An aerosol-generating system having a heater assembly and a cartridge for an aerosol-generating system having a fluid permeable heater assembly

Abstract

A liquid reservoir (20) comprising a rigid housing (24) having a liquid aerosol forming substrate, wherein the housing has an opening; and a fluid permeable heater assembly (30) comprising a plurality of electrically conductive filaments, wherein the fluid permeable heater assembly is fixed to the housing and extends across the opening of the housing. By providing a heater assembly extending across the opening of the liquid reservoir, a rigid configuration that is relatively simple to manufacture is made possible. This arrangement allows for a large contact area between the heater assembly and the liquid aerosol forming substrate. The heater assembly can be substantially flat while enabling simple manufacturing.

Description

Technology Field

[0001] The present invention relates to an aerosol generating system comprising a heater assembly suitable for evaporating a liquid. In particular, the present invention relates to a portable aerosol generating system, such as 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 that comprises a device portion including a battery and control electronics, a cartridge portion including a supply portion of aerosol-forming material, and an electric evaporator. A cartridge comprising both the supply portion of aerosol-forming material and the evaporator is sometimes referred to as a "cartomizer." The evaporator typically comprises a coil of heater wire wound around a slender wick immersed in a liquid aerosol-forming material. The cartridge portion typically comprises not only the supply portion of aerosol-forming material and the electric evaporator, but also a mouthpiece that the user inhales to inhale the aerosol into the user's mouth during use.

[0003] However, this configuration has the disadvantage that cartridge production is considerably expensive. This is because manufacturing the wick and coil assembly is difficult. Additionally, the electrical contact between the heater wire coil and the electrical contact through which current is transmitted from the device must be handled with precision during manufacturing. Furthermore, these cartridges include a mouthpiece to protect the fragile wick and coil assembly during transport. However, including a complete and robust mouthpiece in each cartridge means that the material cost for each cartridge is high. Prior art literature

[65535] (Patent Document 1) US 20140000638 A1 The problem to be solved

[0004] It is desirable to provide a heater assembly suitable for an aerosol generating system, such as a portable electric smoking system, that is inexpensive to produce and robust. It is even more desirable to provide a heater assembly that is more efficient than conventional heater assemblies for aerosol generating systems. means of solving the problem

[0005] In one aspect, an aerosol generating system is provided, and the system is,

[0006] A liquid storage unit comprising a housing having a liquid aerosol forming substrate, wherein the housing has an opening; and

[0007] It includes a fluid-permeable heater assembly comprising a plurality of electrically conductive filaments, wherein the fluid-permeable electric heater assembly is fixed to a housing and extends across an opening of the housing. Brief explanation of the drawing

[0008] FIGS. 1a to 1d are schematic diagrams of a system including a cartridge according to one embodiment of the present invention; FIG. 2 is a schematic diagram of a clasp mechanism for the mouthpiece portion of the system of FIG. 1; FIG. 3 is an exploded view of the cartridges of FIG. 1a to 1d; FIG. 4 is an exploded view of an alternative cartridge for use in a system as illustrated in FIG. 1a to 1d; FIG. 5a is a bottom perspective view of the cartridge of FIG. 2; FIG. 5b is an upper perspective view of the cartridge of FIG. 2 with the cover removed; FIG. 6 is a detailed view of a heater assembly used in the cartridge illustrated in FIG. 2; FIG. 7 is a detailed view of an alternative heater assembly that can be used in the cartridge illustrated in FIG. 2; FIG. 8 is a detailed view of an additional alternative heater assembly that can be used in the cartridge illustrated in FIG. 2; FIG. 9 is a detailed view of another additional alternative heater assembly that can be used in the cartridge illustrated in FIG. 2; FIG. 10 is a detailed view of an alternative mechanism for making electrical contact between a device and a heater assembly; FIGS. 11a and FIGS. 11b illustrate several cartridge housing shapes that can be used to ensure accurate alignment of a cartridge in a device; FIG. 12a is a detailed view of the filaments of a heater illustrating the meniscus of the liquid aerosol-forming substrate between the filaments; FIG. 12b is a detailed view of the filaments of a heater, illustrating the meniscus of the liquid aerosol-forming substrate between the filaments and the capillary material extending between the filaments; FIGS. 13a, 13b, and 13c illustrate alternative methods for manufacturing a heater assembly according to the present invention; FIG. 14 illustrates an alternative design for a liquid reservoir including a heater assembly. FIGS. 15a and FIGS. 15b illustrate additional alternative embodiments of a liquid reservoir including a heater assembly. FIG. 16 illustrates an alternative embodiment of airflow and cartridge orientation with an aerosol generator. FIG. 17 illustrates a cross-section of a cartridge system including a high retention material and an air path through an HRM; FIG. 18 illustrates a cross-section of another cartridge system including a high retention material and an air path through a cartridge; FIG. 19 is an exploded view of the cartridge system of FIG. 18; FIG. 20 illustrates a cross-section of a cartridge system having a liquid and an air path through the liquid. Specific details for implementing the invention

[0009] By providing a heater assembly that extends across the opening of the liquid reservoir, a rigid configuration that is relatively simple to manufacture is made possible. This arrangement allows for a large contact area between the heater assembly and the liquid aerosol forming substrate. The housing may be a rigid housing. As used herein, “rigid housing” means a freestanding housing. The rigid housing of the liquid reservoir preferably provides mechanical support to the heater assembly. The heater assembly may be substantially flat while enabling simple manufacturing. As used herein, “substantially flat” means that it is initially formed in a single plane and is not wrapped around to fit a curved or other non-planar shape, but is otherwise fitted. Geometrically, the term “substantially flat” is used to refer to an electrically conductive filament array in which the electrically conductive filament array is in the form of a substantially two-dimensional phase manifold. Thus, a substantially flat electrically conductive filament structure extends in two dimensions along the surface substantially rather than in a third dimension. Specifically, the dimension of a substantially flat filament structure in two dimensions within a surface is at least five times greater than a third dimension normal to the surface. An example of a substantially flat filament structure is a structure between two substantially parallel virtual planes, and the distance between these two virtual planes is substantially smaller than the extension within the surfaces. In some embodiments, the substantially flat filament structure is flat. In other embodiments, the substantially flat filament structure is bent along one or more dimensions to form, for example, a dome shape or a bridge shape.

[0010] The term “filament” is used throughout the specification to refer to an electrical path arranged between two electrical contacts. The filament may be branched arbitrarily into multiple paths or filaments, or may converge from multiple electrical paths into a single path. The filament may be round, square, flat, or any other shape of cross-section. The filament may be arranged in a straight or curved shape.

[0011] The term “filament structure” is used throughout the specification to refer to a structure of a single filament or, preferably, a plurality of filaments. A filament structure 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.

[0012] Flat heater assemblies can be easily handled during manufacturing and provide a robust structure.

[0013] The system may include a device and a cartridge detachably coupled to the device, wherein a liquid reservoir and a heater assembly are provided in the cartridge and the device includes a power supply. The cartridge may be manufactured in a reliable and repeatable manner at a low cost. As used herein, a cartridge “detachably coupled” to the device means that the cartridge and the device can be connected and disconnected from each other without significantly damaging the device or the cartridge.

[0014] The above system may be an electric smoking system.

[0015] Electrically conductive filaments may be placed on a single plane. Planar heater assemblies can be easily handled during manufacturing and provide a robust structure.

[0016] Electrically conductive filaments may define gaps between these filaments, and the gaps may have a width between 10 µm and 100 µm. Preferably, the filaments cause capillary action within the gaps so that liquid to be evaporated during use is drawn into the gaps, thereby increasing the contact area between the heater assembly and the liquid.

[0017] The electrically conductive filaments may form a mesh with 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 one another.

[0018] Meshes and fabrics of electrically conductive filaments may also be characterized by their ability to retain liquid, as is well understood in the field of technology.

[0019] The 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 round cross-section or a flattened cross-section.

