Cartridge for an aerosol generating system

Abstract

To provide a cartridge for use in an aerosol generation system.SOLUTION: The cartridge includes a liquid storage portion including a housing (24) for holding a liquid aerosol forming base substance, the liquid storage portion including at least two portions in fluid communication with each other. A first portion (32) of the liquid storage portion includes a heater assembly (46), a first capillary material (36) provided in contact with the heater assembly, and a second capillary material (38) in contact with the first capillary material and spaced from the heater assembly by the first capillary material. A second portion (34) of the liquid storage portion includes a container (e.g., a tank) for holding the liquid aerosol forming base substance and supplies a liquid to the second capillary material.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to aerosol generating systems. In particular, the present invention relates to handheld aerosol generating systems, such as electrically operated smoking systems. Aspects of the present invention relate to cartridges for aerosol generating systems, in particular electrically operated smoking systems. [Background technology]

[0002] One type of aerosol generating system is an electrically operated smoking system. Handheld electrically operated smoking systems are well known, with a device portion including a battery and control electronics, a cartridge portion including a supply of aerosol-forming substrate, and an electrically operated vaporizer. A cartridge with both a supply of aerosol-forming substrate and a vaporizer is sometimes called a "cartomizer". The vaporizer generally includes a heater wire coil wound around an elongated wick immersed in a liquid aerosol-forming substrate. A capillary material immersed in the aerosol-forming substrate supplies liquid to the wick. The cartridge portion generally includes not only a supply of aerosol-forming substrate and an electrically operated vaporizer, but also a mouthpiece through which the user draws the aerosol into the mouth during use by sucking.

[0003] In some types of electrically operated aerosol generating devices, a reservoir of aerosol-forming liquid is provided in a tank. When used in an aerosol generating system, the liquid is transported by capillary action from the tank to the wick of the coiled-wick heater assembly where the liquid is vaporized. When a user draws on the mouthpiece, air flows through the heater assembly and the generated aerosol is inhaled by the user.

[0004] A problem with such tank devices is that if the device is held at an angle where the liquid aerosol-generating substrate in the tank does not contact the capillary system, the system will stop generating aerosol. Moreover, these systems can be prone to leaking, for example, if liquid from the tank floods the core or leaks through the airflow paths.

[0005] In other systems, the liquid reservoir of the cartridge is filled with a capillary medium. The liquid aerosol-generating substrate is held within the capillary material and delivered to the wick. In such systems, the problems of the holding angle and risk of leakage mentioned above may be reduced. However, some residual liquid remains within the capillary material after use, resulting in waste. Furthermore, puff delivery in such systems may be inconsistent due to reduced saturation of the capillary medium during use, which does not allow for a consistent high quality smoking experience.

[0006] It would be desirable to have a cartridge that avoids one or more of the above-mentioned or other disadvantages, for example, that avoids waste of aerosol-generating substrate liquid, while preferably maintaining or improving the aerosol generation performance of the aerosol generating system in which the cartridge is used. Summary of the Invention

[0007] According to a first aspect of the present invention, there is provided a cartridge for use in an aerosol generating system, e.g. an electrically operated aerosol generating system, comprising a liquid storage portion for holding a liquid aerosol-forming substrate. The liquid storage portion comprises at least two portions in fluid communication with each other. The first portion of the liquid storage portion comprises a heater assembly, a first capillary material provided in contact with the heater assembly, and a second capillary material in contact with the first capillary material and spaced from the heater assembly by the first capillary material. The second portion of the liquid storage portion preferably comprises a container for holding the aerosol-forming substrate in liquid form and is arranged to supply liquid to the second capillary material. The second portion of the liquid storage portion may be substantially empty and may comprise a tank suitable for holding the aerosol-forming substrate in liquid form.

[0008] The capillary material is preferably designed to have the capacity to hold a sufficient liquid substrate for several puffs. The capillary material is located in contact with the heater so that the heater is provided with sufficient aerosol-generating liquid independently of the retention angle of the aerosol-generating liquid. The remaining internal volume of the liquid storage portion does not contain capillary material and represents an empty tank for storing aerosol-generating liquid. Under normal handling conditions, the aerosol-generating medium, particularly the aerosol-generating smoking device, is moved between puffs and the capillary material regularly comes into contact with and reabsorbs new aerosol-generating liquid.

[0009] Because a smaller amount of capillary material is used, the amount of residual liquid remaining in the capillary material after use of the cartridge is less than that of conventional cartridges in which the entire liquid reservoir is filled with capillary material. Moreover, performance tests have shown that the TPM (total particulate matter) yield of an aerosol-generating smoking device equipped with the cartridge of the present invention is in many instances at least comparable to the performance of aerosol-generating smoking devices equipped with currently available cartridges.

[0010] The liquid capacity of the capillary material is preferably such that it can hold enough liquid for 30-40 or more puffs. A 3 second puff can contain about 1 mg to 4 mg of liquid, for example 3 mg to 4 mg of liquid. The capacity of the capillary material is preferably between about 30 mg to about 160 mg, preferably 90 mg to about 160 mg or more, or more preferably 100 mg to 150 mg, for example 130 mg. If there are two layers of capillary material, the capacity of the first and second layers is such that about 10-20 weight percent of the liquid volume is in the first layer. For example, if the capacity of the capillary material is for 30 puffs, the capacity of the first layer can be for about 5 puffs and the capacity of the second layer can be for about 25 puffs.

[0011] Without being bound by any particular theory, it is believed that a capillary material with a capacity for several puffs (e.g., 30 or more puffs) reduces the risk of leakage from the device. It is believed that if the capillary material is too small, upon smoking, the liquid may be drawn directly through the capillary material and heater without being vaporized from the reservoir, leading to leakage. Also, a capacity of 90 mg or more allows multiple puffs to be removed from the device even when the liquid in the reservoir is not in direct contact with the capillary material.

