal region and a closed distal end; a hollow tubular core element coaxially surrounding at least a portion of the hollow tubular proximal region of the susceptor element. Example B: The article according to embodiment A, wherein the closed distal end is configured as a cup-shaped distal end region. Example C: The article according to embodiment B, wherein the cup-shaped distal end region provides a collection reservoir for collecting condensed droplets. Example D: An assembly according to any of Examples A to C, wherein at least a portion of the susceptor element, preferably at least a portion of the hollow tubular proximal region of the susceptor element, is fluid-permeable, more preferably at least a portion of the hollow tubular proximal region of the susceptor element is fluid-permeable and the closed distal end is fluid-impermeable. Example E: The article according to example D, wherein one or both of the hollow tubular proximal region and the closed distal end of the susceptor element comprise a porous material. Example F: The article according to embodiment E, wherein the porous material has a porosity of 45% to 80%, preferably 55% to 70%. Example G: The article according to Example E or Example F, wherein the porous material is a ferromagnetic alloy, preferably a ferromagnetic stainless steel alloy, more preferably 304 stainless steel or 410 stainless steel. Example H: The article according to any of embodiments A-G, wherein the hollow tubular proximal region and the closed distal end of the susceptor element form a monolithic structure. Example I: The article according to any of embodiments A-H, comprising an airflow path extending along the longitudinal central axis of the hollow tubular proximal region of the susceptor element. Example J: The article according to any of claims A-I, comprising one or more air inlets located proximal to the closed distal end. Example K: The article according to embodiment J, wherein the size, number, and arrangement of the one or more air inlets are configured to predetermine the overall resistance to withdrawal of the article. Example L: The article according to embodiment K, wherein the one or more air inlets are arranged such that the overall drawing resistance of the article is in the range of 50 to 200 mm of water column, preferably 100 to 160 mm of water column, more preferably 120 to 140 mm of water column. Example M: The article according to any of claims A-L, comprising a hollow tubular liquid storage portion coaxially surrounding the core element. Example N: The article according to embodiment M, wherein the hollow tubular liquid storage portion comprises a high retention material adjacent to the sidewall of the core element. Example O: The article according to example N, comprising a porous wall element provided at an interface between the high retention material and the core element. Example P: The article according to any of Examples A-O, comprising a mouthpiece element. Example Q: The article according to embodiment P, wherein the mouthpiece element comprises one or more peelable outer layers. Example R: The article according to any of Examples A-Q, wherein the article has a cylindrical shape and an outer diameter of the article is between 5 millimeters and 10 millimeters, preferably between 6 millimeters and 8 millimeters. Example S: The article according to any of embodiments A-R, wherein the closed distal end is fluid impermeable. Example T: 1. An aerosol generation system comprising: An article according to any one of Examples A to S; an aerosol generating device including a heating chamber for inserting at least a portion of an article, and an inductor coil at least partially surrounding the heating chamber for inductively heating the article.

[0081] Features described with respect to one embodiment may be equally applied to other embodiments of the invention.

[0082] The invention will now be further described, by way of example only, with reference to the accompanying drawings in which: [Brief description of the drawings]

[0083] [Figure 1] Figure 1a shows an aerosol-generating article, and Figure 1b shows an aerosol-generating article. [Diagram 2] FIG. 2 shows a portion of an aerosol-generating article. [Diagram 3] Figure 3a shows the mouthpiece element, and Figure 3b shows the mouthpiece element. [Figure 4] 4a and 4b show a portion of an aerosol-generating article. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0084] FIG. 1a shows two perspective views of an elongated cylindrical aerosol-generating article 10. The article 10 comprises a mouthpiece element 12 disposed at a proximal end of the article 10. The article 10 further comprises a cartridge section. The cartridge section includes a hollow tubular liquid storage portion 14 surrounding an inner channel 16. The hollow tubular liquid storage portion 14 holds a liquid aerosol-forming substrate 18. The cartridge section includes a susceptor and wick assembly 20 disposed within the inner channel 16 and surrounded by the liquid storage portion 14. The susceptor and wick assembly 20 is described in more detail below with respect to FIG. 2 below. The hollow tubular liquid storage portion 14 includes a high retention material 22 adjacent to a sidewall of the susceptor and wick assembly 20.

[0085] The article 10 includes a capping element 24 disposed at a distal end thereof. The capping element 24 includes a hollow tubular wall element 26. The capping element 24 includes a plurality of recesses 28 circumferentially disposed at the distal end of the hollow tubular wall element 26.

