RU2791975C2 - Aerosol generating system having a liquid permeable heater aseembly and a cartridge for an aerosol generating system having a liquid permeable heater aseembly - Google Patents

Abstract

FIELD: aerosol generating system.

SUBSTANCE: system has a liquid permeable heater assembly, a cartridge for the aerosol generating system and a method for manufacturing the cartridge. The aerosol generating system comprises a liquid storage portion comprising a rigid body holding an aerosol generating liquid substrate, the housing having an opening, and a liquid-permeable heater assembly comprising a plurality of electrically conductive filaments, the liquid-permeable heater assembly being attached to the body and extending across the body opening. Providing a heater assembly that extends across the opening of the liquid storage portion provides a robust design that is relatively simple to manufacture. The heater assembly is flat for easy manufacturing.

EFFECT: providing a large area of contact between the heater assembly and the liquid substrate forming the aerosol.

23 cl, 29 dwg

Description

The present invention relates to aerosol generating systems that include a heater assembly that is suitable for vaporizing a liquid. In particular, the invention relates to hand held aerosol generating systems such as electrically controlled smoking systems.

One type of aerosol generating system is an electrically controlled smoking system. Hand-held electrically controlled smoking systems are known, consisting of a device part containing a battery and control electronics, and a cartridge part containing an aerosol-forming substrate supply source and an electrically controlled vaporizer. A cartridge containing both an aerosolizing substrate supply and an evaporator is sometimes referred to as a "nebulizer cartridge". The evaporator typically comprises a coil of heater wire wound around an elongated wick impregnated with an aerosol-forming liquid substrate. The cartridge portion typically includes not only a source of aerosol-forming substrate and an electrically controlled vaporizer, but also a mouthpiece through which, in use, the user puffs to draw the aerosol into their mouth.

However, this arrangement has the disadvantage that the cartridges are relatively expensive to manufacture. This is because the manufacture of the wick and spool assembly is complex. Also, the electrical contacts between the wire coil of the heater and the electrical contacts through which electrical current is supplied from the device part must be carefully processed during manufacture. In addition, these cartridges include a mouthpiece to protect the flexible wick and coil assembly during shipping. But the inclusion of a complete and reliable mouthpiece in each cartridge means that each cartridge will have a high material cost.

It is necessary to provide a heater assembly suitable for an aerosol generating system such as a hand-held electrically controlled smoking system that is inexpensive to manufacture and reliable. Additionally, a heater assembly must be provided that is more efficient than previous heater assemblies in aerosol generating systems.

In a first aspect, an aerosol generating system is provided, including:

a liquid storage portion comprising a housing holding a liquid substrate forming an aerosol, the housing having an opening; And

a liquid-permeable heater assembly comprising a plurality of electrically conductive filaments, the liquid-permeable heater assembly being attached to the housing and extending across the opening of the housing.

Providing a heater assembly that extends across the opening of the liquid storage portion provides a robust structure that is relatively easy to manufacture. This arrangement provides a large area of contact between the heater assembly and the aerosol-forming liquid substrate. The housing may be a rigid housing. In this context, "rigid enclosure" means a self-supporting enclosure. The rigid housing of the liquid storage portion preferably provides mechanical support for the heater assembly. The heater assembly may be substantially flat, allowing for ease of manufacture. In this context, "substantially flat" means formed originally in one plane and not wrapped around or otherwise adapted to conform to a curved or otherwise non-planar shape. Geometrically, the term "substantially flat" arrangement of electrically conductive filaments is used to refer to an arrangement of electrically conductive filaments that has the shape of a substantially two-dimensional topological manifold. Thus, the substantially planar arrangement of electrically conductive filaments extends substantially farther along the surface in two dimensions than in the third dimension. In particular, the dimensions of the substantially flat arrangement of filaments in two dimensions within the surface are at least 5 times the dimension in the third dimension perpendicular to the surface. An example of a substantially planar arrangement of filaments is a structure between two substantially imaginary parallel surfaces, wherein the distance between these two imaginary surfaces is substantially less than the extent within the planes. In some embodiments, the substantially flat arrangement of filaments is planar. In other embodiments, the substantially flat arrangement of filaments is curved along one or more dimensions, such as forming a domed shape or a bridge shape.

The term "filament" is used throughout this specification to refer to an electrical path located between two electrical contacts. The thread may arbitrarily fork and split into multiple paths or threads, respectively, or several electrical paths may converge into one path. The thread may have a round, square, flat or any other cross section. The thread may be arranged in a straight or curved form.

The term "arrangement of threads" is used throughout the present description to refer to the arrangement of one or preferably multiple threads. The arrangement of threads may be a matrix of threads, for example, arranged parallel to each other. Preferably, the threads may form a network. The mesh may be woven or non-woven.

The plate heater assembly can be easily machined during manufacture and provides a robust design.

The system may advantageously comprise a device and a cartridge that is removably coupled to the device, wherein a liquid storage portion and a heater assembly are provided in the cartridge and the device comprises a power source. The production of the cartridge can be low cost, reliable and mass produced. In this context, a cartridge "removably coupled" to a device means that the cartridge and device can be connected and detached from each other without significant damage to both the device and the cartridge.

The system may be an electrically controlled smoking system.

Electrically conductive threads may be in the same plane. The plate heater assembly can be easily machined during manufacture and provides a robust design.