[0012] The heater assembly may be substantially planar and may include a conductive filament, eliminating the need for any winding of heater wire around a capillary wick.

[0013] The conductive filaments may lie in a single plane, which allows for easier handling during manufacturing and provides a robust construction.

[0014] The conductive filaments may define gaps between the filaments, the gaps may have a width between 10 μm and 100 μm. The filaments may induce capillary action within the gaps such that a liquid to be vaporized in use is drawn into the gaps, increasing the contact area between the heater assembly and the liquid.

[0015] The conductive filaments may form a mesh with a size of 160-600 mesh US (±10%) (i.e. 160-600 filaments per inch (±10%)). The gap width is preferably 75 μm-25 μm. The open area fraction of the mesh, which is the ratio of the gap area to the total area of ​​the mesh, is preferably 25-56%. The mesh may be formed using different types of weaves or lattice structures. Alternatively, the conductive filaments consist of a series of filaments aligned parallel to one another.

[0016] The conductive filaments may have a diameter of 10 μm to 100 μm, preferably 8 μm to 50 μm, and more preferably 8 μm to 39 μm. The filaments may have a round or flat cross-section. The heater filaments may be formed by etching a sheet material (such as a foil). This may be particularly advantageous when the heater assembly comprises a series of parallel filaments. Where the heater assembly comprises a mesh or woven fabric of filaments, the filaments may be formed individually and woven together.

[0017] As described in relation to the first embodiment, the heater assembly may include at least one filament made from a first material and at least one filament made from a second material different from the first material.

[0018] The heater assembly may comprise an electrically insulating substrate on which a filament is supported, the filament extending across an opening formed in the substrate. The electrically insulating substrate may comprise any suitable material, but is preferably a material that can withstand high temperatures (greater than 300 degrees Celsius) and rapid temperature changes. One example of a suitable material is a polyimide film such as Kapton®.

[0019] The heater assembly may include conductive contacts in contact with the plurality of filaments. The conductive contacts may be provided between a housing of the liquid storage portion and an electrically insulated substrate. The conductive contacts may be provided between the filaments and the electrically insulated substrate. An opening may be formed in the insulating layer, and the cartridge may include two conductive contacts located on opposite sides of the opening.

[0020] The capillary material is preferably a material that actively transports liquid from one end of the material to the other, and is advantageously oriented within the housing to transport the liquid to the heater assembly.

[0021] The second capillary material may have a fibrous structure, where the fibers are generally oriented in the direction of travel through the liquid to the heater. The first capillary material may have less oriented fibers. For example, the first capillary material may have a felt structure.

[0022] The capillary material may have a fibrous or spongy structure. The capillary material preferably comprises a bundle of capillaries. For example, the capillary material may comprise a number of fibers or threads, or other fine tubes. The fibers or threads may be generally aligned to transport the liquid to the heater. Alternatively, the capillary material may comprise a spongy or foam-like material. The structure of the capillary material forms a number of small holes or tubes through which the liquid can travel by capillary action. The capillary material may comprise any suitable material or combination of materials. Examples of suitable materials include spongy or foam materials, ceramic or graphite-based materials in the form of fibers or sintered powders, foamed metal or plastic materials, fibrous materials made of spun or extruded fibers (such as cellulose acetate, polyester, or bonded polyolefin, polyethylene, terylene or polypropylene fibers, nylon fibers or ceramics). The capillary material may have any suitable capillary and porosity to be used with different liquid physical properties. A liquid has physical properties, including but not limited to viscosity, surface tension, density, thermal conductivity, boiling point and vapor pressure, that enable it to move through a capillary device by capillary action.

[0023] The capillary material may be in contact with a heater, e.g., a conductive filament. The capillary material may extend into the gap between the filaments. The heater assembly may draw the liquid aerosol-forming substrate into the gap by capillary action. The capillary material may be in contact with the conductive filament over substantially the entire length of the opening.

[0024] The housing may include two or more different capillary materials, where a first capillary material in contact with the heater element has a higher pyrolysis temperature and a second capillary material in contact with the first capillary material but not the heater element has a lower pyrolysis 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 pyrolysis temperature. As used herein, "pyrolysis temperature" means the temperature at which a material begins to decompose and lose mass by generating gaseous by-products. The second capillary material may advantageously occupy a larger volume than the first capillary material, but may also hold more aerosol-forming substrate than the first capillary material. The second capillary material may have better wick performance than the first capillary material. The second capillary material may be less expensive than the first capillary material. The second capillary material may be polypropylene.

[0025] The first capillary material may be selected from the group of Kevlar felt, ceramic paper, ceramic felt, carbon felt, cellulose acetate, hemp felt, PET / PBT sheet, cotton pad, porous ceramic disc or porous metal disc.

[0026] Preferred materials include Kevlar felt, ceramic paper, ceramic felt, a porous ceramic disc or a porous metal disc. The first capillary material may comprise fiberglass paper or felt. Preferably, the first capillary material is substantially free of organics.

[0027] The porosity of the first capillary material is preferably smaller than that of the second capillary material. The pore size of the first capillary material is preferably smaller than that of the second capillary material. The pore size may be measured, for example, as an average pore size for a region of the capillary material. In this way, it is found that the aerosol-generating substrate is transferred to the heater more efficiently. In a broad aspect of the invention, a cartridge is provided that includes a heater and a capillary material in contact with the heater for delivering the aerosol-generating substrate to the heater, where the porosity or pore size of the region of the capillary material adjacent to the heater is smaller than the porosity or pore size of the region of the capillary material remote from the heater. Thus, a single material, for example, with a pore size gradient in one or more dimensions thereof, may be used.

