Cartridge for an aerosol-generating system

Abstract

A cartridge for use in an aerosol generation system is described. The cartridge comprises a liquid storage unit including a housing (24) for holding a liquid aerosol forming material, wherein the liquid storage unit comprises at least two parts that are fluidly connected to each other. A first part (32) of the liquid storage unit comprises a heater assembly (46), a first capillary material (36) provided in contact with the heater assembly, and a second capillary material (38) in contact with the first capillary material and separated from the heater assembly by the first capillary material. A second part (34) of the liquid storage unit comprises a container, such as a tank, for holding the aerosol forming material in liquid form and supplying the liquid to the second capillary material.

Description

Technology Field

[0001] The present invention relates to an aerosol generating system. In particular, the present invention relates to a portable aerosol generating system, for example, an electric smoking system. Aspects of the present invention relate to a cartridge for an aerosol generating system, particularly an electric smoking system. Background Technology

[0002] One type of aerosol generating system is an electric smoking system. A portable electric smoking system is known, comprising a device section including a battery and control electronics, and a cartridge section including a supply section of aerosol-forming material and an electric evaporator. A cartridge containing both the supply section of aerosol-forming material and the evaporator is sometimes referred to as a “cartomizer.” The evaporator typically includes a coil of heater wire wound around an elongate wick soaked in a liquid aerosol-forming material. A capillary material soaked in the aerosol-forming material supplies the liquid to the wick. The cartridge section typically includes a mouthpiece in addition to the supply section of aerosol-forming material and the electric evaporator, and the user inhales through the mouthpiece to draw the aerosol into their mouth.

[0003] In some types of electrically operated aerosol generators, a reservoir of the aerosol-forming liquid is provided within a tank. When used in an aerosol generation system, the liquid is transferred from the tank by capillary action to the wick of a coil wick heater assembly where the liquid evaporates. When the user inhales through the mouthpiece, an airflow flows over the heater assembly, and the generated aerosol is inhaled by the user.

[0004] The problem with such tank devices is that the system stops generating aerosols when the device is maintained at an angle where the liquid aerosol generating material inside the tank does not come into contact with the capillary system. Additionally, these systems may be prone to leakage, for example, if liquid from the tank overflows the core or leaks through the airflow path.

[0005] In other systems, the liquid storage portion of the cartridge is filled with a capillary medium. The liquid aerosol generating material is retained within the capillary material and delivered to the wick. According to this system, the aforementioned problems with the retention angle and the risk of leakage can be reduced. However, some residual liquid remains within the capillary material after use, leading to waste. Additionally, due to the decreasing saturation of the capillary medium during use, there may be inconsistencies in puff delivery within this system, making it impossible to provide a consistent, high-quality smoking experience. The problem to be solved

[0006] It would be desirable to have a cartridge that maintains or improves the aerosol generation performance of an aerosol generation system in which the cartridge is used, while avoiding one or more of the aforementioned or other disadvantages, for example, while avoiding waste of the aerosol generating liquid. means of solving the problem

[0007] According to a first aspect of the present invention, a cartridge for use in an aerosol generating system, such as an electric aerosol generating system, is provided, comprising a liquid reservoir for holding a liquid aerosol forming substrate. The liquid reservoir comprises at least two portions that are in fluid communication with each other. A first portion of the liquid reservoir comprises a heater assembly, a first capillary material provided in contact with the heater assembly, and a second capillary material in contact with the first capillary material and spaced apart from the heater assembly by the first capillary material. A second portion of the liquid reservoir comprises a container arranged to hold the aerosol forming substrate in liquid form and, preferably, to supply liquid to the second capillary material. A second portion of the liquid reservoir may comprise a substantially empty tank suitable for holding the aerosol forming substrate in liquid form. Effects of the invention

[0008] The capillary material is preferably designed to hold a sufficient liquid substrate for several puffs. As the capillary material is positioned in contact with the heater, the heater is supplied with a sufficient amount of aerosol-generating liquid regardless of the holding angle of the aerosol-generating liquid. The remaining internal volume of the liquid reservoir does not contain the capillary material but represents an empty tank for storing the aerosol-generating liquid. Under normal handling conditions, the aerosol-generating medium, particularly the aerosol-generating smoking device, is transported between puffs, and the capillary material will regularly come into contact to reabsorb new aerosol-generating liquid.

[0009] Due to the reduced amount of capillary material used, the amount of residual liquid remaining in the capillary material after use is less than in conventional cartridges in which the entire liquid reservoir is filled with capillary material. Furthermore, in performance tests, the TPM (total paticulate matter) output of an aerosol generating smoking device equipped with the cartridge of the present invention was found to be at least comparable to the performance of aerosol generating smoking devices equipped with currently available cartridges in many cases. Brief explanation of the drawing

[0010] FIGS. 1a to 1d are schematic diagrams of a system including a cartridge according to one embodiment of the present invention; FIG. 2 shows a cartridge having a porous medium according to a first aspect of the present invention; FIG. 3 shows an exploded view of a cartridge similar to that shown in FIG. 2; FIG. 4 shows a cartridge having a single porous medium that is compressed by the shape of the porous material immediately upon insertion into a housing; FIG. 5 shows a cartridge having a single porous medium that is compressed by the shape of the inner surface of the housing immediately upon insertion into the housing; Figure 6 shows a capillary material wound into a cylindrical shape and equipped with a tube-shaped heater in the center. Specific details for implementing the invention

[0011] Preferably, the liquid volume of the capillary material is such that it can hold enough liquid for 30 to 40 puffs or more. A 3-second puff may contain about 1 mg to 4 mg of liquid, for example, 3 mg to 4 mg of liquid. Preferably, the volume of the capillary material is between about 30 mg and about 160 mg, preferably 90 mg to about 160 mg or more, preferably 100 mg to 150 mg, and 130 mg. If there are two layers constituting the capillary material, the volume of the first and second layers may be such that about 10 to 20 weight percent of the liquid volume is in the first layer. For example, if the volume of the capillary material is 30 puffs, the volume of the first layer may be about 5 puffs and the volume of the second layer may be about 25 puffs.