[0020] The area of ​​the mesh, array, or fabric of electrically conductive filaments may be small, preferably 25 mm 2The following allows it to be included in a portable system. The mesh, array, or fabric of electrically conductive filaments may be, for example, rectangular or have dimensions of 5 mm x 2 mm. Preferably, the mesh or array of electrically conductive filaments covers an area between 10% and 50% of the surface area of ​​the heater assembly. More preferably, the mesh or array of electrically conductive filaments covers an area between 15% and 25% of the surface area of ​​the heater assembly. 10% and 50% of the surface area, or 25 mm 2 The size of the mesh, array, or fabric of electrically conductive filaments is less than or equal to the size of the mesh, array, or fabric of electrically conductive filaments, while reducing the total amount of power required to heat the mesh, array, or fabric of electrically conductive filaments, and ensuring sufficient contact of the mesh, array, or fabric of electrically conductive filaments with the liquid provided to one or more capillary materials that must still volatilize.

[0021] Heater filaments may be formed by etching a sheet material such as 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. Alternatively, the heater filaments may be stamped from an electrically conductive foil, such as stainless steel, for example.

[0022] The filaments of the heater assembly may be formed from any material having suitable electrical properties. Suitable materials include, but are not limited to, doped ceramics, electrically "conductive" ceramics (e.g., molybdenum disilicide), carbon, graphite, metals, metal alloys, and semiconductors such as composites of ceramic and metallic materials. Such composites may include doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and metals from the platinum group. Examples of suitable metal alloys include stainless steel, Constantan, nickel-, cobalt-, chromium-, aluminum-, titanium-, zirconium-, hafnium-, niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese-, gold-, and iron-containing alloys, and superalloys based on nickel, iron, cobalt, and stainless steel, Timetal®, iron-aluminum alloys, and iron-manganese-aluminum alloys. Timetal® is a registered trademark of Titanium Metals Corporation. The filaments may be coated with one or more insulators. Preferred materials for electrically conductive filaments are 304, 316, 304L, and 316L stainless steels and graphite. Additionally, the electrically conductive filament structure may comprise a combination of the above materials. A combination of materials may be used to improve resistance control of a substantially flat filament structure. For example, materials with high resistivity may be combined with materials with low resistivity. This may be advantageous if one of the materials is more beneficial from other perspectives, such as cost, machinability, or other physical and chemical parameters. Advantageously, a substantially flat filament structure with increased resistance reduces parasitic losses. Advantageously, high-resistance heaters can utilize battery energy more efficiently.Battery energy is proportionally divided between the energy lost at the printed circuit substrate and contacts and the energy transferred to the electrically conductive filament structure. Therefore, the energy available in the heater's electrically conductive filament structure is higher than the resistance of the electrically conductive filament structure.

[0023] In an exemplary embodiment, a substantially flat filament structure can be manufactured from two types of metal wires formed into a wire mesh. In this embodiment, preferably, the high resistance wire is oriented in the direction of current flow, for example, a wire made of nickel-chromium alloy. Accordingly, in this embodiment, the low resistance wires are arranged substantially perpendicular to the high resistance wires. For example, the low resistance wires may be stainless steel wires. Advantageously, the relatively low resistance wires form a support for the high resistance wires. Additionally, the high resistance wires are typically less malleable than the stainless steel wires and therefore may not be easily manufactured into thin wires. Thus, in this advantageous embodiment of the invention, the relatively thick wires with high resistance are combined with thin stainless steel wires with low resistance, thereby adding the advantage that the thinner stainless steel wires improve the wettability of the substantially flat filament structure through increased capillary force.

[0024] Alternatively, the electrically conductive filament structure can be formed from carbon thread textile. Carbon thread textile has the advantage of being more cost-effective than metal heaters, which typically have high resistance. Additionally, carbon thread textile is typically more flexible than metal mesh. Another advantage is that contact between the carbon thread textile and a transport medium, such as a highly separated material, can be well preserved during the manufacture of the fluid-permeable heater assembly.

[0025] Reliable contact between a fluid-permeable heater assembly and a transport medium, such as a capillary transport medium made of fiber or porous ceramic material, improves the constant wettability of the fluid-permeable heater assembly. This advantageously reduces the risk of overheating of the electrically conductive filament structure and accidental thermal decomposition of the liquid.

[0026] The heater assembly may comprise an electrically insulating substrate on which filaments are supported. The electrically insulating substrate may comprise any suitable material, preferably a material capable of withstanding high temperatures (above 300°C) and rapid temperature changes. An example of a suitable material is a polyimide film such as Kapton®. An aperture may be formed in the electrically insulating substrate along with electrically conductive filaments extending across the aperture. The heater assembly may comprise an electrical contact connected to the electrically conductive filament. For example, the electrical contact may be bonded, welded, or mechanically clamped to the electrically conductive filament structure with an adhesive. Alternatively, the electrically conductive filament structure may be printed onto the electrically insulating substrate, for example, using metallic ink. In this configuration, preferably, the electrically insulating substrate is a porous material so that the electrically conductive filament structure can be directly attached to the surface of the porous material. Preferably, in this embodiment, the porosity of the substrate functions as an “opening” of the electrically insulating substrate through which liquid can be drawn toward the electrically conductive filament structure.

[0027] The electrical resistance of the mesh, array, or fabric of the electrically conductive filaments of the heater element is preferably between 0.3 Ohms and 4 Ohms. More preferably, the electrical resistance of the mesh, array, or fabric of the electrically conductive filaments is between 0.5 Ohms and 3 Ohms, and more preferably about 1 Ohm. The electrical resistance of the mesh, array, or fabric of the electrically conductive filaments is preferably at least one order of magnitude greater than the electrical resistance of the contact parts, and more preferably at least two orders of magnitude greater. This ensures that the heat generated by passing current through the heater element is confined to the mesh or array of the electrically conductive filaments. If the system is powered by a battery, it is advantageous to have low overall resistance in the heater element. A low-resistance, high-current system allows high power to be delivered to the heater element. This enables the heater element to rapidly heat the electrically conductive filaments to a desired temperature.

[0028] The first and second electrically conductive contacts may be directly fixed to the electrically conductive filaments. The contacts may be positioned between the electrically conductive filaments and an electrically insulating substrate. For example, the contacts may be formed from copper foil plated on the insulating substrate. Additionally, the contacts may bond more easily with the filaments than with the insulating substrate.

[0029] Alternatively, the first and second electrically conductive contacts may be integral with the electrically conductive filaments. For example, the heater element may be formed by etching a conductive sheet to provide a plurality of filaments between the two contacts.

[0030] The heater assembly may comprise at least one filament made of a first material and at least one filament made of a second material different from the first material. This may be advantageous for electrical or mechanical reasons. For example, one or more of the filaments may be formed of a material having a resistance that varies significantly with temperature, such as, for example, an iron-aluminum alloy. This allows the resistance scale of the filaments used to determine temperature changes or temperatures. This can be used in a puff detection system and can be used to control the heater temperature to maintain the heater temperature within a desired temperature range. Sudden changes in temperature may also be used as a means to detect changes in airflow passing through the heater assembly originating from the user puff of the system.

[0031] The housing of the liquid reservoir advantageously contains a capillary material. A capillary material is a material that actively transfers liquid from one end to another. The capillary material is advantageously oriented within the housing to transfer the liquid to the heater assembly.

[0032] The capillary material may have a fibrous or sponge-like structure. The capillary material preferably comprises bundles of capillaries. For example, the capillary material may comprise multiple 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 sponge-like or foam-like materials. The structure of the capillary material forms multiple small holes or tubes through which the liquid can be transported by capillary action. The capillary material may comprise any suitable material or 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.

[0033] The capillary material may be in contact with electrically conductive filaments. The capillary material may extend into the gaps between the filaments. The heater assembly may draw a liquid aerosol-forming substrate into the gaps by capillary action. The capillary material may be in contact with the electrically conductive filaments substantially throughout the entire opening. In one embodiment, the capillary material in contact with the electrically conductive filament structure may be a filament wick. Preferably, the filament wick has a first portion and a second portion, the first portion is positioned substantially perpendicular to the electrically conductive filament structure and reaches the liquid reservoir of the cartridge. Preferably, the second portion of the filament wick is positioned substantially parallel to the electrically conductive filament structure. Preferably, the filaments of the filament wick are continuous from the first portion of the filament wick to the second portion of the filament wick. This enables rapid transport of liquid toward the electrically conductive filament structure through the first part of the filament wick and, at the same time, rapid distribution across the electrically conductive filament structure through the second part of the filament wick. This advantageously enables continuous wetting of the entire electrically conductive filament structure. Continuous wetting can avoid overheating and prevent accidental decomposition of the liquid due to overheating.