[0028] The first capillary material may have a fiber / pore size of 0.1-50 μm, preferably 0.5-10 μm, and most preferably about 4 μm. The first capillary material has a density of less than 2 g / ml, preferably about 0.5 g / ml.

[0029] The second capillary material may be a so-called high retention material (HRM) selected from the group of polypropylene (PP), polyethylene (PE), polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), rolled nonwoven materials or rolled felt. The second capillary material preferably comprises a polymeric material. The material may, for example, comprise a coating to reduce hydrophobicity.

[0030] The second capillary material may have a fiber / pore size of 1-100 μm, preferably 15-40 μm, and most preferably about 25 μm. The second capillary material has a density of less than 1 g / ml, preferably 0.1-0.3 g / ml.

[0031] The first capillary material may separate the heater assembly from the second capillary material by a distance of at least 0.8 mm (at least 1.5 mm), but preferably between 0.8 mm and 2 mm to provide a sufficient temperature drop across the first capillary material.

[0032] The first and second capillary materials may be made of the same material and may be distinguished from one another only in that they exhibit different porosities or different capillary actions, for example, the first capillary material may be compressed such that its pore size or porosity is reduced and its capillary action is increased as compared to the second capillary material which may be used uncompressed or at least to a lesser extent compressed.

[0033] In one preferred embodiment, the first and second materials are manufactured from a single continuous piece of the same base material, and more preferably, the material is processed such that a gradient of pore size or porosity is oriented in a direction towards the heater element or opening, such that the pore size or porosity decreases, e.g., continuously decreases, within the capillary material towards the heater element.

[0034] At least the first capillary material is preferably compressed after insertion into the first part of the liquid storage housing so that its effective pore size or porosity is reduced. For example, the single continuous element may have the shape of a truncated cone, where the diameter of the circular base of the truncated cone is larger than the inner diameter of the cylindrical housing of the liquid storage, while the diameter of the truncated tip of the cone substantially corresponds to the inner diameter of the cylindrical housing of the liquid storage. After insertion, the capillary material at the base of the capillary material cone is more compressed than in the region of the truncated tip. The more compressed material represents the first capillary material, and the less compressed material represents the second capillary material. A person skilled in the art will easily understand that the resulting compression gradient depends on the relative shapes selected for the capillary element and the liquid storage housing.

[0035] In a particularly preferred embodiment, the capillary element has a regular cylindrical shape with a circular cross section and a predetermined diameter. The interior surface of the housing includes a tapered portion at the open end such that the capillary material is compressed by the tapered portion after inserting the capillary material into the housing. The interior surface of the housing preferably has a conical shape such that the inner diameter increases continuously from the open end to the closed end of the cartridge.

[0036] The first capillary material and the second capillary material may comprise different regions of the same capillary material element. When entrained within the housing, compression of the capillary material may be performed such that the pore size or porosity of the capillary material decreases or decreases continuously toward the heater assembly.

[0037] In a further embodiment, the first and second capillary materials are also formed from a single continuous piece of the same material. The capillary material may be a rectangular web of capillary material with a thickness of less than 50% of the inner diameter of the cylindrical housing of the cartridge, but preferably about 25% of the inner diameter of the cylindrical housing of the cartridge. The width of the web of capillary material corresponds to the peripheral circumference of the housing. The web of capillary material may have any length desired, but is preferably about half the length of the housing of the cartridge. The web of capillary material is rolled to form a cylindrical shape. By rolling, the central portion of the web is compressed to a greater degree than the outer portions of the web, such that a pore size or porosity gradient is obtained in the radial direction of the rolled web of capillary material. An air channel is formed in the center of the rolled capillary material. A tubular fluid-permeable heater element is provided in the air channel, such that the heater is in direct contact with the inner surface of the rolled capillary material. When the capillary material is rolled, the portions of the material closer to the central axis of the cylinder are compressed more than the material in the portions located radially outward of the capillary material. Thus, a pore size gradient is again obtained, but now the pore size of the capillary material decreases continuously within the capillary material in the direction of the heater element. The capillary material is in fluid communication with a liquid reservoir, where the liquid reservoir is provided within a portion of the housing not occupied by the capillary material. A partition is provided within the housing so that the liquid substrate is not in direct communication with the air flow channel.

[0038] The web of capillary material may also comprise multiple layers of capillary material so that the liquid retention properties of the capillary material can be designed in any manner desired that is most appropriate for a given aerosol generation system.

[0039] In certain preferred embodiments, the heater element is co-wound with the capillary material such that a single manufacturing step results in a unitary capillary material containing the radial gradient and heating element.

[0040] The liquid storage portion can be located on a first side of the conductive filament and the airflow channel can be located in the liquid storage portion from an opposite side of the conductive filament such that the airflow passing through the conductive filament is mixed into the vaporized liquid aerosol-forming substrate.

[0041] The aerosol generating system preferably includes a housing. The housing is preferably elongated. The housing may include any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics or composites containing one or more of these materials, or thermoplastics suitable for food or pharmaceutical applications, such as, for example, polypropylene, polyetheretherketone (PEEK) and polyethylene. The material is preferably lightweight and not brittle. The material may include PET, PBT or PPS.

[0042] The aerosol generating system is preferably portable. The aerosol generating system may have a size comparable to a conventional cigar or cigarette. The overall length of the smoking system may be from about 30 mm to about 150 mm. The outer diameter of the smoking system may be from about 5 mm to about 30 mm.

[0043] An aerosol-forming substrate is a substrate capable of releasing a volatile compound capable of forming an aerosol. The volatile compound can be released by heating the aerosol-forming substrate.