[0012] It is believed that the risk of leakage from the device is reduced by a capillary material having a capacity for multiple puffs, for example, 30 or more puffs, without being bound by any specific theory. If the capillary material is too small, during puffing, the liquid may be drawn directly from the storage tank through the capillary material and the heater without evaporating, leading to leakage. Additionally, by having a capacity of 90 mg or more, multiple puffs can be taken from the device even when the liquid in the storage tank is not in direct contact with the capillary material.

[0013] The heater assembly may be substantially flat without the need for any winding of heater wire around a capillary wick and may include electrically conductive filaments.

[0014] Electrically conductive filaments may be placed within a single plane. Planar heater assemblies can be easily handled during manufacturing and can provide a robust structure.

[0015] Electrically conductive filaments may define gaps between these filaments, and the gaps may have a width between 10 µm and 100 µm. The filaments cause capillary action within the gaps, so that liquid to be evaporated during use is drawn into the gaps, increasing the contact area between the susceptor element and the liquid.

[0016] The electrically conductive filaments may form a mesh of a size between 160 and 600 Mesh US (+ / - 10%) (i.e., 160 to 600 filaments / inch (+ / - 10%)). The width of the gaps is preferably between 75 µm and 25 µm. The percentage of the open area of ​​the mesh, which is the ratio of the area of ​​the gaps to the total area of ​​the mesh, is preferably between 25 and 56%. The mesh may be formed using various types of weave or lattice structures. Alternatively, the electrically conductive filaments consist of an array of filaments arranged parallel to each other.

[0017] Electrically conductive filaments may have a diameter between 10 µm and 100 µm, preferably between 8 µm and 50 µm, and more preferably between 8 µm and 39 µm. The filaments may have a circular cross-section or a flat cross-section. Heater filaments may be formed by etching a sheet material, for example, a foil. This may be particularly advantageous when the heater assembly comprises an array of parallel filaments. If the heater assembly comprises a mesh or fabric of filaments, the filaments may be formed individually and woven together.

[0018] As described with respect to the first aspect, the heater assembly may include at least one filament made of a first material and at least one filament made of a second material different from the first material.

[0019] The heater assembly may comprise an electrical insulating substrate in which filaments are supported, and the filaments extend across perforations formed within the substrate. The electrical insulating substrate may comprise any suitable material, preferably a material capable of withstanding high temperatures (over 300°C) and rapid temperature changes. An example of a suitable material is a polyimide film, e.g., Kapton®.

[0020] The heater assembly may include an electrically conductive contact portion in contact with a plurality of filaments. The electrically conductive contact portion may be provided between the housing of the liquid reservoir and an electrically insulating substrate. The electrically conductive contact portion may be provided between the filaments and the electrically insulating substrate. A perforation may be formed within the electrically insulating layer, and the cartridge may include two electrically conductive contact portions located on opposite sides of the perforation.

[0021] The capillary material is preferably a material that actively transfers liquid from one end of the material to the other. The capillary material is advantageously oriented within a housing to transfer liquid to a heater assembly.

[0022] The second capillary material may comprise a fibrous structure in which the fibers are generally oriented in the direction of liquid movement relative to the heater. The first capillary material may have less oriented fibers. For example, the first capillary material may have a felt structure.

[0023] The capillary material may have a fibrous or sponge-like structure. The capillary material preferably comprises a bundle of capillaries. For example, the capillary material may comprise a plurality of fibers, threads, or other microporous tubes. The fibers or threads may generally be aligned to deliver the liquid to the heater. Alternatively, the capillary material may comprise a sponge-like or foam-like material. The structure of the capillary material forms a plurality of small holes or tubes through which the liquid can be transported by capillary action. The capillary material may comprise any suitable material or a combination of materials. Examples of suitable materials include sponge or foam materials, ceramic or graphite-like materials in the form of fibers or calcined powder, foamed metal or plastic materials, and fibrous materials composed of spun or extruded fibers such as cellulose acetate, polyester, or combined polyolefin, polyethylene, tylene or polypropylene fibers, nylon fibers, or ceramics. The capillary material may have any suitable capillary action and porosity to be used with different liquid properties. Liquids possess physical properties including, but are not limited to, viscosity, surface tension, density, thermal conductivity, boiling point, and vapor pressure, and enable the liquid to be transported through a capillary device by capillary action.

[0024] The capillary material may be in contact with heaters, for example, electrically conductive filaments. The capillary material may extend into the gaps between said filaments. The heater assembly may draw a liquid aerosol-forming substrate into said gaps by capillary action. The capillary material may be in contact with the electrically conductive filaments over virtually the entire range of the perforation.