[0034] Preferably, the electrically conductive filament structure comprises at least several filaments made of an alloy or coated with a film sensitive to the presence of a liquid, such as water. This enables the detection of wetting of the electrically conductive filament structure, for example, by connecting sensitive wires to a circuit that monitors the electrical resistance of the wires, and can prevent the heater from operating or reduce the current upon detection of a dry interface. This advantageously increases the safety of the aerosol generation system. In one embodiment, the filaments used to detect wetting are stainless steel wires coated with an indium nitride (InN) or aluminum oxide (Al2O3) film. When in use, a liquid, such as water, depletes electrons from the surface of these films and preserves the high electrical resistance of the film until the film surface dries out. Subsequently, the resistance drops rapidly. The drop in resistance is detected by a connected electronic circuit.

[0035] Advantageously, the heater assembly and the capillary material may have a size such that they have approximately the same area. As used herein, "approximately" means that the heater assembly may be between 0 and 15% larger than the capillary material. The shape of the heater assembly may also be similar to the shape of the capillary material so that the heater assembly and the capillary material substantially overlap. If the size and shape of the heater assembly and the capillary material are substantially similar, manufacturing can be simplified and the robustness of the manufacturing process can be improved. As described below, the capillary material may comprise two or more capillary materials comprising one or more layers of the capillary material in direct contact with a mesh, array, or fabric of electrically conductive filaments of the heater assembly to promote aerosol generation. The capillary material may comprise the material described herein.

[0036] At least one of the capillary materials may have a sufficient volume to ensure that a minimum amount of liquid is present in the capillary material to prevent “dry heating” which occurs when an insufficient amount of liquid is provided to the capillary material in contact with a mesh, array, or fabric of electrically conductive filaments. The minimum volume of the capillary material may be provided to allow between 20 and 40 puffs by a user. The average volume of liquid evaporated during a puff of length between 1 and 4 seconds is typically between 1 and 4 mg of liquid. Thus, dry heating can be prevented by providing at least one capillary material having a volume to hold between 20 and 160 mg of liquid containing a liquid-forming substrate.

[0037] The housing may contain two or more different capillary materials, wherein the first capillary material in contact with the heater element has a high thermal decomposition temperature, and the second capillary material in contact with the first capillary material but not with the heater element has a low 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 lose mass due to the generation of gaseous byproducts. The second capillary material may advantageously occupy a larger volume than the first capillary material and may possess more aerosol-forming substrates than the aerosol-forming substrates of the first capillary material. The second capillary material may have superior wicking performance than the first capillary material. The second capillary material may be cheaper than the first capillary material. The second capillary material may be polypropylene.

[0038] The first capillary material may be separated from the heater assembly by a distance of at least 1.5 mm, preferably between 1.5 mm and 2 mm, to provide a sufficient temperature drop across the first capillary material.

[0039] The liquid reservoir may be located in an airflow channel located on the first side of the electrically conductive filaments and on the opposite side of the electrically conductive filaments to the liquid reservoir, so that the airflow passing through the electrically conductive filaments entrains the evaporated liquid aerosol-forming substrate.

[0040] In addition to an electric heater assembly that is in contact with or located very close to the liquid transfer medium, the aerosol generation system may include at least one additional electric heater assembly capable of operating with the liquid reservoir. The additional electric heater assembly capable of operating with the liquid reservoir can increase the depletion of liquid from the liquid reservoir. This is particularly advantageous if the liquid reservoir contains a high-retention medium that stores the liquid. It is advantageous to use a high-retention medium to store liquid in the liquid reservoir. For example, using a high-retention medium reduces the risk of leakage. If failure or cracking occurs in the housing of a cartridge from which liquid has leaked, unnecessary contact with active electrical components and biological tissue may occur. However, as the liquid is guided to the surface of the high-retention medium by wetting forces, significant liquid loss may occur compared to a tank filled with free liquid if mechanical cracking occurs in the cartridge housing. However, as the high-retention medium inherently retains at least a portion of the liquid, this portion cannot be utilized for aerosolization. Advantageously, by providing an additional heater assembly, the ratio of liquid depletion of the liquid reservoir, that is, the ratio between the amount of liquid removed from the liquid reservoir and the amount of liquid that cannot be removed from the liquid reservoir, is increased.

[0041] Preferably, the additional electric heater assembly is located near areas of high-retention medium that may be less depleted by the primary electric heater assembly, for example, most areas of high-retention medium furthest from the first electric heater assembly. Preferably, the additional electric heater assembly is located on the lowest wall of the housing, that is, the wall opposite the electric heater assembly. Alternatively, or also, the additional electric heater assembly is located on a side wall of the housing.

[0042] Preferably, the additional electric heater assembly is controlled to be activated only when necessary, for example, when a decrease in liquid flow is detected. For example, the additional electric heater assembly may be activated when a decrease in the wettability of the first electric heater assembly is detected.

[0043] Alternatively, or also, the housing may be internally non-cylindrical, for example, conical in shape, wherein the wider portion of the internal non-cylindrical shape faces the electric heater assembly and the smaller portion of the internal non-cylindrical shape extends in the opposite direction. This can increase the relevance of gravity acting on the liquid to move the liquid toward the electric heater assembly, specifically to a location substantially horizontally oriented in the aerosol generation system. Horizontal orientation is an orientation in which the electric heater assembly is at substantially the same vertical height as the liquid reservoir. This horizontal orientation is typically present during the use of the aerosol generation system.

[0044] Alternatively, or also, a cartridge comprising an electric heater assembly and a housing is positioned in an aerosol generating system such that the electric heater assembly is positioned across an opening of the housing on the side of a liquid reservoir separated from the mouthpiece of the aerosol generating system. This may be advantageous for the flow path of the aerosol within the aerosol generating system. For example, in a vertical structure of the aerosol generating system, the mouthpiece is positioned at the top and the housing is positioned upside down, that is, the liquid is positioned above the electric heater assembly. In this embodiment, the capillary force moving the liquid toward the electric heater assembly is assisted by gravity instead of overcoming gravity.

[0045] Preferably, the housing comprises two elements, the first element being a cap and the second element being a tank, and the cap closes the tank. Preferably, according to the present invention, the cap comprises a heater assembly or is in close contact with the heater assembly. Preferably, the tank comprises a liquid in which a first capillary material is present or in which both the first and second capillary materials are present. Preferably, the cap material is made of a material having a high pyrolysis temperature, such as polyetheretherketone (PEEK) or Kapton®. Preferably, the cap has a sufficient size to space the tank from the heater assembly by a distance of at least 1.5 mm, preferably between 1.5 mm and 2 mm, to provide a sufficient temperature drop across the cap. Advantageously, in this embodiment, the tank material may be made of a more cost-effective material having a lower pyrolysis temperature, such as polyethylene or polypropylene.

[0046] An air inlet may be positioned, for example, in the main housing of the system. Ambient air is directed into the system, passes through a heating element in the base of the cartridge, and entrains the aerosol caused by heating the aerosol-forming material of the cartridge. Subsequently, the aerosol-containing air may be guided along the cartridge between the cartridge housing and the main housing to the downstream end of the system, where it is mixed with ambient air from an additional flow path (before or when reaching the downstream end).

[0047] The inlet opening of the second channel, positioned in the material area of ​​the cartridge housing, may also be provided in an alternative system in which a heating element is positioned near the end of the cartridge. The second flow path may pass outside the cartridge as well as through the cartridge. Subsequently, ambient air is introduced into the cartridge from the semi-open wall of the cartridge, passes through the cartridge, and leaves the cartridge by passing through the heating element positioned near the end of the cartridge. Accordingly, the ambient air may pass through the aerosol-forming substrate, or may pass through one or more channels positioned in the solid aerosol-forming substrate such that the ambient air does not pass through the substrate itself but passes only through channels next to the substrate.