The electrically conductive filaments may form spaces between each other, and these spaces may have a width of 10 µm to 100 µm. Preferably, the filaments create a capillary effect in the interstices so that in use the liquid to be vaporized is drawn into the interstices, increasing the area of contact between the heater assembly and the liquid.

The electrically conductive filaments can form a grid of 160 to 600 US mesh (+/- 10%) (ie 160 to 600 threads per inch (+/- 10%)). The width of the gaps is preferably between 75 µm and 25 µm. The percentage of open area of the mesh, which is the ratio of the area of the gaps to the total area of the mesh, is preferably 25% to 56%. The mesh may be formed using various types of wicker or lattice structures. Alternatively, the electrically conductive filaments consist of an array of filaments arranged parallel to each other.

The network, matrix, or material of electrically conductive filaments may also be characterized by its ability to retain liquid, as is well known in the art.

The electrically 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 circular cross section or may have a flattened cross section.

The area of the grid, matrix or material of electrically conductive filaments can be small, preferably less than or equal to 25 mm ² , allowing it to be incorporated into a hand held system. The grid, matrix or material of electrically conductive threads may, for example, have a rectangular shape and dimensions of 5 mm by 2 mm. Preferably, the grid or matrix of electrically conductive filaments covers an area of 10% to 50% of the area of the heater assembly. More preferably, the grid or matrix of electrically conductive filaments covers an area of 15% to 25% of the area of the heater assembly. The use of grid, matrix or material of electrically conductive filaments, occupying 10% and 50% of the area, or not more than 25 mm ² , reduces the amount of total power required to heat the grid, matrix or material of electrically conductive filaments, while still providing sufficient contact of the grid, matrix or material of electrically conductive filaments with the liquid provided by one or more evaporable capillary materials.

The heater filaments may be formed by etching a sheet material such as foil. This may be particularly advantageous if the heater assembly comprises an array of parallel filaments. If the heater assembly comprises a mesh or filament material, the filaments may be formed separately and tied together. Alternatively, the heater filaments may be stamped from an electrically conductive foil such as stainless steel.

The heater filament assemblies may be formed from any material with suitable electrical properties. Suitable materials include, but are not limited to: semiconductors such as doped ceramics, electrically "conductive" ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys, and composite materials made from ceramic material and metal material. Such composite materials may contain alloyed or unalloyed ceramics. Examples of suitable doped ceramics include doped silicon carbides. Examples of suitable metals include titanium, zirconium, tantalum and the platinum group metals. Examples of suitable metal alloys include stainless steel, constantan, nickel, cobalt, chromium, aluminum, titanium, zirconium, hafnium, niobium, molybdenum, tantalum, tungsten, tin, gallium, manganese - and ferrous alloys, as well as superalloys based on nickel, iron, cobalt, stainless steel, Timetal®, alloys based on iron and aluminum and alloys based on iron, manganese and aluminum. Timetal® is a registered trademark of Titanium Metals Corporation. The threads may be covered with one or more insulators. Preferred materials for electrically conductive filaments are 304, 316, 304L, 316L stainless steel and graphite. In addition, the arrangement of the electrically conductive filaments may include combinations of the materials described above. The combination of materials can also be used to improve the resistance management of a substantially flat arrangement of filaments. For example, high self-resistance materials can be combined with low self-resistance materials. This may provide an advantage if one of the materials is preferred for other reasons, such as price, workability, or other physical and chemical parameters. Advantageously, a substantially flat arrangement of increased resistance filaments reduces parasitic losses. Advantageously, high resistivity heaters provide more efficient use of battery power. The energy of the battery is proportionally divided into the energy lost in the printed circuit board and contacts, and the energy supplied to the arrangement of electrically conductive filaments. Thus, the energy available for the arrangement of electrically conductive filaments in the heater is higher the higher the resistance of the arrangement of electrically conductive filaments.

In an exemplary embodiment, the substantially flat arrangement of filaments may be composed of two types of metal wires that form a wire mesh. In such an embodiment, highly resistive wires are preferably oriented in the direction of current flow, such as wires made from a chromium-nickel alloy. Accordingly, in this embodiment, the low resistance wires are arranged substantially perpendicular to the high electrical resistance wires. For example, the low resistance wires may be stainless steel wires. Preferably, the relatively cheaper low resistance wires support the high electrical resistance wires. In addition, wires with high electrical resistance tend to be less flexible than stainless steel wires and thus can be easily made into thin wires. Therefore, in such an advantageous embodiment of the invention, relatively thick high electrical resistance wires are combined with thin, low electrical resistance stainless steel wires, with the added benefit that thinner stainless steel wires improve wetting of the substantially flat arrangement of filaments due to increased capillary forces.

Alternatively, the arrangement of electrically conductive filaments may be formed from a fabric of carbon filaments. Carbon filament fabric has the advantage that it is generally more cost effective than high resistivity metal heaters. Also, carbon filament fabric is generally more flexible than metal mesh. Yet another advantage is that contact between the carbon filament fabric and a transport medium, such as a high release material, can be well maintained during assembly of the liquid-pervious heater assembly.

Reliable contact between the liquid-permeable heater assembly and a transport medium, such as a capillary transport medium such as a wick made from fibers or a porous ceramic material, improves continuous wetting of the liquid-permeable heater assembly. This advantageously reduces the possibility of overheating of the electrically conductive filament arrangement and spontaneous thermal decomposition of the liquid.