[0044] The aerosol-forming substrate may comprise a plant-derived material. The aerosol-forming substrate may comprise tobacco. The aerosol-forming substrate may comprise a tobacco-containing material comprising volatile tobacco flavour compounds which are released from the aerosol-forming substrate upon heating. Alternatively, the aerosol-forming substrate may comprise a non-tobacco-containing material. The aerosol-forming substrate may comprise a homogenised plant-derived material. The aerosol-forming substrate may comprise a homogenised tobacco material. The aerosol-forming substrate may comprise at least one aerosol-forming agent. The aerosol-forming substrate may comprise other additives and ingredients (such as flavourants).

[0045] The liquid reservoir includes an opening, and the heater assembly preferably extends across the opening in the housing. The heater assembly may include an electrically insulating substrate on which the heater element is supported. The electrically insulating substrate may comprise any suitable material, but is preferably a material that can withstand high temperatures (greater than 300 degrees Celsius) and rapid temperature changes. One example of a suitable material is a polyimide film, such as Kapton®. The electrically insulating substrate may have an opening formed therein, and the heater element extends across the opening. The heater assembly may include electrical contacts connected to the conductive filaments.

[0046] According to a second aspect of the present invention, there is provided a cartridge for use in an aerosol generation system, for example an electrically operated aerosol generation system, with a liquid storage portion including a housing for holding a liquid aerosol-forming substrate, where the liquid storage portion includes at least two portions in fluid communication with each other. The first portion of the liquid storage portion includes a first capillary material provided near an opening in the housing and a second capillary material in contact with the first capillary material and spaced from the opening by the first capillary material. The second portion of the liquid storage portion may be substantially empty and suitable for holding a liquid aerosol-forming substrate.

[0047] The cartridge preferably further includes a fluid permeable heater assembly extending across the opening in the housing.

[0048] In an embodiment of the invention, the first portion of the liquid storage portion occupies less than 50% of the volume of the liquid storage portion, preferably between 10% and 30%, more preferably between 15% and 25%, and most preferably about 20%.

[0049] The capillary material extends across the entire cross section of the first portion of the liquid reservoir such that the liquid aerosol-generating substrate cannot flow directly to the opening in the heater assembly or cartridge.

[0050] According to a further aspect of the present invention there is provided an aerosol generation system comprising a cartridge according to the present invention.

[0051] The system may further include an electrical circuit connected to the heater assembly and to the power source, the electrical circuit configured to monitor an electrical resistance of the heater assembly or of one or more filaments of the heater assembly and to control a power supply to the heater assembly dependent on the electrical resistance of the heater assembly or of the one or more filaments.

[0052] The electrical circuitry may comprise a microprocessor, which may be a programmable microprocessor. The electrical circuitry may comprise further electronic components. The electrical circuitry may be configured to regulate the power supply to the heater assembly. Power may be supplied to the heater assembly continuously after activation of the system, or intermittently, such as with each inhalation. Power may be supplied to the heater assembly in the form of current pulses.

[0053] Advantageously, the system includes a power source within the body of the housing. Alternatively, the power source may be another form of charge storage device, such as a capacitor. The power source may require recharging and may have a capacity that allows for storage of sufficient energy for one or more smoking experiences. For example, the power source may have a capacity sufficient to allow for continuous generation of aerosol for approximately six minutes, or a multiple of six minutes, corresponding to the typical time it takes to smoke one conventional cigarette. In another example, the power source may have a capacity sufficient to allow for a predetermined number of puffs, or for discontinuous activation of the heater assembly.

[0054] The aerosol generating system preferably includes a housing. The housing is preferably elongated. The housing may include any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics or composites containing one or more of these materials, or thermoplastics suitable for food or pharmaceutical applications, such as, for example, polypropylene, polyetheretherketone (PEEK) and polyethylene. The material is preferably lightweight and not brittle.

[0055] The aerosol generating system is preferably portable. The aerosol generating system may have a size comparable to a conventional cigar or cigarette. The overall length of the smoking system may be from about 30 mm to about 150 mm. The outer diameter of the smoking system may be from about 5 mm to about 30 mm.

[0056] An aerosol-forming substrate is a substrate capable of releasing a volatile compound capable of forming an aerosol. The volatile compound can be released by heating the aerosol-forming substrate.

[0057] The aerosol-forming substrate may comprise a plant-derived material. The aerosol-forming substrate may comprise tobacco. The aerosol-forming substrate may comprise a tobacco-containing material comprising volatile tobacco flavour compounds which are released from the aerosol-forming substrate upon heating. Alternatively, the aerosol-forming substrate may comprise a non-tobacco-containing material. The aerosol-forming substrate may comprise a homogenised plant-derived material. The aerosol-forming substrate may comprise a homogenised tobacco material. The aerosol-forming substrate may comprise at least one aerosol-forming agent. The aerosol-forming substrate may comprise other additives and ingredients (such as flavourants).

[0058] The system preferably includes a mouthpiece, where the cartridge is inserted into the system with the opening of the cartridge facing away from the mouthpiece.

[0059] In another preferred embodiment, the cartridge is inserted into the system with the cartridge opening facing the mouthpiece. Depending on the situation, one of these cartridge orientations may provide superior performance compared to the other.

[0060] According to a further aspect of the invention, there is provided a cartridge for use in an aerosol generation system comprising a liquid storage portion including a housing for holding a liquid aerosol-forming substrate, the liquid storage portion including a heater assembly, and a capillary material provided in contact with the heater assembly, wherein the average porosity or pore size of a region of the capillary material adjacent the heater assembly is smaller than the average porosity or pore size of a region of the capillary material remote from the heater assembly. The portion of the capillary material in this region may be compressed to reduce its porosity or pore size. The liquid storage portion may include at least two portions in fluid communication with each other, a first portion of the liquid storage portion including the capillary material and a second portion of the liquid storage portion including a reservoir for holding the aerosol-forming substrate in liquid form and supplying liquid to the region of greater porosity or pore size of the capillary material.