[0048] To allow ambient air to enter the cartridge, at least one semi-open inlet is provided in the wall of the cartridge housing, preferably the wall on the side opposite the heating element, preferably the bottom wall. The semi-open inlet allows air to enter the cartridge but prevents any air or liquid from escaping the cartridge through the semi-open inlet. The semi-open inlet may be, for example, a semipermeable membrane that is permeable to air in one direction only and impermeable to both air and liquid in the opposite direction. The semi-open inlet may also be, for example, a one-way valve. Preferably, the semi-open inlet allows air to pass through the inlet only when certain conditions are met, for example, the volume of air passing through the valve or membrane or the minimum pressurization of the cartridge.

[0049] These unidirectional valves may be commercially available valves, such as those used in medical devices, for example, the LMS Mediflow unidirectional valve (across the membrane), the LMS SureFlow unidirectional valve, or the LMS check valve. Suitable membranes used in cartridges having an airflow through them are ventilated membranes, for example, as used in medical devices, such as Qosina Ref. 11066, i.e., hydrophobic filters or ventilated caps equipped with valves, such as those used in baby bottles. These valves and membranes may be manufactured from any material suitable for applications in electric heated smoking systems. Materials suitable for medical devices and FDA-approved materials may be used, for example, graphene, which has very high mechanical resistance and thermal stability over a wide temperature range. Preferably, the valves are manufactured from a soft, elastic material to support the inclusion of one or more valves within the walls of the container housing.

[0050] By allowing ambient air to pass through the substrate, the aerosolization of the aerosol-forming substrate is supported. During puffing, pressurization occurs in the cartridge, which can activate the semi-open inlet. Subsequently, ambient air passes through the cartridge, preferably through a high-retention or high-separation material (HRM) or liquid, crosses the heating element, and thereby generates and maintains aerosolization of the liquid when the heating element sufficiently heats the liquid. Additionally, due to the pressurization generated during puffing, the liquid supply of a transport material, such as a capillary material, to the heating element may be restricted. The ambient airflow through the cartridge can equalize the pressure difference within the cartridge and thereby support unhindered capillary action toward the heating element.

[0051] Additionally, a semi-opening inlet may also, or alternatively, be provided on one or more side walls of the cartridge housing. The semi-opening inlet of the side wall provides a lateral airflow into the cartridge toward the top of the opening of the cartridge housing where the heating element is placed. Preferably, the lateral airflow passes through an aerosol-forming substrate.

[0052] The system may further include an electric circuit connected to a heater assembly and an electric power supply, 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 that depends on 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 electrical 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 be supplied to the heater assembly in the form of pulses of current.

[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 sufficient energy 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 for a period of twice 6 minutes. In another embodiment, the power supply may have a capacity sufficient to allow for the activation of a predetermined number of puffs or individual 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] In a second aspect, a cartridge for use in an electric aerosol generating system is provided, and said cartridge,

[0060] A liquid storage unit comprising a housing having a liquid aerosol forming substrate, wherein the housing has an opening; and

[0061] It includes a fluid-permeable electric heater assembly comprising a plurality of electrically conductive filaments, wherein the fluid-permeable electric heater assembly extends across an opening in the housing of the liquid storage portion.

[0062] Cartridges with this configuration can be manufactured to be robust, reliable, and at a low cost. The heater assembly can be substantially flat without the need to wind any heater wire around the capillary wick.

[0063] Electrically conductive filaments may be placed on a single plane. Planar heater assemblies can be easily handled during manufacturing and provide a robust structure.

[0064] Electrically conductive filaments may define gaps between these filaments, and the gaps may have a width between 10 µm and 100 µm. Preferably, the filaments cause capillary action within the gaps so that liquid to be evaporated during use is drawn into the gaps, thereby increasing the contact area between the heater assembly and the liquid.

[0065] The electrically conductive filaments may form a mesh with 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 one another.

[0066] 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 rounded cross-section or a flattened cross-section. The heater filaments may be formed by etching a sheet material such as 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.

[0067] The area of ​​the mesh, array, or fabric of electrically conductive filaments may be small, preferably 25 mm 2 The following allows it to be included in a portable system. The mesh, array, or fabric of electrically conductive filaments may be, for example, rectangular and may have dimensions of 5 mm x 2 mm. Preferably, the mesh or array of electrically conductive filaments covers an area between 10% and 50% of the area of ​​the heater assembly. More preferably, the mesh or array of electrically conductive filaments covers an area between 15% and 25% of the area of ​​the heater assembly.

[0068] Electrically conductive filaments may contain any suitable electrically conductive material. Preferred materials for electrically conductive filaments are 304, 316, 304L, 316L stainless steel and graphite.

[0069] The electrical resistance of the mesh, array, or fabric of the electrically conductive filaments of the heater element is preferably between 0.3 and 4 Ohms. More preferably, the electrical resistance of the mesh, array, or fabric of the electrically conductive filaments is between 0.5 and 3 Ohms, and more preferably about 1 Ohm. The electrical resistance of the mesh, array, or fabric of the electrically conductive filaments is preferably at least one order of magnitude greater than the electrical resistance of the contact parts, and more preferably at least two orders of magnitude greater.

[0070] The housing of the liquid reservoir may contain a capillary material as described above in relation to the first aspect. The capillary material may be oriented within the housing to transfer the liquid to the heater assembly. The capillary material may be in contact with the heater assembly. The capillary material may extend into the gaps between the filaments.

[0071] As described above with respect to the first aspect, the housing may contain two or more different capillary materials, wherein the first capillary material in contact with the heater element has a high thermal decomposition temperature, and the second capillary material in contact with the first capillary material but not with the heater element has a low thermal decomposition temperature. To provide a sufficient temperature drop across the first capillary material, the heater assembly may be separated from the second capillary material by a distance of at least 1.5 mm, preferably between 1.5 mm and 2 mm.

[0072] As described above in relation to the first aspect, the heater assembly may comprise at least one filament made of a first material and at least one filament made of a second material different from the first material.

[0073] The heater assembly may comprise an electrical insulating substrate on which filaments are supported, said filaments extend across holes formed in said substrate. The electrical insulating substrate may comprise any suitable material, preferably a material capable of withstanding high temperatures (exceeding 300°C) and rapid temperature changes. An example of a suitable material is a polyimide film such as Kapton®.

[0074] The heater assembly may include an electrically conductive contact portion that contacts 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. An aperture may be formed on an electrically insulating layer, and the cartridge may include two electrically conductive contact portions located on opposite sides of the aperture.

[0075] Advantageously, the electrically conductive contact is accessible from the outside of the cartridge. The heater assembly may extend in a lateral plane, and the electrically conductive contact may extend laterally out of the housing of the liquid reservoir. Subsequently, the cartridge may be configured to be inserted into an aerosol generator in a direction orthogonal to the lateral plane so that the electrically conductive contact can come into contact with an electrical contact on the device.

[0076] The housing of the liquid reservoir may be substantially cylindrical, wherein the opening is at one end of the cylinder. The housing of the liquid reservoir may have a substantially circular cross-section.

[0077] The heater assembly is advantageously covered by a removable cover or seal before use. The cover or seal can protect the substrate from deterioration during storage and transport.

[0078] In a preferred embodiment, the cartridge does not include an electric power source.

[0079] In a third aspect, a method for manufacturing a cartridge for use in an electric aerosol generating system is provided, and the method comprises:

[0080] A step of providing a liquid storage unit including a housing having an opening;

[0081] A step of filling a liquid storage unit with an aerosol-forming substrate; and

[0082] The method includes the step of fixing a fluid-permeable heater assembly comprising a plurality of electrically conductive filaments to a liquid storage unit, wherein the fluid-permeable heater assembly extends across an opening in the housing of the liquid storage unit.

[0083] The step of filling the liquid storage unit with an aerosol-forming substrate can be performed before or after the step of fixing the heater assembly to the liquid storage unit.

[0084] The fixing step may include, for example, a step of heat-sealing, bonding, or welding the heater assembly to the liquid reservoir. The liquid reservoir may include a capillary material.

[0085] The features described with respect to one aspect may be equally applied to other aspects of the present invention. Specifically, the features described with respect to the first aspect may be equally applied to the second and third aspects.

[0086] As used herein, “electrical conductivity” means 1x10 -4 It means being formed from a material having a resistivity of Ωm or less. As used herein, “electrical insulation” means 1x10 4 It means being formed from a material having a resistivity of Ωm or greater. As used herein in relation to a heater assembly, "fluid permeability" means that a gaseous and possibly liquid aerosol-forming substrate can easily pass through the heater assembly.