The heater assembly may include an electrically insulating substrate on which the filaments are supported. The electrically insulating substrate may comprise any suitable material, and it is preferred that the material be capable of withstanding high temperatures (above 300 degrees Celsius) and rapid temperature changes. An example of a suitable material is a polyimide film such as Kapton®. The electrically insulating substrate may have an opening formed therein, with electrically conductive threads extending across the opening. The heater assembly may include electrical contacts connected to electrically conductive filaments. For example, electrical contacts may be glued, welded, or mechanically attached to an arrangement of electrically conductive filaments. Alternatively, an arrangement of electrically conductive filaments may be printed on an electrically insulating substrate, for example using metallic inks. In such an arrangement, the electrically insulating substrate is preferably a porous material, so that the arrangement of electrically conductive filaments can be applied directly to the surface of the porous material. Preferably, in such an embodiment, the porosity of the substrate functions as an "opening" of the electrically insulating substrate through which liquid can be drawn in the direction of the arrangement of the electrically conductive filaments.

The electrical resistance of the grid, matrix or material of electrically conductive filaments of the heater element is preferably between 0.3 ohms and 4 ohms. More preferably, the electrical resistance of the mesh, matrix, or material of electrically conductive filaments is between 0.5 ohms and 3 ohms, and even more preferably about 1 ohm. The electrical resistance of the grid, matrix or material of electrically conductive threads is preferably at least an order of magnitude and more preferably at least two orders of magnitude greater than the electrical resistance of the contact parts. This ensures that the heat generated by passing the current through the heater element is localized on a grid or matrix of electrically conductive filaments. The low overall resistance of the heater element is advantageous if the system is powered by a battery. The low resistance, high current system allows high power to be delivered to the heater element. This ensures that the electrically conductive filaments are rapidly heated by the heater element to the required temperature.

The first and second parts of the electrically conductive contact may be directly attached to the electrically conductive threads. The contact portions may be located between the electrically conductive filaments and the electrically insulating substrate. For example, the contact portions may be formed from copper foil which is deposited on an insulating substrate. The contact parts can also be more easily bonded to the filaments than the insulating substrate.

Alternatively, the first and second parts of the electrically conductive contact may be integral with the electrically conductive threads. For example, a heater element may be formed by etching a conductive sheet to provide a plurality of filaments between two contact portions.

The heater assembly may comprise at least one filament made from a first material and at least one filament made from a second material different from the first material. This may be advantageous for electrical or mechanical reasons. For example, one or more filaments may be formed from a material whose resistance varies greatly with temperature, such as an alloy of iron and aluminum. This ensures that the resistance value of the filaments is used to detect temperature or temperature changes. This can be used in a puff detection system and to control the temperature of the heater to keep it within the desired temperature range. Abrupt temperature changes can also be used as indicators to detect changes in airflow downstream of the heater assembly as a result of user puffing from the system.

The housing of the liquid storage part preferably comprises a capillary material. A capillary material is a material that actively transfers fluid from one end of the material to the other. The capillary material is advantageously oriented in the housing so as to transfer fluid to the heater assembly.

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 contain a plurality of fibers or filaments or other thin tubes with channels. The fibers or filaments may be generally aligned to transfer fluid to the heater. Alternatively, the capillary material may comprise a sponge-like or foam-like material. The structure of the capillary material forms many small channels or tubes through which liquid can be transported by capillary action. The capillary material may comprise any suitable material or combination of materials. Examples of suitable materials are sponge or foam material, ceramic or graphite based materials in the form of fibers or sintered powders, foamed metal or plastic material, fibrous material, for example, made from twisted 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 capillarity and porosity so as to be used with liquids of different physical properties. A liquid has physical properties including, but not limited to, viscosity, surface tension, density, thermal conductivity, boiling point, and vapor pressure, which allow the liquid to be transported through a capillary device by capillary action.

The capillary material may be in contact with electrically conductive filaments. The capillary material may extend within the spaces between the filaments. The heater assembly can draw an aerosol-forming liquid substrate into the interstices by capillary action. The capillary material may be in contact with the electrically conductive filaments for substantially the entire length of the opening. In one embodiment, the capillary material in contact with the arrangement of electrically conductive filaments may be a filamentous wick. Preferably, the filamentous wick has a first section and a second section, the first section being substantially perpendicular to the arrangement of the electrically conductive filaments, reaching the liquid storage portion of the cartridge. Preferably, the second section of the filamentous wick is positioned substantially parallel to the arrangement of the electrically conductive filaments. Preferably, the threads of the threaded wick are continuous from the first section of the threaded wick to the second section of the threaded wick. This allows rapid transport of liquid in the direction of the arrangement of electrically conductive threads through the first section of the filamentous wick and at the same time rapid distribution throughout the arrangement of electrically conductive filaments through the second section of the filamentous wick. This advantageously ensures continuous wetting of the entire arrangement of electrically conductive filaments. Continuous wetting can prevent overheating and spontaneous liquid decomposition due to overheating.