[0025] The housing may contain two or more different capillary materials, wherein the first capillary material in contact with the heater element has a higher thermal decomposition temperature, and the second capillary material in contact with the first capillary material but not with the heater element has a lower thermal decomposition temperature. The first capillary material effectively acts as a spacer separating the heater element from the second capillary material so that the second capillary material is not exposed to temperatures above its thermal decomposition temperature. As used herein, “thermal decomposition temperature” refers to the temperature at which a material begins to decompose and loses mass due to gas generation by the products. The second capillary material may advantageously occupy a larger volume than the first capillary material and may contain more aerosol-forming material than the first capillary material. The second capillary material may have superior wick performance than the first capillary material. The second capillary material may be less expensive than the first capillary material. The second capillary material may be polypropylene.

[0026] The first capillary material may be selected from the group consisting of Kevlar felt, ceramic paper, ceramic felt, carbon felt, cellulose acetate, hemp felt, PET / PBT sheet, cotton pad, porous ceramic disc, or porous metal disc.

[0027] Preferred materials include Kevlar felt, ceramic paper, ceramic felt, porous ceramic discs, or porous metal discs. The first capillary material may include glass fiber paper or felt. Preferably, the first capillary material does not contain substantially any organic material.

[0028] Preferably, the porosity of the first capillary material is less than that of the second capillary material. Preferably, the pore size of the first capillary material is smaller than that of the second capillary material. The pore size may be measured, for example, as the average pore size over an area of ​​the capillary material. In this way, it can be seen that the aerosol generating material is moved more efficiently to the heater. In a broad aspect of the invention, a cartridge is provided, said cartridge comprising a heater and a capillary material in contact with the heater to supply an aerosol generating material to the heater, wherein the porosity or pore size of the area of ​​the capillary material adjacent to the heater is smaller than the porosity or pore size of the area of ​​the capillary material far from the heater. Thus, a single material may be used, and, for example, has a gradient of pore size in one or more of its dimensions.

[0029] The first capillary material may have a fiber size / pore size between 0.1 and 50 µm, preferably between 0.5 and 10 µm, most preferably about 4 µm. The first capillary material has a density below 2 g / ml, preferably about 0.5 g / ml.

[0030] The second capillary material may be a so-called high retention material (HRM) selected from the group of polypropylene (PP), polyethylene (PE), polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), roll-type nonwoven fabric, or roll-type felt. Preferably, the second capillary material comprises a polymer material. The material may, for example, comprise a coating layer that reduces hydrophobicity.

[0031] The second capillary material may have a fiber size / pore size between 1 and 100 µm, preferably between 15 and 40 µm, most preferably about 25 µm. The second capillary material may have a density below 1 g / ml, preferably between 0.1 and 0.3 g / ml.

[0032] The first capillary material may separate the heater assembly from the second capillary material by a distance of at least 0.8 mm, for example, at least 1.5 mm, preferably between 0.8 mm and 2 mm, thereby providing a sufficient temperature drop across the first capillary material.

[0033] The first and second capillary materials may also be made of the same material and may be distinguished from one another only in that they exhibit different porosity or different capillary phenomena. For example, the first capillary material may be compressed such that its pore size or porosity is reduced and its capillary phenomenon is increased compared to the second capillary material, which may be used in an uncompressed or at least less compressed state.

[0034] In a preferred embodiment, the first and second materials consist of a single continuous element of the same base material. More preferably, the material is treated such that a gradient of pore size or porosity is obtained in a direction toward the heater element or opening, so that within the capillary material toward the heater element, the pore size or porosity decreases, for example, continuously.

[0035] Preferably, at least the first capillary material is compressed immediately upon insertion into the first part of the housing of the liquid reservoir, thereby reducing its effective pore size or porosity. For example, a single continuous element may have the shape of a truncated cone, wherein the diameter of the circular base of the truncated cone is larger than the inner diameter of the cylindrical housing of the liquid reservoir, while the diameter of the truncated apex of the cone substantially corresponds to the inner diameter of the cylindrical housing of the liquid reservoir. Upon insertion, the capillary material at the base of the cone is compressed more than the area of ​​the truncated apex. The more compressed material represents the first capillary material, and the less compressed material represents the second capillary material. A person skilled in the art will easily recognize that the resulting gradient of compression depends on the relative shapes selected for the capillary element and the housing of the liquid reservoir.

[0036] In a particularly preferred embodiment, the capillary element has a normal cylindrical shape having a circular cross-section and a predetermined diameter. The inner surface of the housing includes a tapered portion at the open end, so that the capillary material is compressed by this tapered portion immediately upon insertion of the capillary material into the housing. Preferably, the inner surface of the housing has a conical shape such that the inner diameter increases continuously from the open end toward the closed end of the cartridge.

[0037] The first capillary material and the second capillary material may include different regions of the same capillary material element. When placed within the housing, compression of the capillary material may cause the pore size or porosity of the capillary material to decrease or continuously decrease toward the heater assembly.