[0087] Embodiments of the present invention will be further described for illustrative purposes only with reference to the accompanying drawings.

[0088] FIGS. 1a through 1d are schematic diagrams of an aerosol generating system comprising a cartridge according to an embodiment of the present invention. FIG. 1a is a schematic diagram of an aerosol generating device (10) and a separate cartridge (20) together forming an aerosol generating system. In this embodiment, the aerosol generating system is an electrically operated smoking system.

[0089] The cartridge (20) contains an aerosol-forming material and is configured to be received in a cavity (18) within 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 being inserted into the device, and the arrow (1) in FIG. 1a indicates the insertion direction of the cartridge.

[0090] 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), such as 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 FIG. 1 and a closed position as shown in FIG. 1d. As described below, the mouthpiece (12) is positioned in an open position to allow insertion and removal of a cartridge (20), and is placed in a closed position when the system needs to be used to generate an aerosol. The mouthpiece includes a plurality of air inlet (13) and outlet (15). When using, the user sucks or puffs on 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. The internal baffle (17) is provided to force air to flow through the cartridge and the mouthpiece (12).

[0091] 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 battery (14) and corresponding electrical contact on the cartridge (20).

[0092] FIG. 1b illustrates the system of FIG. 1a in which a cartridge is inserted into a cavity (18) and a cover (26) is removed. In this position, the electrical connection is seated on the electrical contact on the cartridge, as described below.

[0093] FIG. 1c illustrates the system of FIG. 1b in which the cover (26) is completely removed and the mouthpiece part (12) is moved to a closed position.

[0094] FIG. 1d illustrates 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 latch mechanism, as schematically illustrated in FIG. 2. FIG. 2 illustrates a main body (11) and a mouthpiece portion (12) connected by a hinged connecting part (21). The mouthpiece portion (12) includes a tooth portion (8) that extends inwardly. When the mouthpiece portion is in a closed position, the tooth portion (8) engages a latch (6) on the main body of the device. The latch (6) is deflected by a deflection spring (5) and engages with the tooth portion (8). A button (4) is fixed to the latch (6). The button (4) is pressed by a user against the action of the deflection spring (5) to separate the tooth portion (8) from the latch (6) and allow the mouthpiece portion to move to an open position. It will be obvious to those skilled in the art that other suitable mechanisms for holding the mouthpiece in a closed position, such as snap fits or magnetic closures, may also be used.

[0095] The mouthpiece portion (12) in the closed position holds a cartridge that makes electrical contact with the electrical connection portion (19), thereby ensuring 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 secures the surface of the cartridge and is pressed between the rigid mouthpiece housing element and the cartridge when the mouthpiece portion (12) is in the closed position. This ensures that a good electrical connection is maintained regardless of manufacturing tolerances.

[0096] Of course, alternatively or additionally, other mechanisms may be adopted to maintain a good electrical connection between the cartridge and the device. For example, the housing (24) of the cartridge (20) may have 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 threaded connection between the cartridge and the device may be used to ensure accurate rotational alignment and also to hold the cartridge within the cavity and ensure a good electrical connection. The threaded connection may extend only by less than half a rotation of the cartridge, or by several rotations. Alternatively or additionally, the electrical connection portion (19) may be deflected to contact a contact portion on the cartridge, as described later with reference to FIG. 8.

[0097] FIG. 3 is an exploded view of the cartridge (20). The cartridge (20) comprises a roughly circular cylindrical housing (24) having a size and shape selected to be accommodated within the cavity (18). The housing comprises a capillary material (22) immersed in a liquid aerosol-forming substrate. In this embodiment, the aerosol-forming substrate comprises 39% by weight glycerin, 39% by weight propylene glycol, 20% by weight water and flavoring agent, and 2% by weight nicotine. The capillary material is a material that actively transfers liquid from one end to the other and may be made from any suitable material. In this embodiment, the capillary material is formed of polyester.

[0098] The housing has an open end to which the heater assembly (30) is fixed. The heater assembly (30) comprises a substrate (34) having a hole (35) formed inside, a pair of electrical contacts (32) fixed to the substrate and separated from each other by a gap (33), and a plurality of electrically conductive heater filaments (36) connecting the hole and fixed to the electrical contacts on opposite sides of the hole (35).

[0099] The heater assembly (30) is covered by a removable cover (26). The cover comprises a liquid-impermeable plastic sheet that is bonded to the heater assembly with adhesive but can be easily peeled off. A tab is provided on the side of the cover so that the user can grasp the cover when peeling it off. Although the use of adhesive is described as a method of securing the impermeable plastic sheet to the heater assembly, it will be obvious to those skilled in the art that other methods similar to those 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.

[0100] FIG. 4 is an exploded view of an exemplary alternative cartridge. The cartridge of FIG. 4 has the same size and shape as the cartridge of FIG. 3 and has the same housing and heater assembly. However, the capillary material inside the cartridge of FIG. 4 is different from that of FIG. 3. Inside the cartridge of FIG. 4, there are two separate capillary materials (27, 28). A disc of the first capillary material (27) is provided to contact a heater element (36, 32) when in use. A larger body of the second capillary material (28) is provided on the side opposite the first capillary material (27) with respect to the heater assembly. Both the first capillary material and the second capillary material possess a liquid aerosol forming substrate. The first capillary material (27), which is in contact with the heater element, has a higher thermal decomposition temperature (at least 160°C, e.g., approximately 250°C) than the second capillary material (28). The first capillary material (27) effectively acts as a spacer separating the heater elements (36, 32) from the second capillary material (28) so that the second capillary material is not exposed to temperatures above its thermal decomposition temperature. A thermal gradient across the first capillary material causes the second capillary material to be exposed to temperatures below its thermal decomposition temperature. The second capillary material (28) may be selected to have superior wicking performance than the first capillary material (27), may hold more liquid per unit volume than the first capillary material, and may be less expensive than the first capillary material. In this embodiment, the first capillary material is a heat-resistant material such as fiberglass or a fiberglass-containing material, and the second capillary material is a polymer such as a suitable capillary material. An exemplary suitable capillary material includes the capillary material described herein, and in an alternative embodiment, may include high-density polyethylene (HDPE) or polyethylene terephthalate (PET).

[0101] FIG. 5a is a bottom perspective view of the cartridge of FIG. 3. From FIG. 5a, it can be seen that the heater assembly extends in a lateral plane and extends laterally out of the housing (24) to form a lip around the upper part of the housing (24). The exposed portion of the electrical contact portion (32) faces the insertion direction of the cartridge so that when the cartridge is fully inserted into the cavity (18), the exposed portion of the contact portion (32) contacts the electrical connection portion (19). A tab installed on the side of the cover (26) can be clearly seen so that the user can grasp the cover when peeling it off. FIG. 5a also illustrates a positioning portion (25) formed on the base of the cartridge to ensure the correct orientation of the cartridge within the cavity of the device. The positioning portion (25) is part of the injection-molded housing (24) and is configured to be received within a corresponding slot (not shown) within the base of the cavity (18). When the positioning part (25) is accommodated in a common slot, the contact part (32) is aligned with the connector (19).

[0102] FIG. 5b is a top perspective view of the cartridge of FIG. 3 with the cover removed. The heater filaments (36) are exposed through holes (35) in the substrate (34) so ​​that the evaporated aerosol-forming substrate can escape into the airflow by passing through the heater assembly.

[0103] The housing (24) is formed of a thermoplastic material such as polypropylene. In this embodiment, the heater assembly (30) is bonded to the housing (24) with adhesive. However, various methods of assembling and filling the cartridge are possible.

[0104] The cartridge housing may be formed by injection molding. The capillary material (22, 27, 28) may be formed by cutting a suitable length of the capillary material from a long rod of capillary fibers. The heater assembly may be assembled using the process described above with reference to FIGS. 11a, 11b, and 11c. In one embodiment, the cartridge is assembled by first inserting one or more capillary materials (22, 27, 28) into the housing (24). Then, a predetermined volume of a liquid aerosol-forming substrate is introduced into the housing (24) to immerse the capillary material. Then, the heater assembly (30) is pressed onto the open end of the housing and secured to the housing (24) by adhesive, welding, heat sealing, ultrasonic welding, or other methods obvious to those skilled in the art. The temperature of the housing is preferably maintained below 160°C during any sealing operation to prevent unnecessary volatilization of the aerosol-forming substrate. The capillary material may be cut to a length that extends from the open end of the housing (24) until it is compressed by the heater assembly. This facilitates the transport of the aerosol-forming material into the gap of the heater element in use.