[0061] The present invention also relates to a method of manufacturing a cartridge for use in an electrically operated aerosol generating system, comprising the steps of providing a liquid storage portion including a housing having a first part and a second part, providing a heater assembly, disposing a first capillary material within the first part of the liquid storage portion housing such that the first capillary material is provided in direct contact with the heater assembly, and disposing a second capillary material within the first part of the liquid storage portion housing such that the second capillary material is in contact with the first capillary material and is spaced from the heater assembly by the first capillary material, the second part of the liquid storage portion being substantially empty and suitable for holding a liquid aerosol-forming substrate.

[0062] The first capillary material is preferably compressed during or prior to insertion into the housing such that its pore size or porosity is reduced compared to the pore size or porosity in the relaxed state.

[0063] One aspect of the present invention further provides a method of manufacturing a cartridge for use in an aerosol generation system, comprising the steps of providing a liquid storage portion including a housing, providing a heater assembly, and disposing a capillary material within the housing of the liquid storage portion such that the capillary material is provided in direct contact with the heater assembly, wherein the method includes compressing a portion of the capillary material during or prior to disposing the housing such that the porosity or pore size of the portion of the capillary material is reduced.

[0064] The present invention also provides an aerosol generating system, described herein as an electrically operated smoking system.

[0065] The term "substantially planar" filament arrangement is preferably used to mean a filament arrangement that is in the form of a substantially two-dimensional topological manifold. A substantially planar filament arrangement thus extends two-dimensionally along a surface that is substantially larger than the third dimension. In particular, a dimension of the substantially planar filament arrangement in two dimensions within the surface is at least five times larger than the third dimension perpendicular to the surface. An example of a substantially planar filament arrangement is a structure between two substantially parallel surfaces, where the distance between these two surfaces is substantially smaller than the extension within the surface. In some embodiments, the substantially planar filament arrangement is a plane. In other embodiments, the substantially planar filament arrangement is curved along one or more dimensions, for example forming a dome shape or a bridge shape.

[0066] The term "filament" is preferably used to mean an electrical path disposed between two electrical contacts. The filament may optionally branch into several paths or filaments, respectively, or may merge several electrical paths into one path. The filament may be round, square, flat or have any other cross-sectional form. The filament may be arranged in a straight or curved manner.

[0067] The term "filament arrangement" is preferably used to mean an arrangement of one or, preferably, a plurality of filaments. The filament arrangement may for example be a series of filaments arranged parallel to one another. Preferably, the filaments may form a mesh. The mesh may be a woven or non-woven fabric.

[0068] It will be appreciated that, where appropriate, features of one aspect of the invention may be provided in conjunction with other aspects of the invention in any appropriate combination.

[0069] The invention will now be further described, by way of example only, with reference to the accompanying drawings in which: [Brief description of the drawings]

[0070] [Figure 1a] FIG. 1a is a schematic diagram of a system incorporating a cartridge according to an embodiment of the present invention. [Figure 1b] FIG. 1b is a schematic diagram of a system incorporating a cartridge, according to an embodiment of the present invention. [Figure 1c] FIG. 1c is a schematic diagram of a system incorporating a cartridge, according to an embodiment of the present invention. [Figure 1d] FIG. 1d is a schematic diagram of a system incorporating a cartridge, according to an embodiment of the present invention. [Diagram 2] FIG. 2 shows a cartridge with a porous medium according to a first embodiment of the present invention. [Diagram 3]FIG. 3 shows an exploded view of a cartridge similar to that shown in FIG. [Figure 4] FIG. 4 shows a cartridge with a single porous media that is compressed by the shape of the porous material after insertion into the housing. [Diagram 5] FIG. 5 shows a cartridge with a single porous media that is compressed by the shape of the interior surface of the housing after insertion into the housing. [Figure 6] FIG. 6 shows a capillary material rolled into a cylindrical shape and provided with a tubular heater in the center. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0071] Figures la-ld are schematic diagrams of an aerosol generation system including a cartridge according to an embodiment of the present invention. Figure la is a schematic diagram of an aerosol generation device 10 and a separate cartridge 20, which together form the aerosol generation system. In this example, the aerosol generation system is an electrically operated smoking system.

[0072] The cartridge 20 contains an aerosol-forming substrate and is configured to be received in a cavity 18 in the device. The cartridge 20 should be replaceable by a user when the aerosol-forming substrate provided in the cartridge is depleted. Figure 1a shows the cartridge 20 immediately prior to insertion into the device, with arrow 1 in Figure 1a indicating the direction of insertion of the cartridge.

[0073] The aerosol generating device 10 is portable and has a size comparable to a conventional cigar or cigarette. The device 10 includes a body 11 and a mouthpiece portion 12. The body 11 includes a battery 14 (such as a lithium iron phosphate battery), control electronics 16, and a recess 18. The mouthpiece portion 12 is connected to the body 11 by a hinged connection 21 and is movable between an open position shown in Figures 1a-1c and a closed position shown in Figure 1d. The mouthpiece portion 12 is placed in the open position to allow insertion and removal of a cartridge 20, and is placed in the closed position when the system is used to generate aerosol, as described below. The mouthpiece portion includes a number of air inlets 13 and outlets 15. In use, a user draws or inhales through the outlets to draw air from the air inlets 13, through the mouthpiece portion, to the outlets 15, and thereafter into the user's mouth or lungs. An internal baffle 17 is provided to force air flow through the cartridges through the mouthpiece portion 12, as described below.