[0086] Figure 1b shows two perspective views of an aerosol-generating article 10. The article 10 shown in Figure 1b is identical to the article 10 of Figure 1a, except that the capping element 24 of Figure 1b does not include recesses 28. Instead, the capping element 24 of Figure 1b includes a plurality of elongated openings 30 circumferentially disposed within a hollow tubular wall element 26.

[0087] The recess 28 or elongated opening 30 may allow ambient air to enter the article at its distal end when the article contacts a flat surface, for example, when the article is inserted into a heating chamber of an aerosol generating device against a flat distal base of the heating chamber.

[0088] Figure 2 shows a distal portion of the aerosol-generating article of Figure 1b, showing in more detail the susceptor and wick assembly 20. The area of ​​the susceptor and wick assembly 20 is indicated by a dotted rectangle for illustrative purposes.

[0089] The susceptor and wick assembly 20 includes a susceptor element 32. The susceptor element 32 includes a hollow tubular proximal region 34 and a closed distal end. The closed distal end is configured as a cup-shaped distal end region 36. The cup-shaped distal end region 36 provides a collection reservoir 38 for collecting condensed droplets.

[0090] The susceptor element 32 includes a plurality of air inlets 40 located proximal to the closed cup-shaped distal end region 36. The size, number, and arrangement of the air inlets 40 are configured to predetermine the overall resistance to drawing of the article.

[0091] The susceptor and core assembly 20 includes a hollow tubular core element 42 that coaxially surrounds most of the hollow tubular proximal region 34 of the susceptor element 32 , except for a distal portion thereof that includes the air inlet 40 .

[0092] At least a majority of the hollow tubular proximal region 34 surrounded by the core element 42 is fluid permeable. The entire susceptor element 32, including the tubular proximal region 34 and the cup-shaped distal end region 36, may be a monolithic structure. The monolithic structure may be fluid permeable. The monolithic structure may be porous. The monolithic structure may include a fluid impermeable coating in the area of ​​the cup-shaped distal end region 36.

[0093] The hollow tubular liquid storage portion 14 coaxially surrounds the core element 42. The hollow tubular liquid storage portion 14 includes a high retention material 22 adjacent to a sidewall of the core element 42. A porous, fluid permeable inner wall element 44 is provided at the interface between the high retention material 22 and the core element 42.

[0094] The liquid aerosol-forming substrate 18 stored within the liquid storage portion 14 can migrate into and through the high-retentive material 22, then through the fluid-permeable inner wall element 44, and into and through the core element 42 to wet the hollow tubular proximal region 34 of the susceptor element 32. When the susceptor element 32 is inductively heated, the liquid aerosol-forming substrate 18 located in the hollow tubular proximal region 34 can be heated and volatilized to form an aerosol.

[0095] The cup-shaped distal end region 36 of the susceptor element 32 provides a mechanism for preventing leakage. For example, liquid droplets that may be present inside the hollow tubular proximal region 34 due to a portion of the unvaporized liquid aerosol-forming substrate may migrate toward the cup-shaped distal end region 36 by gravity or capillary forces. The liquid droplets are then trapped in the collection reservoir 38. Thereby, leakage may be avoided.

[0096] In a region proximal to the susceptor and wick assembly 20, a fluid-impermeable inner wall element 46 of the liquid storage portion 14 surrounds the inner channel 16. A distal end of the fluid-impermeable inner wall 46 includes a first protrusion 48. A proximal end portion 50 of the susceptor and wick assembly 20 is secured and sealed to the fluid-impermeable inner wall 46 via the first protrusion 48.

[0097] The capping element 24 is fixed and sealed by fixing its tubular wall element 26 to the outer wall 52 of the liquid storage portion 14 via the second projection 54. Instead of the elongated opening 30, the capping element 74 may include a recess 28, as shown in FIG.

[0098] A proximal sealing element 56 in the form of a sealing disc is provided at the proximal end of the core element 42. A distal sealing element 58 in the form of a sealing disc is provided at the distal end of the core element 42. The distal sealing element 56 provides an air seal and holds and assembles the susceptor element 32 and the core element 42.