[0105] In another embodiment, instead of sealing the heater assembly (30) after pressing it onto the housing (24), the heater assembly (30) may be joined to the housing (24) by first heating the open ends of the heater assembly and the housing and then pressing them together.

[0106] Additionally, it is possible to assemble the heater assembly (30) into the housing (24) before filling the housing with an aerosol-forming material and subsequently introducing the aerosol-forming material into the housing (24). In that case, the heater assembly may be secured to a cartridge using any of the methods described. Then, the heater assembly or the housing is punctured using a hollow needle and the aerosol-forming material is injected into the capillary material (22, 27, 28). Then, any opening formed by the hollow needle is sealed by heat sealing or using sealing tape.

[0107] FIG. 6 illustrates a first heater assembly (30) according to the present invention. The heater assembly comprises a mesh formed of 304L stainless steel, with a mesh size of approximately 400 Mesh US (approximately 400 filaments / inch). The diameter of the filaments is approximately 16 μm. The mesh is separated from one another by gaps (33) and connected to electrical contacts (32) formed of copper foil with a thickness of approximately 30 μm. The electrical contacts (32) are provided on a polyimide substrate (34) with a thickness of approximately 120 μm. The filaments forming the mesh define gaps between the filaments. In this embodiment, the width of the gaps is approximately 37 μm, but larger or smaller gaps may be used. By using a mesh of these approximate dimensions, a meniscus of the aerosol-forming substrate can be formed in the gaps, and the mesh of the heater assembly can attract the aerosol-forming substrate by capillary action. The open area of ​​the mesh, that is, the ratio of the area of ​​the gaps to the total area of ​​the mesh, is advantageously between 25 and 56%. The total resistance of the heater assembly is about 1 ohm. The mesh provides most of this resistance so that most of the heat is generated by the mesh. In this embodiment, the mesh has an electrical resistance more than 100 times greater than that of the electrical contacts (32).

[0108] The substrate (34) has electrical insulation properties and, in this embodiment, is formed from a polyimide sheet with a thickness of about 120 μm. The substrate is circular and has a diameter of 8 mm. The mesh is rectangular and has side lengths of 5 mm and 2 mm. These dimensions allow for the manufacture of a complete system having a size and shape similar to conventional cigarettes or cigars. Another example of dimensions known to be effective is a circular substrate with a diameter of 5 mm and a rectangular mesh of 1 mm x 4 mm.

[0109] FIG. 7 illustrates an exemplary alternative heater assembly according to the present invention. The heater assembly of FIG. 7 is identical to the heater assembly illustrated in FIG. 6, but the mesh (36) is replaced with an array of parallel electrically conductive filaments (37). The array of filaments (37) is formed of 304L stainless steel and has a diameter of about 16 μm. The substrate (34) and the copper contact portion (32) are as described above with respect to FIG. 6.

[0110] FIG. 8 illustrates another alternative heater assembly according to the present invention. The heater assembly of FIG. 8 is identical to the heater assembly illustrated in FIG. 7, but in the heater assembly of FIG. 8, filaments (37) are directly bonded to a substrate (34), and then contact portions (32) are bonded to the filaments. The contact portions (32) are separated from one another by an insulating gap (33) as described above and are formed from a copper foil with a thickness of about 30 μm. The same arrangement of substrate filaments and contact portions can be used in a mesh-type heater as illustrated in FIG. 6. Providing the contact portions as the outermost can be beneficial for providing reliable electrical contact with a power supply.

[0111] FIG. 9 illustrates an alternative heater assembly according to the present invention. The heater assembly of FIG. 9 comprises a plurality of heater filaments (38) formed integrally with electrical contacts (39). Both the filaments and the electrical contacts are formed from stainless steel foil etched to define the filaments (38). The contacts (39) are separated by a gap (33) except where they are joined by the filaments (38). The stainless steel foil is provided on a polyimide substrate (34). Additionally, the filaments (38) provide most of this resistance so that most of the heat is generated by the filaments. In this embodiment, the filaments (38) have an electrical resistance greater than 100 times that of the electrical contacts (39).

[0112] In the cartridge illustrated in FIGS. 3, 4, and 5, the contacts (32) and filaments (36, 38) are located between the substrate layer (34) and the housing (24). However, the heater assembly can be mounted in a different way in the cartridge housing so that the polyimide substrate is immediately adjacent to the housing (24). FIG. 10 illustrates this type of configuration. FIG. 10 illustrates a heater assembly comprising a stainless steel mesh (56) fixed to copper foil contacts (52). The copper contacts (52) are fixed to the polyimide substrate (54). A hole (55) is formed in the polyimide substrate (54). The polyimide substrate is welded to the housing (24) of the cartridge. A capillary material (22) immersed in an aerosol-forming substrate fills the housing and extends through the hole to contact the mesh (55). The cartridge is depicted as being housed within the main body (11) of the device and maintained between the electrical connection part (59) and the mouthpiece part (12). In this embodiment, the connector (59) is configured to penetrate the polyimide substrate (54) as illustrated so that the electrical connection part (59) is electrically connected to the contact part (52). The electrical connection part is manufactured to have a sharp end and comes into contact with the heater assembly by means of a spring (57). The polyimide substrate may be pre-scored to ensure good electrical contact, or may even have a hole so that it is not necessary to penetrate the substrate. The spring (57) also ensures that good electrical contact is maintained between the contact part (52) and the connector (59) regardless of the system's orientation with respect to gravity.

[0113] One means for ensuring the correct orientation of the cartridge (20) within the cavity (18) of the device has been described with reference to FIGS. 5a and 5b. The positioning portion (25) may be formed as part of the molded cartridge housing (24) to ensure the correct orientation. However, it will be apparent that other methods of ensuring the correct orientation of the cartridge are possible. Specifically, if the housing is injection molded, the shape of the cartridge is almost not limited. Once the desired internal volume of the cartridge has been selected, the shape of the cartridge can be adjusted to fit any cavity. FIG. 11a is a base drawing of one possible cartridge housing (70) that allows the cartridge to be oriented in two possible orientations. The cartridge housing (70) includes two symmetrically arranged grooves (72). The grooves may extend partially or completely to the sides of the housing (70). Corresponding ribs (not shown) may be formed on the walls of the cavity of the device so that the cartridge can be accommodated in the cavity in only two possible orientations. In the embodiment of FIG. 11a, the cavity may have only one rib so that one of the grooves (72) is not filled by a rib and can be used as an airflow channel within the device. Of course, it is also possible to provide only a single groove in the housing to restrict the cartridge to a single orientation within the cavity. This is illustrated in FIG. 11b, which shows a cartridge housing (74) having a single groove (76).

[0114] The aforementioned embodiments have a cartridge having a housing with a substantially circular cross-section, but a cartridge housing of other shapes, such as a rectangular cross-section or a triangular cross-section, may also be formed. Such housing shapes ensure a desired orientation within a cavity of the corresponding shape, thereby ensuring an electrical connection between the device and the cartridge.

[0115] The capillary material (22) is advantageously oriented within the housing (24) to deliver liquid to the heater assembly (30). When a cartridge is assembled, the heater filaments (36, 37, 38) may come into contact with the capillary material (22), so that the aerosol-forming substrate can be delivered directly to the mesh heater. FIG. 12a is a detailed view of the filaments (36) of the heater assembly showing the meniscus (40) of the liquid aerosol-forming substrate between the heater filaments (36). It can be seen that most of the heat generated by the heater assembly is delivered directly to the aerosol-forming substrate by the aerosol-forming substrate coming into contact with most of the surface of each filament. In contrast, in a conventional wick and coil heater assembly, only a small portion of the heater wire comes into contact with the aerosol-forming substrate. FIG. 12b is a detailed view similar to FIG. 12a illustrating an example of a capillary material (27) extending into the gaps between filaments (36). The capillary material (27) is the first capillary material illustrated in FIG. 4. It can be seen that by providing a capillary material comprising threads of fibers extending into the gaps between filaments (36), it is possible to ensure the transfer of liquid to the filaments.