[0074] The cavity 18 has a circular cross-section and is sized to receive the housing 24 of the cartridge 20. An electrical connector 19 is provided on the side of the cavity 18 for providing electrical connection between the control electronics 16 and battery 14 and corresponding electrical contacts on the cartridge 20.

[0075] Figure 1b shows the system of Figure 1a with a cartridge inserted into cavity 118 and cover 26 removed. In this position, the electrical connector bears against electrical contacts on the cartridge, as described below.

[0076] FIG. 1c shows the system of FIG. 1b with the cover 26 completely removed and the mouthpiece portion 12 moved to the closed position.

[0077] Figure Id shows the system of Figure Ic with the mouthpiece portion 12 in a closed position. The mouthpiece portion 12 is held in the closed position by a clasp mechanism. The mouthpiece portion 12 in the closed position keeps the cartridge in electrical contact with the electrical connector 19 so that a good electrical connection is maintained in use regardless of the orientation of the system. The mouthpiece portion 12 may include an annular resilient element that engages a surface of the cartridge and is compressed between the rigid mouthpiece housing element and the cartridge when the mouthpiece portion 12 is in the closed position. This maintains a good electrical connection regardless of manufacturing tolerances.

[0078] Of course, other mechanisms for maintaining a good electrical connection between the cartridge and the device may alternatively or additionally be employed. For example, the housing 24 of the cartridge 20 may be provided with grooves or threads (not shown) that engage with corresponding threads or grooves (not shown) formed in the walls of the cavity 18. The threaded engagement between the cartridge and the device may be used to ensure proper rotational alignment as well as retention of the cartridge within the cavity and a good electrical connection. The threaded connection may extend less than a half turn of the cartridge, or may extend several turns. Alternatively or additionally, the electrical connector 19 may be biased to contact a contact on the cartridge.

[0079] One of ordinary skill in the art can envision other cartridge designs incorporating the capillary material arrangements of the present disclosure. For example, the cartridge may include a mouthpiece portion, may include multiple heater assemblies, and may have any desired shape. Moreover, the capillary assemblies of the present disclosure may be used in other types of systems previously described, including humidifiers, air fresheners, and other aerosol generating systems.

[0080] The above exemplary embodiments are illustrative and not limiting. In light of the exemplary embodiments discussed above, other embodiments consistent with the above exemplary embodiments will now be apparent to those of ordinary skill in the art.

[0081] The cartridge shown in Figure 2 includes a polypropylene housing 24 with a two-part liquid reservoir. A first part 32 of the liquid reservoir includes a first capillary material 36 and a second capillary material 38. A second part 34 of the liquid reservoir is an empty tank that can be filled or partially filled with a liquid aerosol-generating substrate.

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

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

[0084] Figure 3 is an exploded view of a cartridge similar to that of Figure 2. The cartridge includes a generally circular cylindrical housing 24 including a first part 32 and a second part 34. The first part of the housing 24 includes first and second capillary materials 36, 38 immersed in a liquid aerosol-forming substrate. In this example, the aerosol-forming substrate includes 39 weight percent glycerin, 39 weight percent propylene glycol, 20 weight percent water and flavorings, and 2 weight percent nicotine. The capillary material here is a material that actively transports liquid from one end to the other and may be manufactured from any suitable material. In this example, the capillary material is formed from polyester.

[0085] The housing 24 has an open end in which a heater assembly is secured. The heater assembly includes a base 42 having an opening 44 formed therein, a pair of electrical contacts 48 secured to the base 42 and separated from one another by a gap 40, and a resistive heater element 46 extending over the opening 44 and secured to the electrical contacts 48 on opposite sides of the opening 44.

[0086] The heater assembly is covered by a removable cover 26. The cover 26 comprises a liquid impermeable plastic sheet that is adhered to the heater assembly but is easily removable. Tabs are provided on the sides of the cover to allow a user to grasp the cover when removing it. It will be apparent to one of ordinary skill in the art that although adhesion is described as a method of securing the impermeable plastic sheet to the heater assembly, other methods familiar to those skilled in the art may also be used, including heat sealing or ultrasonic welding, so long as the cover can be easily removed by the consumer.

[0087] FIG. 4 shows an embodiment in which the housing 24 has the shape of a right cylinder with a circular cross section. The first and second capillary materials are made of the same material and are integrally molded as a single continuous piece of capillary material 60 having the shape of a truncated cone. The diameter of the truncated tip of the cone corresponds to the inner diameter of the cylindrical housing. The diameter of the base of the cone is twice as large as the inner diameter of the cylindrical housing. The capillary material 60 is inserted tip-first into the cylindrical housing 24 until the surface of the base of the cone is flush with the front surface of the cylindrical housing. After insertion, the capillary material 40 is compressed, and due to the relative shapes of the capillary material and the cylindrical housing, the compression of the capillary material 60 increases towards the end faces of the cylindrical housing. At the same time, the pore size or porosity of the capillary material decreases such that the pore size or porosity of the capillary material near the end faces of the housing is smaller than the pore size or porosity of the capillary material located at the center of the cylindrical housing. The open end of the cylindrical housing on the right hand side of Figure 4 is provided in a closed state such that the inside of the cylindrical housing forms a tank reservoir for holding the liquid aerosol-generating substrate, and the other end can be provided with a heater assembly as illustrated in Figures 2 and 3.