[0038] In another embodiment, the first and second capillary materials again consist of a single continuous piece of the same material. The capillary material may be a rectangular web of capillary material having a thickness of less than 50%, preferably about 25%, of the inner diameter of the cylindrical housing of the cartridge. The width of the web of capillary material corresponds to the perimeter of the housing. The web of capillary material may have any desired length, preferably about half the length of the housing of the cartridge. The web of capillary material is wound to form a cylindrical shape. By winding, the central part of the web is compressed to a higher degree than the outer part of the web, so that a gradient of pore size or porosity is obtained in the radial direction of the wound web of capillary material. An air channel is formed in the middle of the wound capillary material. A tubular fluid-permeable heater element is provided in the air channel so that the heater comes into direct contact with the inner surface of the wound capillary material. When winding the capillary material, the portion of the material closer to the central axis of the cylinder is compressed more than the material within the portion located radially outward of the capillary material. Consequently, a gradient in pore size is obtained, wherein the pore size of the capillary material decreases continuously from the interior of the capillary material toward the heater element. The capillary material is fluidly connected to a liquid reservoir, where the liquid reservoir is provided in a portion of the housing not occupied by the capillary material. A partition is provided inside the housing to ensure that the liquid material does not communicate directly with the airflow channel.

[0039] The web of capillary material may also include multiple layers of capillary material, allowing it to be designed in any desired way that is most suitable for a given aerosol generation system based on the liquid retention properties of the capillary material.

[0040] In a particularly preferred embodiment, the heater element is wound together with the capillary material so that a combined capillary material containing a heating element having a radial gradient is obtained in only one manufacturing step.

[0041] A liquid storage portion may be located on a first surface of electrically conductive filaments, and an airflow channel may be located on a surface opposite to the liquid storage portion of the electrically conductive filaments, so that an airflow passing through the electrically conductive filaments entrains an evaporated liquid aerosol-forming substrate.

[0042] Preferably, the aerosol generating system comprises a housing. Preferably, the housing is elongated. The housing may comprise any suitable material or a combination of materials. Examples of suitable materials include metals, alloys, plastics, or composite materials comprising one or more of such materials, or thermoplastic materials suitable for application in food or pharmaceuticals, such as polypropylene, polyetherketone (PEEK), and polyethylene. Preferably, the material is lightweight and non-brittle. The material may comprise PET, PBT, or PPS.

[0043] Preferably, the aerosol generating system is portable. The aerosol generating system may have a size comparable to a conventional cigar or cigarette. The smoking system may have a total length between approximately 30 mm and approximately 150 mm. The smoking system may have an outer diameter between approximately 5 mm and approximately 30 mm.

[0044] An aerosol-forming substrate is a substrate capable of releasing volatile compounds capable of forming an aerosol. Volatile compounds may also be released by heating the aerosol-forming substrate.

[0045] The aerosol-forming substrate may include plant-based materials. The aerosol-forming substrate may include tobacco. The aerosol-forming substrate may include a tobacco-containing material containing volatile tobacco flavor compounds that are released from the aerosol-forming substrate upon heating. Alternatively, the aerosol-forming substrate may include a non-tobacco-containing material. The aerosol-forming substrate may include homogenized plant-based materials. The aerosol-forming substrate may include homogenized tobacco materials. The aerosol-forming substrate may include at least one aerosol-forming agent. The aerosol-forming substrate may include materials such as other additives and flavoring agents.

[0046] Preferably, the liquid reservoir includes an opening, and the heater assembly extends across the opening of the housing. The heater assembly may include an electrical insulating substrate in which the heater element is supported. The electrical insulating substrate may include any suitable material, preferably a material capable of withstanding high temperatures (over 300°C) and rapid temperature changes. An example of a suitable material is a polyimide film, e.g., Kapton®. The electrical insulating substrate has perforations formed therein, and the heater element extends across the perforations. The heater assembly may include electrical contacts connected to electrically conductive filaments.

[0047] According to a second aspect of the present invention, a cartridge for use in an aerosol generating system, for example, an electric aerosol generating system, is provided, having a liquid reservoir comprising a housing for holding a liquid aerosol forming substrate, wherein the liquid reservoir comprises at least two portions fluidly communicating with each other. A first portion of the liquid reservoir comprises a first capillary material provided near an opening of the housing, and a second capillary material in contact with the first capillary material and spaced apart from the opening by the first capillary material. A second portion of the liquid reservoir may be substantially empty and is suitable for holding the aerosol forming substrate in liquid form.

[0048] The cartridge preferably further includes a fluid-permeable heater assembly extending across an opening of the housing.

[0049] In embodiments of the present invention, the first portion of the liquid storage unit occupies less than 50% of the volume of the liquid storage unit, preferably between 10% and 30%, more preferably between 15% and 25%, and most preferably about 20%.

[0050] The capillary material extends across the entire cross-section of the first part of the liquid storage section, so that the liquid aerosol generating material does not flow directly into the opening of the heater assembly or cartridge.

[0051] According to another aspect of the present invention, an aerosol generating system comprising a cartridge according to the present invention is provided.

[0052] The above system may further include an electric circuit connected to a heater assembly and an electric power source, and the electric circuit is configured to monitor the electrical resistance of the heater assembly or one or more filaments of the heater assembly and to control the power supply to the heater assembly according to the electrical resistance of the heater assembly or one or more filaments.

[0053] The electrical circuit may include a microprocessor, which may be a programmable microprocessor. The electrical circuit may further include electronic components. The electrical circuit may be configured to regulate the power supply to the heater assembly. Power may be supplied to the heater assembly to continuously accompany the activation of the system, or it may be supplied intermittently, for example, on a per-puff basis. Power may also be supplied to the heater assembly in the form of current pulses.