Preferably, the arrangement of electrically conductive filaments comprises at least a plurality of filaments made from alloys or coated with films that are sensitive to the presence of a liquid, such as water. This provides for the detection of wetting of an arrangement of electrically conductive filaments, for example by connecting the sensing wires to a circuit that monitors the electrical resistance of the wires and suspends the heater or lowers the current if a dry contact boundary is detected. This advantageously improves the safety of the aerosol generating system. In one embodiment, the filaments that are used to detect wetting are stainless steel wires that are coated with indium nitride (InN) or alumina (Al ₂ O ₃ ) films. When used, a liquid such as water reduces the number of electrons on such film surfaces and maintains a high electrical resistivity of the film until the film surface is dry. Then the resistivity drops rapidly. The drop in resistivity is detected by the connected electrical circuit.

Advantageously, the heater assembly and the capillary material may be sized to have approximately the same area. In this context, "approximately" means that the area of the heater assembly may exceed the area of the capillary material by 0-15%. The shape of the heater assembly may also be similar to that of the capillary material such that the heater assembly and material substantially overlap. If the heater assembly and the material are substantially similar in size and shape, manufacturing can be simplified and reliability of the manufacturing process improved. As discussed below, the capillary material may include two or more capillary materials, including one or more layers of capillary material, in direct contact with a network, matrix, or electrically conductive filament material of the heater assembly to promote aerosol generation. Capillary materials may include the materials described herein.

At least one of the capillary materials may have sufficient volume to ensure that there is a minimum amount of liquid in said capillary material to prevent "dry heat" that occurs if insufficient liquid is provided to the capillary material in contact with the mesh, matrix, or material of electrically conductive threads. A minimum volume of said capillary material can be provided to provide 20-40 puffs by the user. The average volume of liquid evaporated during a puff, lasting from 1 to 4 seconds, is usually 1-4 mg of liquid. Thus, providing at least one capillary material having a volume to hold 20-160 mg of a liquid containing an aerosol-forming liquid substrate can prevent dry heating.

The housing may contain two or more different capillary materials, wherein the first capillary material in contact with the heater element has a higher thermal decomposition temperature, and the second capillary material in contact with the first capillary material, but not in contact with the element heater, has a lower thermal decomposition temperature. The first capillary material effectively acts as a spacer separating the heater element from the second capillary material such that the second capillary material is not exposed to temperatures in excess of its thermal decomposition temperature. In this context, "thermal decomposition temperature" means the temperature at which the material begins to decompose and lose mass as a result of the formation of gaseous products. The second capillary material may advantageously occupy a larger volume than the first capillary material and may hold a larger amount of aerosol forming substrate than the first capillary material. The second capillary material may have better capillary properties than the first capillary material. The second capillary material may be cheaper than the first capillary material. The second capillary material may be polypropylene.

The first capillary material may separate the heater assembly from the second capillary material by at least 1.5 mm, and preferably 1.5 mm to 2 mm, to provide sufficient temperature reduction downstream of the first capillary material.

The liquid storage part may be located on the first side of the electrically conductive filaments, and the air flow channel is located on the opposite side of the electrically conductive filaments relative to the liquid storage part, so that the air flow after the electrically conductive filaments entrains the vaporized liquid substrate forming an aerosol.

In addition to an electrical heater assembly that is adjacent to or in contact with the fluid transport medium, the aerosol generating system may include at least one additional electrical heater assembly in operative communication with the fluid storage portion. An additional electrical heater assembly in operative communication with the fluid storage portion may increase the flow rate of fluid from the fluid storage portion. This is particularly advantageous if the liquid storage portion contains a high-retention medium in which liquid is stored. It is advantageous to use a high liquid storage medium in the liquid storage part. For example, the use of a high retention medium reduces the chance of leakage. In the event of a breakage or crack in the cartridge body, spilled liquid may lead to inadvertent contact with active electrical components and biological tissue. However, since liquid is attracted by wettability forces to the surface of the high-retention medium, significant liquid leakage is less likely compared to free liquid filled tanks in the event of mechanical cracks in the cartridge body. However, since the high retention medium will generally retain at least a portion of the liquid, it in turn will not be available to create an aerosol. Advantageously, providing additional heating units increases the flow rate of the liquid storage part, that is, the ratio between the amount of liquid removed from the liquid storage part and the amount of liquid that cannot be removed from the liquid storage part.

Preferably, the additional electrical heater assembly is located adjacent to areas of high retention media that are less likely to be depleted by the primary electrical heater assembly, such as most of the areas of high retention media furthest from the first electrical heater assembly. Preferably, the additional electrical heater assembly is located on the bottom wall of the housing, i.e., on the wall opposite the electrical heater assembly. As an alternative or addition, an additional electrical heater assembly is located on the side wall of the housing.

Preferably, the additional electrical heater assembly is controlled to be activated only when needed, for example, if a decrease in fluid flow is detected. For example, an additional electrical heater assembly may be activated upon detection of a decrease in wetting level of the first electrical heater assembly.

Alternatively or in addition, the housing has an inner non-cylindrical, eg conical shape such that the wider section of the inner non-cylindrical shape points towards the electric heater assembly and the inner smaller section continues in the opposite direction. This makes the gravitational forces acting on the liquid more relevant to move the liquid towards the electric heater assembly, particularly if the aerosol generating system is in a substantially horizontal orientation. The horizontal orientation is an orientation in which the electrical heater assembly is substantially at the same vertical level as the liquid storage portion. This horizontal orientation is typical during use of an aerosol generating system.