[0088] FIG. 5 shows an alternative embodiment with a similar effect to the embodiment shown in FIG. 4. In this case, the inner surface of the housing is provided with a conical shape with an internal taper towards one end of the housing 24. Here, the inner diameter of the housing 24 on the left side of FIG. 5 is half the inner diameter of the housing 24 on the right side. Here again, the first and second capillary materials are manufactured from the same material and are integrally molded as a single continuous piece of capillary material 60. The piece of capillary material 60 has a regular cylindrical shape with a circular cross section. The diameter of the cylindrical piece of capillary material 60 corresponds to the inner diameter of the housing 24 on the right side of FIG. 5. The capillary material 60 is inserted into the housing 24 until the end face of the capillary material 60 is flush with the smaller diameter front face of the cylindrical housing, i.e. with the left end face of the housing 24. Again, after insertion, the capillary material 60 is compressed and, due to the relative geometries of the capillary material and the cylindrical housing, the compression of the capillary material 60 increases towards the left end face of the cylindrical housing 24. At the same time, the capillary pore size or porosity decreases such that the pore size or porosity of the capillary material 60 near the end face of the housing is smaller than the pore size or porosity of the capillary material 60 located at the center of the cylindrical housing. Again, the open end of the cylindrical housing on the right side of Figure 5 is provided in a closed state such that the interior of the cylindrical housing forms a tank reservoir for holding the liquid aerosol-generating substrate. The other end face of the housing can be provided with a heater assembly as illustrated in Figures 2 and 3.

[0089] A further embodiment is illustrated in FIG. 6, whereby only the capillary material 50 is shown for use with a cylindrical housing. Again, the first and second capillary materials are formed from a single continuous piece of the same material 50. The capillary material is a rectangular piece of web of capillary material having a thickness of about 25% of the inner diameter of the cylindrical housing of the cartridge. The width of the web of capillary material corresponds to the peripheral circumference of the housing. The length of the web of capillary material is about half the length of the cartridge housing. The web of capillary material is rolled to form a cylindrical shape. An air channel 52 is formed in the center of the rolled capillary material. A tubular fluid-permeable heater element 54 is provided within the air channel 52 such that the heater is in direct contact with the inner surface 56 of the rolled capillary material 50. As the capillary material is rolled, the material portion 50a closer to the central axis of the cylinder is compressed more than the material in the portion 50b located radially outward of the capillary material. Thus, a pore size or porosity gradient is again obtained, but now the pore size or porosity of the capillary material 50 decreases continuously within the capillary material in the direction of the heater element 54. The capillary material is in fluid communication with a liquid reservoir (not shown), where the liquid reservoir is provided within a portion of the housing not occupied by the capillary material. A partition is provided within the housing so that the liquid substrate is not in direct communication with the air flow channel 52.

[0090] It will be appreciated that different methods and configurations are possible to obtain a capillary material with different pore sizes or porosities in different regions. In each example, the region of smaller pore size or porosity is located at one end of the capillary material. Thus, the region of smaller pore size or porosity is located at the heater. Thus, the pore size or porosity gradient enhances capillary action in the material to draw the aerosol-generating substrate liquid to the heater.

[0091] 1. A cartridge for use in an aerosol generating system, comprising: A liquid storage portion, a housing for holding a liquid aerosol-forming substrate, said liquid storage portion having at least two portions in fluid communication with each other, a first portion of said liquid storage portion comprising: a heater assembly; - a first capillary material provided in contact with said heater assembly; - a second capillary material in contact with the first capillary material and spaced from the heater assembly by the first capillary material; A cartridge, wherein a second portion of the liquid storage portion includes a container for holding an aerosol-forming substrate in liquid form, and supplies the liquid to the second capillary material. 2. The cartridge of claim 1, wherein the liquid storage portion includes an opening and the heater assembly extends across the opening in the housing. 3. A cartridge for use in an aerosol generating system, comprising: A liquid storage portion, a housing for holding a liquid aerosol-forming substrate, said housing having an opening; The liquid storage portion includes at least two portions in fluid communication with each other, a first portion of the liquid storage portion having: - a first capillary material provided adjacent the opening of the housing; and - a second capillary material in fluid contact with said first capillary material and spaced from said opening by said first capillary material; A cartridge, wherein a second portion of the liquid storage portion includes a container for holding an aerosol-forming substrate in liquid form, and supplies the liquid to the second capillary material. 4. The cartridge of claim 3, further comprising a fluid permeable heater assembly extending across the opening in the housing. 5. A cartridge described in any one of 1 to 4, wherein the average pore size or porosity of the first capillary material is smaller than the average pore size or porosity of the second capillary material. 6. A cartridge according to any one of 1 to 5, wherein the first capillary material has a fibre or pore size of 0.1 to 50 µm, preferably 0.5 to 10 µm, most preferably about 4 µm. 7. A cartridge according to any one of 1 to 6, wherein the first capillary material has a density of less than 2 g / ml, preferably about 0.5 g / ml. 8. A cartridge according to any one of 1 to 7, wherein the second capillary material has a fibre or pore size of 1 to 100 µm, preferably 15 to 40 µm, most preferably about 25 µm. 9. A cartridge according to 7 or 8, wherein the second capillary material has a density of less than 1 g / ml, preferably between 0.1 and 0.3 g / ml. 10. A cartridge according to any of 1 to 9, wherein the first capillary material or the second capillary material is compressed within the housing such that its effective pore size is reduced. 11. A cartridge according to any one of 1 to 10, wherein the first capillary material and the second capillary material comprise different regions of the same capillary material element. 12. A cartridge as described in any of 1 to 11, wherein the compression of the capillary material when placed within the housing is such that the pore size or porosity of the capillary material decreases continuously towards the heater assembly. 13. A cartridge according to any of 1-12, wherein the first and second capillary materials are formed as a unitary element from a continuous piece of material, thereby increasing the cross-section at one end of the element. 14. A cartridge according to any one of 1 to 13, wherein the interior surface of the housing is in the shape of a regular cylinder having a circular cross-section, and the piece of capillary material is conical. 15. A cartridge as described in any one of 1 to 14, wherein the capillary material has the shape of a regular cylinder with a circular cross-section and the interior surface of the housing includes a tapered portion at an open end, such that the capillary material is compressed by the tapered portion after insertion of the capillary material into the housing. 16. A cartridge for use in an aerosol generating system, comprising: A liquid storage portion, a housing for holding a liquid aerosol-forming substrate, said liquid storage portion comprising: a heater assembly; - a capillary material provided in contact with the heater assembly, wherein an average porosity or pore size of a region of the capillary material adjacent to the heater assembly is less than an average porosity or pore size of a region of the capillary material away from the heater assembly. 17. The cartridge of claim 16, wherein a portion of the capillary material in the region is compressed to reduce its porosity or pore size. 18. The liquid storage portion includes at least two portions in fluid communication with each other; 18. A cartridge as described in 16 or 17, wherein the first portion of the liquid storage portion contains the capillary material and the second portion of the liquid storage portion contains a container for holding an aerosol-forming substrate in liquid form and supplies the liquid to an area of ​​greater porosity or pore size of the capillary material. 19. A method of manufacturing a cartridge for use in an aerosol generating system, comprising: - providing a liquid storage portion including a housing having a first portion and a second portion; - providing a heater assembly; - disposing a first capillary material within the first portion of the housing of the liquid storage portion such that the first capillary material is in direct contact with the heater assembly; - disposing a second capillary material within the first portion of the housing of the liquid storage portion such that the second capillary material contacts the first capillary material and is spaced from the heater assembly by the first capillary material; The method, wherein the second portion of the liquid reservoir is substantially empty and is suitable for holding an aerosol-forming substrate in liquid form. 20. A method according to any of 1-19, wherein a portion of the capillary material is compressed during or prior to insertion into the housing such that the porosity or pore size of the portion of the capillary material is reduced. 21. A method of manufacturing a cartridge for use in an aerosol generating system, comprising: - providing a liquid storage portion including a housing; - providing a heater assembly; - disposing a capillary material within the housing of the liquid storage portion such that the capillary material is in direct contact with the heater assembly; The method includes compressing a portion of the capillary material during or prior to disposing the housing such that the porosity or pore size of the portion of the capillary material is reduced. 22. An aerosol generating system comprising a cartridge described in any one of 1 to 17. 23. The aerosol generation system of claim 22, further comprising a mouthpiece, and wherein the cartridge is inserted into the system with the opening of the cartridge oriented away from or toward the mouthpiece. 24. An aerosol generating system as described in 22 or 23, wherein the system is an electrically operated smoking system.