[0054] The above system advantageously includes a power supply, typically a battery, inside the main body of the housing. Alternatively, the power supply may be another type of charge storage device, such as a capacitor. The power supply may require recharging and may have a capacity that allows for the storage of energy sufficient for one or more smoking experiences; for example, the power supply may have a capacity sufficient to allow for the continuous generation of aerosols for a period of about 6 minutes, or twice 6 minutes, corresponding to the usual time taken to smoke a regular cigarette. In another embodiment, the power supply may have a capacity sufficient to allow for the individual activation of a predetermined number of puffs or heater assemblies.

[0055] Preferably, the aerosol generating system comprises a housing. Preferably, the housing is elongated. The housing may comprise any suitable material or a combination of materials. Examples of suitable materials include metals, alloys, plastics, or composite materials comprising one or more of such materials, or thermoplastic materials suitable for application in food or pharmaceuticals, such as polypropylene, polyetherketone (PEEK), and polyethylene. Preferably, the material is lightweight and non-brittle.

[0056] Preferably, the aerosol generating system is portable. The aerosol generating system may have a size comparable to a conventional cigar or cigarette. The smoking system may have a total length between approximately 30 mm and approximately 150 mm. The smoking system may have an outer diameter between approximately 5 mm and approximately 30 mm.

[0057] An aerosol-forming substrate is a substrate capable of releasing volatile compounds capable of forming an aerosol. Volatile compounds may also be released by heating the aerosol-forming substrate.

[0058] The aerosol-forming substrate may include plant-based materials. The aerosol-forming substrate may include tobacco. The aerosol-forming substrate may include a tobacco-containing material containing volatile tobacco flavor compounds that are released from the aerosol-forming substrate upon heating. Alternatively, the aerosol-forming substrate may include a non-tobacco-containing material. The aerosol-forming substrate may include homogenized plant-based materials. The aerosol-forming substrate may include homogenized tobacco materials. The aerosol-forming substrate may include at least one aerosol-forming agent. The aerosol-forming substrate may include materials such as other additives and flavoring agents.

[0059] Preferably, the system includes a mouthpiece, wherein a cartridge is inserted into the system in an orientation where the opening of the cartridge is located away from the mouthpiece.

[0060] In another preferred embodiment, the cartridge is inserted into the system with an orientation in which the opening of the cartridge is positioned toward the mouthpiece. Depending on the usage environment, one of these orientations of the cartridge may provide superior performance compared to the others.

[0061] According to another aspect of the present invention, a cartridge for use in an aerosol generating system is provided, said cartridge comprises a liquid reservoir including a housing for holding a liquid aerosol forming substrate, said liquid reservoir comprises a heater assembly and a capillary material provided in contact with said heater assembly, wherein the average porosity or pore size of the region of the capillary material adjacent to the heater assembly is smaller than the average porosity or pore size of the region of the capillary material far from the heater assembly. A portion of the capillary material within said region may be compressed to reduce its porosity and pore size. The liquid reservoir may comprise at least two portions fluidly communicating with each other, said first portion of the liquid reservoir comprises a capillary material, and said second portion of the liquid reservoir comprises a container for holding the aerosol forming substrate in liquid form and supplying the liquid to a region of higher porosity or pore size of the capillary material.

[0062] The present invention also relates to a method for manufacturing a cartridge for use in an electrically operated aerosol generating system, the method comprising the steps of: providing a liquid storage unit comprising a housing having a first portion and a second portion; providing a heater assembly; placing a first capillary material within the first portion of the housing of the liquid storage unit so that the first capillary material is in direct contact with the heater assembly; and placing a second capillary material within the first portion of the housing of the liquid storage unit so that the second capillary material is in contact with the first capillary material and is separated from the heater assembly by the first capillary material. The second portion of the liquid storage unit is substantially empty and suitable for holding an aerosol forming material in liquid form.

[0063] Preferably, the first capillary material is compressed during or before insertion into the housing so that its pore size or porosity is reduced compared to its pore size or porosity in the relaxed state.

[0064] One aspect of the present invention further provides a method for manufacturing a cartridge for use in an aerosol generating system, the method comprising the steps of providing a liquid storage unit including a housing, providing a heater assembly, and placing a capillary material within the housing of the liquid storage unit so that the capillary material is in direct contact with the heater assembly, wherein the method comprises the step of compressing a portion of the capillary material during or before placement within the housing so as to reduce the porosity or pore size of the portion of the capillary material.

[0065] The present invention also provides an aerosol generating system as described herein, which is an electrically operated smoking system.

[0066] The term “substantially flat” filament array refers to a filament array that is preferably in the form of a substantially two-dimensional topological manifold. Thus, a substantially flat filament array extends two dimensions along the surface rather than substantially in a third dimension. In particular, the dimensions of a substantially flat filament array that is two dimensions within the surface are at least five times larger than the third dimension normal to the surface. An example of a substantially flat filament array is a structure between two substantially parallel surfaces, where the distance between these two surfaces is substantially shorter than the extension within the surfaces. In some embodiments, the substantially flat filament array is planar. In other embodiments, the substantially flat filament array is curved along one or more dimensions and forms, for example, a dome shape or a bridge shape.

[0067] The term "filament" preferably refers to an electrical path arranged between two electrical contacts. The filament may be branched or split into several paths or filaments, or may converge from several electrical paths into a single path. The filament may have a circular, square, flat, or any other cross-sectional shape. The filament may be arranged in a straight or curved manner.