Alternatively or in addition, a cartridge comprising an electrical heater assembly and a housing is positioned in the aerosol generating system such that the electrical heater assembly is positioned across the opening of the housing on the side of the liquid storage portion away from the mouthpiece of the aerosol generating system. This may be beneficial to the aerosol flow path within the aerosol generating system. For example, in a vertical arrangement of an aerosol generating system, the mouthpiece is on top and the body is in an inverted position, i.e. the liquid is located above the electric heater assembly. In such an embodiment, instead of resisting gravitational forces, gravitational forces assist capillary forces to move the liquid towards the electrical heater assembly.

Preferably, the housing comprises two elements, the first element being a lid and the second element being a reservoir, with the lid covering the reservoir. Preferably, in accordance with the invention, the cover contains or is in direct contact with the heater assembly. Preferably, the reservoir contains a liquid and, if present, a first capillary material or both the first and second capillary materials. Preferably, the lid material is made from a high thermal decomposition temperature material such as polyether ether ketone (PEEK) or Kapton®. Preferably, the lid is sized to separate the reservoir from the heater assembly by at least 1.5 mm, and preferably 1.5 mm to 2 mm, to provide sufficient temperature reduction behind the lid. Advantageously, in such an embodiment, the reservoir material may be made from a more cost-effective material with a lower thermal decomposition temperature, such as, for example, polyethylene or polypropylene.

The air inlet may, for example, be located in the main body of the system. Ambient air is directed into the system, extends the heating element at the distal end of the cartridge, and entrains the aerosol formed by heating the aerosol-forming substrate in the cartridge. Air containing the aerosol may then be directed along the cartridge between the cartridge body and the main body to the downstream end of the system where it mixes with ambient air from the secondary flow path (either before or upon reaching the downstream end).

The inlet of the second channel located in the area of the distal end of the cartridge body can also be provided in an alternative system in which the heating element is located at the proximal end of the cartridge. The second flow path may not only extend outward of the cartridge, but also through the cartridge. Ambient air then enters the cartridge through the semi-open cartridge wall, continues through the cartridge, and exits the cartridge by passing through a heating element located at the proximal end of the cartridge. Therefore, the ambient air can continue through the aerosol-forming substrate or through one or more channels located in the solid aerosol-forming substrate, such that the ambient air does not continue through the substrate itself, but continues through the channels adjacent to the substrate.

To allow ambient air to enter the cartridge, at least one semi-open inlet is provided on the wall of the cartridge body, preferably the wall opposite the heating element, preferably the bottom wall. The half-open inlet allows air to enter the cartridge, but neither air nor liquid exits the cartridge through the half-open inlet. The semi-open inlet can be, for example, a semi-permeable membrane that is only permeable to air in one direction but impermeable to air and fluid in the opposite direction. The semi-open inlet may also be, for example, a one-way valve. Preferably, semi-open inlets allow air to pass through the inlet only when certain conditions are met, such as a minimum pressure drop in the cartridge or the volume of air passing through the valve or membrane.

Such one-way valves may be, for example, commercially available valves such as those used in medical devices, such as LMS Mediflow One-Way, LMS SureFlow One-Way, or LMS Check Valves (cross diaphragms). Suitable membranes for use with a cartridge having an airflow through the cartridge are, for example, vented membranes as used in medical devices, such as Qosina Ref. 11066, vented cap with hydrophobic filter or valves used in baby bottles. These valves and membranes can be made from any material suitable for electrically heated smoking system applications. Materials suitable for medical devices and FDA approved materials can be used; for example, graphene, which has very high mechanical resistance and thermal stability over a wide temperature range. Preferably, the valves are made of a soft resilient material to support a liquid-tight inclusion of one or more valves in the container body wall.

The passage of ambient air through the substrate promotes aerosol formation by the aerosol-forming substrate. During puffing, a pressure drop occurs in the cartridge, which can activate half-open inlets. The ambient air then continues through the cartridge, preferably a high retention or high release material (HRM) or liquid, and crosses the heating element, thereby creating and maintaining aerosol formation from the liquid when the heating element sufficiently heats the liquid. In addition, due to the reduction in pressure generated during the puff, the supply of liquid in the transport material, such as capillary material, to the heating element may be limited. The flow of ambient air through the cartridge can equalize the pressure differences within the cartridge and therefore promote free capillary action towards the heating element.

As an addition or alternative, a semi-open inlet may also be provided in one or more side walls of the cartridge body. The semi-open inlets in the sidewalls provide a lateral flow of air into the cartridge towards the open upper end of the cartridge body where the heating element is located. Preferably, lateral air currents pass through the aerosol-forming substrate.

The system may further comprise an electrical circuit connected to the heater assembly and an electrical power source, wherein the electrical circuit is configured to control the electrical resistance of the heater assembly or one or more filaments of the heater assembly, and to control the supply of power to the heater assembly, depending on the electrical resistance of the heater assembly or one or more filaments.

The circuitry may include a microprocessor, which may be a programmable microprocessor. The electrical circuit may contain additional electronic components. The electrical circuitry may be configured to control the power supply to the heater assembly. Power may be supplied to the heater assembly continuously after system activation, or may be supplied intermittently, such as from puff to puff. Power may be supplied to the heater assembly in the form of electrical current pulses.