[0099] The article 10 comprises an airflow path extending along the longitudinal central axis of the hollow tubular proximal region 34 of the susceptor element 32. Air may enter the article 10 through the elongated opening 30 at the distal end and further enter the airflow path within the susceptor element 32 via the air inlet 40. The incoming air may be preheated when it approaches the hot susceptor element 32 and when it enters the hollow susceptor element 32 via the air inlet 40. In the region of the axis of the hollow tubular proximal region 34, an aerosol is formed when the susceptor element 32 is inductively heated to volatilize the liquid aerosol-forming substrate transferred to the susceptor element 32. The airflow path is visualized by the dotted arrows in Figures 4a and 4b. The airflow containing the volatilized compounds of the aerosol-forming substrate further travels through the inner channel 16 into the mouthpiece 12, from where the mature aerosol leaves the article and is inhaled by the user.

[0100] 3a and 3b each show the mouthpiece element 12 attached to the top of the proximal end of the cartridge section of the aerosol-generating article 10. Shown are the hollow tubular liquid storage portion 14, the inner channel 16, the liquid aerosol-forming substrate 18, and the proximal portion of the outer wall 52. The mouthpiece element 12 includes a homogenization chamber 60. The homogenization chamber 60 is fluidly connected to the inner channel 16. The homogenization chamber 60 allows for expansion, homogenization, and cooling of the aerosol before it exits the mouthpiece element 12 for inhalation by the user.

[0101] Unlike the mouthpiece element 12 of Fig. 3b, the outer sidewall of the mouthpiece element 12 of Fig. 3a includes multiple layers of peelable outer layers 60. Each layer of the peelable outer layers 62 is removably adhered onto an adjacent inner layer. Thus, the individual layers provide segments that can be individually peeled away, thereby providing a hygienic mouthpiece.

[0102] After use of the article, the used layer can be peeled away so that a clean surface is present for the next use or next user.

[0103] Figures 4a and 4b show cross-sectional views of a portion of an aerosol-generating article, similar to that shown in Figure 2. As mentioned above, the airflow paths are visualized by the dotted arrows.

[0104] Additionally, Figures 4a and 4b show suitable length ranges and preferred specific component lengths, with corresponding values ​​listed in Table 1 below. [Table 1]

Claims

1. 1. An aerosol-generating article for use with an aerosol-generating device, comprising: a susceptor element including a hollow tubular proximal region and a closed distal end; a hollow tubular core element coaxially surrounding at least a portion of the hollow tubular proximal region of the susceptor element.

2. The article of claim 1 , wherein the closed distal end is configured as a cup-shaped distal end region.

3. The article of claim 2 , wherein the cup-shaped distal end region provides a collection reservoir for collecting condensed liquid droplets.

4. 4. An assembly according to any one of claims 1 to 3, wherein at least a portion of the susceptor element, preferably at least a portion of the hollow tubular proximal region of the susceptor element, is fluid permeable, more preferably at least a portion of the hollow tubular proximal region of the susceptor element is fluid permeable and the closed distal end is fluid impermeable.

5. The article of claim 4 , wherein one or both of the hollow tubular proximal region and the closed distal end of the susceptor element comprise a porous material.

6. 6. The article of claim 5, wherein the porous material has a porosity of 45% to 80%, preferably 55% to 70%.

7. The article of claim 1 , comprising an airflow path extending along a central longitudinal axis of the hollow tubular proximal region of the susceptor element.

8. The article of claim 1 , comprising one or more air inlets located proximal to the closed distal end.

9. 9. The article of claim 8, wherein the size, number and arrangement of the one or more air inlets are configured to predetermine an overall resistance to withdrawal of the article, and wherein the one or more air inlets are arranged such that the overall resistance to withdrawal of the article is in the range of 50 to 200 mm of water column, preferably 100 to 160 mm of water column, more preferably 120 to 140 mm of water column.

10. The article of claim 1 , comprising a hollow tubular liquid reservoir coaxially surrounding said core element.

11. The article of claim 10 , wherein the hollow tubular liquid storage portion comprises a high retention material adjacent a sidewall of the core element.

12. The article of claim 11 , comprising a porous wall element provided at an interface between the high retention material and the core element.

13. 2. The article of claim 1, wherein the article has a cylindrical shape and an outer diameter of the article is between 5 millimeters and 10 millimeters, preferably between 6 millimeters and 8 millimeters.

14. The article of claim 1 , wherein the closed distal end is fluid impermeable.

15. 1. An aerosol generating system comprising: The article of claim 1; an aerosol generating device including a heating chamber for inserting at least a portion of the article, and an inductor coil at least partially surrounding the heating chamber for inductively heating the article.

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