[0116] When in use, the heater assembly operates by resistive heating. Current flows through the filaments (36, 37, 38) and, under the control of the control electronic device (16), heats the filaments within a desired temperature range. The mesh or array of filaments has a significantly greater electrical resistance than the electrical contacts (32) and electrical connections (19), so that the high temperature is confined to the filaments. The system may be configured to generate heat by supplying current to the heater assembly in response to a user puff, or it may be configured to generate heat continuously while the device is in the “on” state. Different materials for the filaments may be suitable for different systems. For example, in a continuous heating system, graphite filaments are suitable because they have relatively low resistivity and are compatible with low-current heating. In a puff-start system where heat is generated in short bursts using high-current pulses, stainless steel filaments with a large specific heat capacity may be more suitable.

[0117] In the puff activation system, the device may include a puff sensor configured to detect when the user inhales air through the mouthpiece. The puff sensor (not shown) is connected to a control electronic device (16), and the control electronic device (16) is configured to supply current to the heater assembly (30) only when it is determined that the user is puffing the device. Any suitable airflow sensor, such as a microphone, may be used as the puff sensor.

[0118] In a possible embodiment, a change in the temperature of the heater element may be detected using one or more of the filaments (36, 38) or a change in the overall resistance of the heater element. This can be used to regulate the power supplied to the heater element to ensure that the heater element is maintained within a desired temperature range. Additionally, a sudden change in temperature may be used as a means to detect a change in the airflow passing through the heater element caused by a user puff to the system. One or more of the filaments may be dedicated temperature sensors and may be formed from a material having a suitable temperature coefficient of resistance for them, such as an iron-aluminum alloy, Ni-Cr, platinum, tungsten, or alloy wire.

[0119] The airflow through the mouthpiece section when the system is in use is illustrated in FIG. 1d. The mouthpiece section includes internal baffles (17) which are integrally molded with the outer walls of the mouthpiece section and ensure that when air is drawn from the inlet section (13) to the outlet section (15), the air flows over the heater assembly (30) on the cartridge where the aerosol-forming material is evaporating. As the air passes through the heater assembly, the evaporated material is entrained by the airflow and cooled to form an aerosol before exiting the outlet section (15). Accordingly, in use, the aerosol-forming material passes through the heater assembly by passing through the gaps between the filaments (36, 37, 38) as the aerosol-forming material evaporates.

[0120] The possibilities for the material and manufacture of the heater assembly may vary. FIG. 13a is a schematic diagram of a first method for manufacturing a heater assembly. A roll of polyimide film (80) has an array of holes (82). The holes (82) may be formed by stamping. Bands of copper foil (84) are plated onto the polyimide film (80) between the holes. Then, ribbons of stainless steel mesh (86) are clad onto the polyimide film (80) over the holes (82) and on top of the copper foil (84) in a direction perpendicular to the bands of copper foil. Then, individual heater assemblies (30) are cut or stamped around each hole (82). Each heater assembly (30) includes a portion of copper foil on the opposite sides of the holes forming electrical contacts, and a strip of stainless steel mesh connects the holes from one portion of copper to another as shown in FIG. 6.

[0121] FIG. 13b illustrates another possible manufacturing process. In the process of FIG. 13b, a polyimide film (80) of the type used in the process of FIG. 13a is clad with a stainless steel foil (90). An array of holes (82) is formed in the polyimide film (80), but these holes are covered by the stainless steel foil (90). Then, the stainless steel foil (90) is etched to define filaments (38) connecting the holes (82) and individual contacts on opposite sides of the holes. Then, individual heater assemblies (92) are cut or stamped around each hole (82). This provides a heater assembly of the type illustrated in FIG. 9.

[0122] FIG. 13c illustrates another alternative process. In the process of FIG. 13c, a graphite-based fabric (100) is first prepared. The graphite-based fabric (100) comprises bands of electrically resistive fibers suitable for use as heater filaments, and adjacent bands of relatively non-conductive fibers. These bands of fibers are woven together with bands of relatively electrically conductive fibers extending perpendicularly to the resistive non-conductive fibers. Then, this fabric (100) is bonded to a layer of polyimide film (80) of the type described with reference to FIG. 13a and FIG. 13b having an array of holes (82). Then, individual heater assemblies (102) can be cut or stamped around each hole. Each heater assembly (102) comprises a portion of a band of conductive fibers on opposite sides of the hole, and a band of electrically resistive fibers connecting the hole.

[0123] The cartridge design illustrated in FIGS. 5a and 5b has several advantages. However, alternative cartridge designs using the same type of heater assembly are also possible. FIG. 14 illustrates an alternative cartridge design suitable for different patterns of airflow through the system. In the embodiment illustrated in FIG. 14, the cartridge (108) is configured to be inserted into the device in the direction indicated by the arrow (110). The cartridge (108) includes a housing (112) that is open on one side and has a semi-cylindrical shape. A heater assembly (114) is provided across the open side and is bonded or welded to the housing (112). The heater assembly (114) includes an electrically insulating substrate (116), such as polyimide, with holes formed therein. A heater element comprising a stainless steel mesh (118) and a pair of contact strips (120) is bonded to the electrically insulating substrate (116) and connects the holes. The contact strips (120) are bent around the housing (112) to form contact pads on the curved surface of the housing. The electrical contact pads are configured to contact corresponding contact parts (not shown) of an aerosol generating device. The housing (112) is filled with a capillary material (not shown in FIG. 14) immersed in an aerosol forming substrate, as described above with respect to the embodiments illustrated in FIG. 1a through 1d.

[0124] The cartridge illustrated in FIG. 14 is configured for an airflow passing through the heater assembly (114) in the opposite direction of the arrow (110). Air is drawn into the system through an air inlet provided in the main body of the device and passes through the heater assembly (114) into the mouthpiece of the device (or cartridge) and into the user's mouth. The air drawn into the system may be directed in a direction parallel to the mesh (118), for example, by the appropriate arrangement of the air inlets.

[0125] Alternative embodiments of the cartridge (108) are illustrated in FIGS. 15a and FIGS. 15b. FIGS. 15a further includes spaced-apart contact strips (120) extending along the length of a surface having a mesh (118). FIGS. 15b further includes contact portions (120) that are approximately L-shaped. The cartridge design illustrated in both FIGS. 15a and FIGS. 15b may be used to provide a larger contact area to further ensure easy contact with the contact portions (19) when necessary. The strips (120) as illustrated in FIGS. 15a may also be configured to slide into a contact portion (19) configured with a rail configuration (not shown) to accommodate the strips (120) for positioning the cartridge further. This rail configuration can advantageously provide periodic cleaning of the contact portions (19) because the insertion and removal of the cartridge based on friction of the contact portion sliding inside and outside the rails has a cleaning effect.

[0126] FIG. 16 illustrates another embodiment of an aerosol generating system comprising a fluid-permeable electric heater assembly. FIG. 16 illustrates a system in which a heater assembly (30) is provided at the end of a cartridge (20) opposite the mouthpiece portion (12). Airflow enters the air inlet (1601) and passes through the assembly via the air outlet (1603) along the flow path (1605). The electric contacts may be placed at any convenient location. This configuration is advantageous because it allows for shorter electrical connections within the system.

[0127] Other cartridge designs comprising the heater assembly according to the present invention may now be devised by those skilled in the art. For example, the cartridge may include a mouthpiece, may include more than one heater assembly, and may have any desired shape. Additionally, the heater assembly according to the present invention may be used in systems of a different type than those already described, for example, humidifiers, air purifiers, and other aerosol generating systems.

[0128] 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.

[0129] FIG. 17 illustrates a cross-section of a cartridge system in which a flow path includes airflow through a cartridge. A fluid-permeable heater, for example, a mesh heater (30), includes electrically conductive heater filaments (36) connecting the aperture of a housing (400). A sealing layer (48), for example, a polymer layer, is provided between the upper rim of the housing (400) and the heater (30) to seal the upper part of the housing (400). Additionally, a sealing disc (47), for example, a polymer disc, is provided on the upper side of the heater (30). By the sealing disc (47), the airflow through the heater can be controlled, and in particular, airflow constraints can be provided. Additionally, the sealing disc may be placed on the lower side of the heater (30).