The system advantageously includes a power source, typically a battery, within the main housing portion. Alternatively, the power supply may be another type of charge storage device, such as a capacitor. The power supply may need to be recharged and may have the capacity to store enough energy for one or more smoking sessions; for example, the power supply may have sufficient capacity to allow the aerosol to be continuously generated for about six minutes, or for a period in multiples of six minutes. In another example, the power supply may have sufficient capacity to allow for a given number of puffs or individual activations of the heater assembly.

Preferably, the aerosol generating system comprises a housing. Preferably, the body is elongated. The housing may comprise any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics or composite materials containing one or more of these materials, or thermoplastics suitable for use in the food or pharmaceutical industry, such as polypropylene, polyether ether ketone (PEEK) and polyethylene. Preferably, the material is lightweight and non-fragile.

Preferably, the aerosol generating system is portable. The aerosol generating system may be of a size comparable to that of a conventional cigar or cigarette. The smoking system may have an overall length of from about 30 mm to about 150 mm. The smoking system may have an outer diameter of from about 5 mm to about 30 mm.

An aerosol-forming substrate is a substrate capable of releasing volatile compounds that can form an aerosol. Volatile compounds can be released by heating the aerosol-forming substrate.

The aerosol-forming substrate may contain material of vegetable origin. The aerosol forming substrate may contain tobacco. The aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavor compounds that are released from the aerosol-forming substrate upon heating. The aerosol forming substrate may alternatively comprise a non-tobacco material. The aerosol forming substrate may contain homogenized plant material. The aerosol forming substrate may comprise homogenized tobacco material. The aerosol generating substrate may contain at least one aerosol generating agent. The aerosol forming substrate may contain other additives and ingredients such as flavors.

In a second aspect, a cartridge is provided for use in an electrically controlled aerosol generating system, comprising:

a liquid storage portion comprising a housing holding a liquid substrate forming an aerosol, the housing having an opening; And

a liquid-permeable heater assembly comprising a plurality of electrically conductive filaments, wherein the liquid-permeable heater assembly extends across the body opening of the liquid storage portion.

The cartridge with this design can be rigid, reliable and low cost. The heater assembly may be substantially flat without the need for any coiling of the heater wire around the capillary wick.

Electrically conductive threads may be in the same plane. The plate heater assembly can be easily machined during manufacture and provides a robust design.

The electrically conductive filaments may form spaces between each other, and these spaces may have a width of 10 µm to 100 µm. Preferably, the filaments create a capillary effect in the interstices so that in use the liquid to be vaporized is drawn into the interstices, increasing the area of contact between the heater assembly and the liquid.

The electrically conductive filaments can form a grid of 160 to 600 US mesh (+/- 10%) (ie, 160 to 600 threads per inch (+/- 10%)). The gap width is preferably 75 µm to 25 µm. The percentage of open area of the mesh, which is the ratio of the area of the gaps to the total area of the mesh, is preferably 25 to 56%. The mesh may be formed using various types of wicker or lattice structures. Alternatively, the electrically conductive filaments consist of an array of filaments arranged parallel to each other.

The electrically 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 circular cross section or may have a flattened cross section. The heater filaments may be formed by etching a sheet material such as foil. This may be particularly advantageous if the heater assembly comprises an array of parallel filaments. If the heater assembly comprises a mesh or filament material, the filaments may be formed separately and tied together.

The area of the grid, matrix or material of electrically conductive filaments can be small, preferably less than or equal to 25 mm ² , allowing it to be incorporated into a hand held system. The grid, matrix or material of electrically conductive threads may, for example, have a rectangular shape and dimensions of 5 mm by 2 mm. Preferably, the grid or matrix of electrically conductive filaments covers an area of 10% to 50% of the area of the heater assembly. More preferably, the grid or matrix of electrically conductive filaments covers an area of 15 to 25% of the area of the heater assembly.

The electrically conductive filaments may comprise any suitable electrically conductive material. Preferred materials for electrically conductive filaments are 304, 316, 304L, 316L stainless steel and graphite.

The electrical resistance of the grid, matrix or material of electrically conductive filaments of the heater element is preferably 0.3 to 4 ohms. More preferably, the electrical resistance of the grid, matrix, or material of electrically conductive filaments is between 0.5 and 3 ohms, and even more preferably about 1 ohm. The electrical resistance of the grid, matrix or material of electrically conductive threads is preferably at least an order of magnitude and more preferably at least two orders of magnitude greater than the electrical resistance of the contact parts.

The housing of the liquid storage part may comprise a capillary material as described in relation to the first aspect. The capillary material may be oriented in the housing so as to transfer fluid to the heater assembly. The capillary material may be in contact with the heater assembly. The capillary material may extend within the spaces between the filaments.

As described in relation 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 higher thermal decomposition temperature, and the second capillary material in contact with the first capillary material, but not in contact with the heater element has a lower thermal decomposition temperature. The first capillary material may separate the heater assembly from the second capillary material by at least 1.5 mm and preferably 1.5 to 2 mm to provide sufficient temperature reduction downstream of the first capillary material.

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

The heater assembly may comprise an electrically insulating substrate on which the filaments are supported, with the filaments extending across a hole formed in the substrate. The electrically insulating substrate may comprise any suitable material, and it is preferred that this material be 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®.