Claims

1. 1. A cartridge for use in an aerosol generation system, comprising: a housing in which an air flow channel is provided; a liquid reservoir for holding a liquid aerosol-forming substrate; a heater assembly disposed within said air flow channel; a capillary material provided in contact with said heater assembly; Including, the capillary material is wound to form a cylindrical shape; the capillary material includes a first capillary material having a first pore size and a second capillary material having a second pore size, the first capillary material having a higher pyrolysis temperature than the second capillary material; the first capillary material is in contact with the heater assembly; the second capillary material being separated from the heater assembly by the first capillary material; cartridge.

2. The cartridge of claim 1 , wherein the capillary material is a web of rectangular pieces of capillary material.

3. 3. The cartridge of claim 2, wherein the web of capillary material has a thickness that is approximately 25% of the inner diameter of the housing.

4. 4. A cartridge according to claim 2 or 3, wherein the length of the web of capillary material is approximately half the length of the housing of the cartridge.

5. A cartridge according to any one of claims 2 to 4, wherein the web of capillary material has a length that is less than a length of the housing of the cartridge.

6. A cartridge according to any preceding claim, wherein the pore size or porosity of the capillary material decreases continuously within the capillary material in the direction of the heater assembly.

7. The cartridge of any one of claims 1 to 6, wherein the heater assembly is a tubular, fluid permeable heater element.

8. A cartridge according to any preceding claim, wherein the housing is cylindrical.

9. A cartridge according to any preceding claim, wherein the capillary material is in fluid communication with the liquid reservoir.

10. A cartridge according to any preceding claim, wherein the capillary material closer to the heater assembly has a density of less than 1 g / ml.

11. A cartridge according to any preceding claim, wherein the capillary material closer to the heater assembly has a fibre or pore size of 0.5 to 10 μm.

12. A cartridge according to any preceding claim, wherein the capillary material in its radially outermost portion has a density of less than 2 g / ml.

13. A cartridge according to any preceding claim, wherein the capillary material in its radially outermost portion has a fibre or pore size of 15 to 40 μm.

14. A cartridge according to any preceding claim, wherein the capillary material in its radially outermost portion has a density of less than 1 g / ml.

15. A cartridge according to any one of claims 1 to 14, wherein a partition is provided within the housing such that the liquid aerosol-forming substrate is not in direct communication with the air flow channel.

16. 1. A method of manufacturing a cartridge for use in an aerosol generation system, comprising: - providing a housing, in which an air flow channel is provided; - providing a liquid reservoir for holding a liquid aerosol-forming substrate; - placing a heater assembly within said air flow channel; - placing a capillary material in contact with said heater assembly; Including, the capillary material is wound to form a cylindrical shape; the capillary material includes a first capillary material having a first pore size and a second capillary material having a second pore size, the first capillary material having a higher pyrolysis temperature than the second capillary material; the first capillary material is in contact with the heater assembly; the second capillary material being separated from the heater assembly by the first capillary material; method.

17. An aerosol generating system comprising a cartridge according to any one of claims 1 to 15.

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