[0130] The cartridge housing (400) contains a liquid-containing capillary material, such as a high-retention material or high-separation material (HRM) (41), which functions as a liquid reservoir and directs the liquid toward the heater (30) to evaporate from the heater. Another capillary material, such as a capillary disc (44), for example, a fiber disc, is placed between the HRM (41) and the heater (30). The material of the capillary disc (44) may have better heat resistance than the HRM (41) because it is closer to the heater (30). The capillary disc is kept wet with the aerosol-forming liquid of the HRM to ensure that the liquid evaporates when the heater is activated.

[0131] The housing (400) is provided with an air-permeable bottom section (45). The air-permeable bottom section is provided with an airflow inlet (450). The airflow inlet (450) allows air to flow into the housing in only one direction through the bottom section (45). No air or liquid can leave the housing through the air-permeable bottom section (45). The air-permeable bottom section (45) may include, for example, a semipermeable membrane as the airflow inlet (450) and may be a bottom cover including one or more one-way valves as described below.

[0132] When low pressure is dominant on the side of the heater, as is the case during puffing, air can flow into the cartridge through the airflow inlet (450). The airflow (200) flows through the HRM (41) and the heater (30). Subsequently, the aerosol-containing airflow (200) flows to the downstream end of the aerosol generator in a channel preferably positioned at the center of the mouthpiece.

[0133] The side walls of the housing (400) may also have lateral air-permeable portions (46) for providing lateral airflow within the housing. The lateral air-permeable portions (46) may be designed as an airflow inlet (450) of the lowest air-permeable portion (45).

[0134] In FIG. 18, the structure and function of the cartridge system are basically the same as those shown in FIG. 10. However, the HRM (41) is provided with a central opening (412). Air entering the airflow inlet (450) at the bottom of the housing (45) passes through the central opening (412). The airflow passes along the side of the HRM in the cartridge. By providing an optional lateral air-permeable portion (46) on the side wall of the housing (400), lateral airflow can be provided through the HRM (41).

[0135] FIG. 19 shows an exploded view of a cartridge system similar to FIG. 11. A ring-shaped tubular HRM (41) is provided in a housing (400). The lower part (45) of the housing is a disc containing a one-way valve (49) positioned at the center of the disc and aligned with the central opening (412) of the HRM (41). This one-way valve may be, for example, a commercially available valve, such as one used in medical devices or baby bottles.

[0136] FIG. 20 is a cross-sectional view of another embodiment of the cartridge system. The same reference numerals are used for the same or similar elements. In this embodiment, the housing (400) is filled with an aerosol-forming liquid (411). The housing may be made of metal, plastic material, e.g., polymer material, or glass. The valve (49) may be formed directly into the bottom portion (45) of the housing. The bottom portion (45) may also have a cavity for a hermetic assembly with the valve. Preferably, because the valve is made of a flexible material, a rigid assembly with the bottom portion material can be achieved.

[0137] In the cartridge system described above with respect to FIGS. 17 to 20, the cartridge housing (400) may also be a separate cartridge container in addition to the cartridge housing described in FIG. 1, for example. In particular, the liquid (411) containing cartridge is a pre-manufactured product that can be inserted into a cartridge housing provided in an aerosol generating system to accommodate a pre-manufactured cartridge. Explanation of the symbols

[0138] 1,110: Arrow 4: Button 5: Bias spring 6: Latch 8: Tooth shape 10: Aerosol generator 11: Main body 12: Mouthpiece 13: Air inlet 15: Outflow section 14: Battery 16: Electronic devices 17: Internal baffle 18: Joint 19: Electrical connection part 20: Cartridge 21: Connection 22, 27, 28: Capillary substances 24,70,74,112,400: Housing 25: Position setting section 26: Cover 30: Heater assembly, mesh heater 32,36: Heater element 32: Electrical contact part 33: Gap 34,116: Entry 35,82: hole 36: Filament, Mesh 36,37,38: Filament 39: Contact part 40: Meniscus 41: HRM 44,47: Disk 45: Lowest 46: Air permeable part 48: Sealing layer 49: Valve 52: Contact part 56,86: Steel Mesh 54: Polyimide substrate 55: Hole, Mesh 57: Spring 59: Connection part, connector 72,76: Home 80: Film 84,90: Foil 92,102,114: Assembly 100: Fabric 108: Cartridge 118: Steel Mesh 120: Strip 200: Airflow 411: Liquid 412: Opening 450: Inlet 1601: Air inlet 1603: Air outlet 1605: Flow path

Claims

Claim 1 A cartridge for use in an electrically operated aerosol generating system, wherein the cartridge comprises: a liquid reservoir comprising a housing having a liquid aerosol forming material, wherein the housing has an opening; and a fluid permeable heater assembly comprising a plurality of electrically conductive filaments, wherein the fluid permeable heater assembly is fixed to the housing and extends across the opening of the housing. Claim 2 In claim 1, the area of ​​the electrically conductive filaments is 25 mm 2 Lee Ha-in, cartridge. Claim 3 In claim 1 or 2, the fluid-permeable heater assembly is a substantially flat cartridge. Claim 4 A cartridge comprising a mouthpiece portion further comprising, in paragraph 1 or 2. Claim 5 A cartridge according to claim 1 or 2, wherein the housing of the liquid storage portion contains a capillary material configured to deliver a liquid aerosol forming substrate to the heater assembly. Claim 6 In paragraph 5, the capillary material extends into the gaps between the electrically conductive filaments, forming a cartridge. Claim 7 A cartridge according to claim 5, wherein the capillary material comprises a first capillary material and a second capillary material, the first capillary material is in contact with the heater assembly, the second capillary material is in contact with the first capillary material and is spaced apart from the heater assembly by the first capillary material, and the first capillary material has a higher pyrolysis temperature than the second capillary material. Claim 8 In claim 7, the second capillary material is a cartridge holding 20 to 160 mg of liquid. Claim 9 A cartridge according to claim 8, wherein the thermal decomposition temperature of the first capillary material is at least 160°C. Claim 10 In claim 1 or 2, the heater assembly comprises a cartridge comprising an electrically insulating substrate upon which the filaments are supported. Claim 11 In claim 10, the cartridge, wherein the filaments extend across an aperture formed within the electrically insulating substrate. Claim 12 A cartridge according to claim 1 or 2, wherein the heater assembly comprises at least one filament made of a first material and at least one filament made of a second material different from the first material. Claim 13 A cartridge according to claim 1 or 2, wherein the heater assembly comprises an electrically conductive contact portion in contact with a plurality of filaments. Claim 14 In paragraph 13, the electrically conductive contact portion is a cartridge integrated with a plurality of filaments. Claim 15 In paragraph 13, the heater assembly extends in a lateral plane, and the electrically conductive contact extends laterally out of the housing of the liquid storage part, a cartridge. Claim 16 A cartridge according to claim 1 or 2, wherein the liquid reservoir is located on a first side of the electrically conductive filaments so that the airflow passing through the electrically conductive filaments entrains the evaporated liquid aerosol-forming substrate, and during use, an airflow channel is located on the opposite side of the electrically conductive filaments to the liquid reservoir. Claim 17 A cartridge according to claim 1 or 2, wherein the housing comprises a cap and a tank, the cap closes the tank, and the cap is in close contact with the heater assembly. Claim 18 An aerosol generating system comprising a cartridge and a main unit according to claim 1 or 2, wherein the cartridge is removablely coupled to the main unit, and the main unit comprises a power supply unit. Claim 19 An aerosol generating system according to claim 18, further comprising an electric circuit connected to the heater assembly and an electric power source, wherein 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 from the electric power source to the heater assembly depending on the electrical resistance of the heater assembly or one or more filaments. Claim 20 In paragraph 18, the above system is an aerosol generating system that is an electrically operated smoking system. Claim 21 A method for manufacturing a cartridge for use in an electric aerosol generating system, comprising: providing a liquid storage unit comprising a housing having an opening; filling the liquid storage unit with a liquid aerosol forming substrate; and fixing a fluid permeable heater assembly comprising a plurality of electrically conductive filaments to the liquid storage unit, wherein the fluid permeable heater assembly extends across the opening of the housing of the liquid storage unit. Claim 22 delete Claim 23 delete Claim 24 delete Claim 25 delete Claim 26 delete Claim 27 delete

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