The heater assembly may include an electrically conductive contact in contact with a plurality of filaments. An electrically conductive contact may be provided between the body of the liquid storage part and the electrically insulating substrate. An electrically conductive contact may be provided between the filaments and the electrically insulating substrate. The hole may be formed in the electrically insulating layer, and the cartridge may include two electrically conductive contacts located on opposite sides of the hole relative to each other.

Preferably, the electrically conductive contact is accessed from the outside of the cartridge. The heater assembly may extend in a lateral plane and the electrically conductive contact may extend sideways outside of the body of the liquid storage portion. The cartridge can then be configured to be inserted into the aerosol generating device in a direction perpendicular to the side plane, whereby an electrically conductive contact comes into contact with an electrical contact on the device.

The body of the liquid storage part may be substantially cylindrical in shape with an opening located at one end of the cylinder. The body of the liquid storage part may have a substantially circular cross section.

The heater assembly is advantageously coated with a release liner or seal prior to use. A coating or seal can protect the substrate from degradation during storage and transport.

In a preferred embodiment, the cartridge does not contain an electrical power source.

In a third aspect, a method is provided for manufacturing a cartridge for use in an electrically controlled aerosol generating system, comprising:

providing a liquid storage portion comprising a housing having an opening;

filling the liquid storage portion with an aerosol-forming liquid substrate; And

attaching a liquid-permeable heater assembly comprising a plurality of electrically conductive filaments to the liquid storage part, the liquid-permeable heater assembly extending across the body opening of the liquid storage part.

The step of filling the liquid storage part may be performed before or after the step of attaching the heater assembly to the liquid storage part.

The attachment step may, for example, include thermal bonding, bonding or welding of the heater assembly and the fluid storage portion. The liquid storage portion may contain capillary material.

The features described in relation to one aspect can be equally applied to other aspects of the invention. In particular, the features described with respect to the first aspect can be equally applied to the second aspect and the third aspect.

In this context, "electrically conductive" means formed from a material having a resistivity of 1×10 ^-4 ohm⋅m or less. In this context, "electrically insulating" means formed from a material having a resistivity of 1×10 ⁴ ohm⋅m or more. In this context, "liquid-permeable" in relation to the heater assembly means that the aerosol-forming substrate, in the gaseous phase and possibly in the liquid phase, can easily be continued through the heater assembly.

Embodiments of the invention will now be described solely by way of example with reference to the accompanying drawings, in which:

in fig. 1a-1d show schematic illustrations of a system including a cartridge, in accordance with an embodiment of the invention;

in fig. 2 is a schematic illustration of the locking mechanism for the mouthpiece of the system shown in FIG. 1;

in fig. 3 is an exploded view of the cartridge shown in FIG. 1a-1d;

in fig. 4 is an exploded view of an alternative cartridge for use in the system as shown in FIG. 1a-1d;

in fig. 5a is a bottom perspective view of the cartridge shown in FIG. 2;

in fig. 5b is a top perspective view of the cartridge shown in FIG. 2, with the coating removed;

in fig. 6 is a detailed view of the heater assembly used in the cartridge shown in FIG. 2;

in fig. 7 is a detailed view of an alternative heater assembly that may be used in the cartridge shown in FIG. 2;

in fig. 8 is a detailed view of an optional alternative heater assembly that can be used in the cartridge shown in FIG. 2;

in fig. 9 is a detailed view of yet another optional alternative heater assembly that can be used in the cartridge shown in FIG. 2;

in fig. 10 shows a detailed view of an alternative mechanism for making electrical contact between the device and the heater assembly;

in fig. 11a-11b illustrate some forms of cartridge housing that can be used to ensure proper alignment of the cartridge in the device;

in fig. 12a is a detailed view of the heater filaments showing the meniscus of the aerosol forming liquid substrate between the filaments;

in fig. 12b is a detailed view of the heater filaments showing a meniscus of aerosol forming liquid substrate between the filaments and capillary material passing between the filaments;

in fig. 13a, 13b and 13c illustrate alternative methods of making a heater assembly in accordance with the invention; And

in fig. 14 illustrates an alternative construction of a liquid storage portion including a heater assembly.

In FIG. 15a and 15b illustrate further alternative embodiments of the liquid storage portion including the heater assembly.

In FIG. 16 illustrates an alternate embodiment of airflow and cartridge orientation relative to the aerosol generating device;

In FIG. 17 shows a cross-sectional view of the high retention material cartridge system and the passage of air through the HRM;

in fig. 18 shows a cross-sectional view of yet another high retention material cartridge system and the passage of air through the cartridge;

in fig. 19 is an exploded view of the cartridge system shown in FIG. 18;

in fig. 20 shows a cross section of the fluid cartridge system and the passage of air through the fluid.

In FIG. 1a-1d show schematic illustrations of an aerosol generating system including a cartridge, in accordance with an embodiment of the invention. In FIG. 1a shows a schematic view of an aerosol generating device 10 and a separate cartridge 20 which together form an aerosol generating system. In this example, the aerosol generating system is an electrically controlled smoking system.

The cartridge 20 contains an aerosol-forming substrate and is configured to fit into a cavity 18 within the device. The cartridge 20 must be configured to be replaced by the user if the aerosol-forming substrate provided in the cartridge is depleted. In FIG. 1a shows the cartridge 20 just before being inserted into the device, with the arrow 1 shown in FIG. 1a indicates the insertion direction of the cartridge.