[0068] The term "filament array" preferably refers to an array of one or more preferably multiple filaments. The filament array may be, for example, an array of filaments arranged parallel to one another. Preferably, the filaments may form a mesh. The mesh may be a fabric or a nonwoven fabric.

[0069] It will be understood that, where appropriate, features of one aspect of the present invention may be provided in connection with other aspects of the present invention in any suitable combination.

[0070] The present invention will be further described for illustrative purposes only with reference to the accompanying drawings.

[0071] FIGS. 1a through 1d are schematic diagrams of an aerosol generating system including a cartridge according to one embodiment of the present invention. FIG. 1a is a schematic diagram of an aerosol generating device (10) and a separable cartridge (20), which together form an aerosol generating system. In this example, the aerosol generating system is an electrically operated smoking system.

[0072] The cartridge (20) contains an aerosol-forming material and is configured to be received within a cavity (18) inside the device. The cartridge (20) must be replaceable by the user when the aerosol-forming material provided in the cartridge is depleted. FIG. 1a shows the cartridge (20) immediately before insertion into the device, and arrow 1 in FIG. 1a shows the direction of insertion of the cartridge.

[0073] The aerosol generating device (10) is portable and has a size comparable to a conventional cigar or cigarette. The device (10) includes a main body (11) and a mouthpiece (12). The main body (11) includes a battery (14), for example, a lithium iron phosphate battery, a control electronic device (16), and a cavity (18). The mouthpiece (12) is connected to the main body (11) by a hinged connection (21) and can move between an open position as shown in FIGS. 1a to 1c and a closed position as shown in FIG. 1d. The mouthpiece (12) is positioned in an open position to allow insertion and removal of a cartridge (20), and is positioned in a closed position when the system is used to generate an aerosol, as described below. The mouthpiece includes a plurality of air inlet (13) and outlet (15). When in use, the user sucks or puffs over the outlet to draw air from the air inlet (13) through the mouthpiece to the outlet (15), and then draws it into the user's mouth or lungs. Internal baffles (17) are provided to force air flowing through the cartridge and the mouthpiece (12), as described below.

[0074] The cavity (18) has a circular cross-section and is sized to accommodate the housing (24) of the cartridge (20). Electrical connection portions (19) are provided on the sides of the cavity (18) to provide electrical connection between the control electronic device (16) and the corresponding electrical contact portions on the battery (14) and the cartridge (20).

[0075] FIG. 1b shows the system of FIG. 1a with the cartridge inserted into the cavity (118) and the cover (26) removed. In this position, the electrical connections are maintained with respect to the electrical contacts on the cartridge, as described below.

[0076] FIG. 1c shows the system of FIG. 1b in which the cover (26) is completely removed and the mouthpiece part (12) is moved to a sealed position.

[0077] FIG. 1d shows the system of FIG. 1c in which the mouthpiece portion (12) is in a closed position. The mouthpiece portion (12) is held in a closed position by a clasp mechanism. The mouthpiece portion (12) in the closed position is electrically in contact with the electrical connection portions (19) to hold the cartridge, so that a good electrical connection is maintained during use regardless of the orientation of the system. The mouthpiece portion (12) may include an annular elastomer element that is engaged with the surface of the cartridge and is compressed between the rigid mouthpiece housing element and the cartridge when the mouthpiece portion (12) is in a closed position. This ensures that a good electrical connection is maintained despite manufacturing tolerances.

[0078] Of course, other mechanisms to maintain a good electrical connection between the cartridge and the device may be used alternatively or additionally. For example, the housing (24) of the cartridge (20) may be provided with a thread or groove (not shown) that engages with a corresponding groove or thread (not shown) formed on the wall of the cavity (18). The screw connection between the cartridge and the device can be used to ensure accurate rotational alignment as well as to hold the cavity within the cavity and ensure a good electrical connection. The screw connection may be extended for only less than half a rotation of the cartridge, or it may be extended for several rotations. Alternatively, or additionally, the electrical connection portions (19) may be deflected in contact with the contact portions on the cartridge.

[0079] Other cartridge designs comprising the arrangement of capillary material according to the present invention may now be devised by those skilled in the art. For example, the cartridge may include a mouthpiece portion, may include one or more heater assemblies, and may have any desired shape. Additionally, the heater assembly according to the present invention may be used in systems of a different type from those already described, for example, humidifiers, air purifiers, and other aerosol generating systems.

[0080] The exemplary embodiments described above are merely examples and are not limiting. From the perspective of the exemplary embodiments described above, other embodiments consistent with the exemplary embodiments will now be apparent to those skilled in the art.

[0081] The cartridge illustrated in FIG. 2 includes a housing (24) made of polypropylene having two portions of liquid storage. The first portion (32) of the liquid storage includes a first capillary material (36) and a second capillary material (38). The second portion (34) of the liquid storage is an empty tank that can be filled or partially filled with a liquid aerosol generating material.

[0082] A ceramic substrate (42) is provided at the upper end of the cartridge. The substrate (24) defines an opening (44) and has electrical contacts (not shown) on its opposite sides. A heater element (46) is connected to the electrical contacts of the substrate (32) and extends over the opening (44) defined by the substrate.

[0083] Both the first capillary material (36) and the second capillary material (38) possess a liquid aerosol-forming substrate. The first capillary material (16), which is in direct contact with the heater element (46), has a higher thermal decomposition temperature (at least 160°C, e.g., approximately 250°C) than the second capillary material (38). The first capillary material (36) effectively acts as a spacer separating the heater element (46) from the second capillary material (38), so that the second capillary material (38) is not exposed to temperatures above its thermal decomposition temperature. The thermal gradient across the first capillary material (36) causes the second capillary material (38) to be exposed to temperatures below its thermal decomposition temperature. The second capillary material (38) may be selected to have superior wicking performance than the first capillary material (36), may hold more liquid per unit volume than the first capillary material (36), and may be less expensive than the first capillary material (36). In this embodiment, the first capillary material (36) is a heat-resistant element, for example, fiberglass or a fiberglass-containing element, and the second capillary material (38) is a polymer, for example, high-density polyethylene (HDPE) or polyethylene terephthalate (PET).

[0084] FIG. 3 is an exploded view of a cartridge similar to the cartridge of FIG. 2. The cartridge comprises a roughly circular cylindrical housing (24) comprising a first portion (32) and a second portion (34). The first portion of the housing (24) comprises first and second capillary materials (36, 38) soaked in a liquid aerosol generating substrate. In this example, the aerosol forming substrate comprises 39 wt% glycerin, 39 wt% propylene glycol, 20 wt% water and fragrance, and 2 wt% nicotine. Here, the capillary material is a material that actively transfers liquid from one end to the other and may be made of any suitable material. In this example, it is formed of polyester.

[0085] The housing (24) has an open end to which the heater assembly is fixed. The heater assembly comprises a substrate (42) having a perforation (44) formed therein, a pair of electrical contacts (48) fixed to the substrate (42) and spaced apart from each other by a gap (40), and a resistive heater element (46) extending over the perforation (44) and fixed to the electrical contacts (48) on the opposite sides of the perforation (44).

[0086] The heater assembly is covered by a removable cover (26). The cover (26) comprises a liquid-impermeable plastic sheet that is bonded to the heater assembly but can be easily peeled off. A tab is provided on the side of the cover so that the user can grasp it when peeling off the cover. Although bonding is described as a method for securing the impermeable plastic sheet to the heater assembly, it will now be obvious to those skilled in the art that other methods familiar to those skilled in the art, including heat sealing or ultrasonic welding, may also be used as long as the cover can be easily removed by the consumer.

[0087] FIG. 4 shows an embodiment in which the housing (24) has a normal cylindrical shape with a circular cross-section. The first and second capillary materials are made of the same material and are integrally formed as a single continuous piece of capillary material (60) having the shape of a truncated cone. The diameter of the truncated apex of the cone corresponds to the inner diameter of the cylindrical housing. The diameter of the base of the cone is twice the inner diameter of the cylindrical housing. The capillary material (60) is first inserted into the apex of the cylindrical housing (24) until the surface of the base of the cone is placed horizontally with the front of the cylindrical housing. Upon insertion, the capillary material (40) is compressed, and accordingly, due to the relative shape between the capillary material and the cylindrical housing, the compression of the capillary material (60) increases toward the end surface of the cylindrical housing. At the same time, the pore size or porosity of the capillary material is reduced such that the pore size or porosity of the capillary material near the end surface of the housing is smaller than the pore size or porosity of the capillary material located at the center of the cylindrical housing. At the open end of the cylindrical housing on the right side of FIG. 4, a seal is provided so that the interior of the cylindrical housing forms a tank reservoir for holding a liquid aerosol generating material. At the other end, a heater assembly as shown in FIG. 2 and FIG. 3 may be provided.

[0088] FIG. 5 shows an alternative embodiment having an effect similar to the embodiment illustrated in FIG. 4. In this case, the inner surface of the housing is provided with a conical shape so that the interior tapers toward one end of the housing (24). Here, the inner diameter of the housing (24) on the left side of FIG. 5 is half the inner diameter of the housing (24) on the right side. Again, the first and second capillary materials are made of the same material and are integrally formed as a single continuous piece of capillary material (60). The piece of capillary material (60) has a normal cylindrical shape with a circular cross-section. The diameter of the cylindrical piece of capillary material (60) corresponds to the inner diameter of the housing (24) on the right side of FIG. 5. The capillary material (60) is inserted into the housing (24) until the end surface of the capillary material (60) is positioned horizontally with the front surface of the smaller diameter of the cylindrical housing, i.e., the end surface on the left side of the housing (24). Upon insertion, the capillary material (60) is compressed again, and accordingly, due to the relative shape of the capillary material and the cylindrical housing, the compression of the capillary material (60) is increased toward the end surface on the left side of the cylindrical housing (24). At the same time, the pore size or porosity of the capillary is reduced so that the pore size or porosity of the capillary material (60) near the end surface of the housing is smaller than the pore size or porosity of the capillary material (60) located at the center of the cylindrical housing. Again, the open end of the cylindrical housing on the right side of FIG. 5 is provided with a seal so that the interior of the cylindrical housing forms a tank reservoir for holding a liquid aerosol generating material. A heater assembly as shown in FIGS. 2 and FIGS. 3 may be provided on the other end surface of the housing.

[0089] FIG. 6 illustrates another embodiment in which only the capillary material (50) to be used in the cylindrical housing is shown. The first and second capillary materials are again formed from a single continuous piece (50) of the same material. The capillary material is a rectangular web of capillary material having a thickness of about 25% of the inner diameter of the cylindrical housing of the cartridge. The width of the web of capillary material corresponds to the circumference of the housing. The length of the web of capillary material is approximately half the length of the housing of the cartridge. The web of capillary material is wound to form a cylindrical shape. An air channel (52) is formed in the middle of the wound capillary material. A tubular fluid-permeable heater element (54) is provided in the air channel (52) so that the heater (54) comes into direct contact with the inner surface (56) of the wound capillary material (50). When winding the capillary material, the portion of material (50a) closer to the central axis of the cylinder is compressed more than the portion of material (50b) located radially outside the capillary material. Thus, a gradient of pore size or porosity is obtained again, where the pore size or porosity of the capillary material (50) is continuously reduced in the direction from inside the capillary material toward the heater element (54). The capillary material is fluidly connected to a liquid reservoir (not shown), where the liquid reservoir is provided in a portion of the housing not occupied by the capillary material. A partition is provided inside the housing to ensure that the liquid material does not communicate directly with the airflow channel (52).

[0090] It will be understood that it is possible to obtain capillary materials having different pore sizes or porosities in different regions using different methods and configurations. In each embodiment, a region with a smaller pore size or porosity is located at one end of the capillary material. Subsequently, the region with the smaller pore size and porosity is located at the heater. Subsequently, the gradient of the pore size or porosity enhances capillary action within the material, thereby drawing the aerosol generating substrate liquid into the heater. Explanation of the symbols

[0091] 10: Aerosol generator 11: Main body 12: Mouthpiece section 13: Air inlet 14: Battery 15: Outflow section 16: Electronic devices 17: Internal baffle 18,118: Common 19: Connection part 20: Cartridge 21: Connection part 24: Housing 26: Cover 32: Part 1 34: Part 2 16, 36: First capillary substance 38: Second capillary substance 32, 42: Record 40: Gap 40, 50, 60: Capillary material 44: Opening, Perforation 46: Heater element 48: Electrical contact 50: Continuous piece 50a: Material part 50b: Material within a part 52: Channel 54: Heater element 56: Internal surface

Claims

Claim 1 A cartridge for use in an aerosol generating system, wherein the cartridge comprises a liquid storage portion, the liquid storage portion comprises: - a housing, wherein an airflow channel is provided within the housing; - a liquid reservoir comprising a housing for holding a liquid aerosol forming material, wherein a partition is provided between the airflow channel and the liquid reservoir; - a heater assembly disposed within the airflow channel; - a first capillary material provided in contact with the heater assembly; - a second capillary material in contact with the first capillary material and the liquid reservoir, and spaced apart from the heater assembly by the first capillary material, wherein the average pore size or porosity of the first capillary material is smaller than the average pore size or porosity of the second capillary material, the first capillary material has a fiber size or pore size of 0.1 to 10 μm, and the second capillary material has a fiber size or pore size of 15 to 40 μm. Claim 2 A cartridge according to claim 1, wherein the first capillary material and the second capillary material comprise different regions of the same capillary material element. Claim 3 In paragraph 2, the above-mentioned capillary material is a cartridge, which is a rectangular web of capillary material. Claim 4 In paragraph 3, the web of the capillary material has a thickness of 25% of the inner diameter of the housing, in a cartridge. Claim 5 In paragraph 3, a cartridge in which the length of the web of the capillary material is half the length of the housing of the cartridge. Claim 6 In paragraph 3, the web of the capillary material is wound to form a cylindrical shape, a cartridge. Claim 7 In paragraph 2, the portion of the capillary material closer to the heater assembly is more compressed than the capillary material within the portion located radially outside the capillary material, in a cartridge. Claim 8 In paragraph 2, the cartridge, wherein the pore size or porosity of the capillary material is continuously reduced in the direction from the inside of the capillary material toward the heater assembly. Claim 9 In paragraph 1, the heater assembly is a cartridge, which is a tubular fluid-permeable heater element. Claim 10 In paragraph 1, the housing is cylindrical, the cartridge. Claim 11 In paragraph 1, the liquid storage tank is provided in a part of the housing not occupied by a capillary material, a cartridge. Claim 12 In claim 1, the first capillary material is a cartridge having a density of less than 2 g / ml. Claim 13 In claim 1, the second capillary material is a cartridge having a density of less than 1 g / ml. Claim 14 A method for manufacturing a cartridge for use in an aerosol generation system, comprising: a step of providing a liquid storage portion including a housing, wherein an airflow channel is provided within the housing; a step of providing a liquid reservoir including a housing for holding a liquid aerosol forming material, wherein a partition is provided between the airflow channel and the liquid reservoir; a step of placing a heater assembly within the airflow channel; a step of providing a first capillary material in contact with the heater assembly; a step of placing a second capillary material in contact with the first capillary material and the liquid reservoir, and placing the second capillary material spaced apart from the heater assembly by the first capillary material, wherein the average pore size or porosity of the first capillary material is smaller than the average pore size or porosity of the second capillary material, the first capillary material has a fiber size or pore size of 0.1 to 10 μm, and the second capillary material has a fiber size or pore size of 15 to 40 μm. Claim 15 An aerosol generating system comprising a cartridge according to any one of claims 1 to 13. Claim 16 delete Claim 17 delete Claim 18 delete Claim 19 delete Claim 20 delete Claim 21 delete Claim 22 delete Claim 23 delete Claim 24 delete

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