The aerosol generating device 10 is portable and has a size comparable to that of a traditional cigar or cigarette. The device 10 includes a main part 11 and a mouthpiece 12. The main part 11 includes a battery 14 such as a lithium iron phosphate battery, a control electronics 16 and a cavity 18. open position, as shown in Fig. 1 and closed position as shown in FIG. 1d. Mouthpiece 12 is positioned in an open position to allow insertion and removal of cartridges 20 and is positioned in a closed position when the system is to be used to generate an aerosol, as will be described. The mouthpiece includes a plurality of air inlets 13 and an outlet 15. In use, the user puffs from the side of the outlet to draw air through the air inlets 13 through the mouthpiece into the outlet 15 and subsequently into the user's mouth or lungs. Internal baffles 17 are provided to force air to flow through mouthpiece 12 past the cartridge, as will be described.

Cavity 18 is circular in cross-section and sized to receive housing 24 of cartridge 20. Electrical connectors 19 are provided on the sides of cavity 18 to provide electrical connection between control electronics 16 and battery 14 and corresponding electrical contacts on cartridge 20.

In FIG. 1b shows the system shown in FIG. 1a with the cartridge inserted into cavity 18 and cover 26 removed. In this position, the electrical connectors are opposite the electrical contacts on the cartridge, as will be described.

In FIG. 1c shows the system shown in FIG. 1b with the cover 26 completely removed and the mouthpiece 12 moved to the closed position.

In FIG. 1d shows the system shown in FIG. 1c with the mouthpiece 12 in the closed position. The mouthpiece 12 is held in the closed position by a locking mechanism, as schematically illustrated in FIG. 2. In FIG. 2 illustrates the main body 11 and the mouthpiece 12 connected by a hinge 21. The mouthpiece 12 includes an inwardly extending tooth 8. When the mouthpiece is in the closed position, the tooth 8 engages the latch 6 on the main body of the device. The latch 6 is biased by the bias spring 5 to engage the tooth 8. The button 4 is attached to the latch 6. The button 4 can be pressed by the user in opposition to the bias spring 5 to release the tooth 8 from the latch 6, allowing the mouthpiece to move to the open position. It will now be apparent to one of skill in the art that other suitable mechanisms may be used to hold the mouthpiece in the closed position, such as a snap connection or a magnetic closure.

The mouthpiece 12 in the closed position keeps the cartridge in electrical contact with the electrical connectors 19 so that a good electrical connection is maintained in use regardless of the orientation of the system. Mouthpiece 12 may include an annular elastomeric member that contacts the surface of the cartridge and is compressed between the mouthpiece housing rigid member and the cartridge when mouthpiece 12 is in the closed position. This ensures that a good electrical connection is maintained despite manufacturing tolerances.

Of course, alternative or additional mechanisms may be used to maintain a good electrical connection between cartridge and device. For example, the body 24 of the cartridge 20 may be provided with a thread or groove (not illustrated) that engages a corresponding groove or thread (not illustrated) formed in the wall of the cavity 18. A threaded connection between the cartridge and the device may be used to ensure proper rotational alignment, as well as holding the cartridge in the cavity and ensuring a good electrical connection. The threaded connection may extend for only half a turn or less of the cartridge, or may extend for several turns. Alternatively or in addition, the electrical connectors 19 may be offset to make contact with the contacts on the cartridge, as will be described with reference to FIG. 8.

In FIG. 3 shows an exploded view of cartridge 20. Cartridge 20 includes a generally circular cylindrical body 24 that is sized and shaped to fit into cavity 18. The body contains capillary material 22 that is impregnated with an aerosol-forming liquid substrate. In this example, the aerosol forming substrate contains 39% by weight of glycerol, 39% by weight of propylene glycol, 20% by weight of water and flavors, and 2% by weight of nicotine. The capillary material is a material that actively transfers fluid from one end to the other and can be made from any suitable material. In this example, the capillary material is formed from polyester.

The housing has an open end to which a heater assembly 30 is attached. The heater assembly 30 comprises a substrate 34 having an opening 35 formed therein, a pair of electrical contacts 32 attached to the substrate and separated from each other by a gap 33, and a plurality of electrically conductive filaments. 36 heater filling the hole and attached to the electrical contacts on opposite sides of the hole 35.

The heater assembly 30 is covered with a removable cover 26. The cover comprises a liquid impervious plastic sheet which is adhered to the heater assembly but which can be easily removed. A protrusion is provided on the side of the cover to enable the user to grasp the cover when removing it. It will now be apparent to one of skill in the art that although bonding has been described as a method of attaching an impermeable plastic sheet to a heater assembly, other methods known to those skilled in the art may be used, including thermal bonding or ultrasonic welding, when provided that the coating can be easily removed by the consumer.

In FIG. 4 is an exploded view of an alternative exemplary cartridge. The cartridge shown in Fig. 4 has the same size and shape as the cartridge shown in FIG. 3 and has the same housing and heater assembly. However, the capillary material inside the cartridge shown in FIG. 4 differs from the capillary material shown in FIG. 3. The cartridge shown in FIG. 4 comprises two separate capillary materials 27, 28. A disk of first capillary material 27 is provided for contact with heater element 36, 32 in use. Most of the second capillary material 28 is provided on the opposite side of the first capillary material 27 relative to the heater assembly. Both the first capillary material and the second capillary material hold a liquid substrate forming an aerosol. The first capillary material 27 that is in contact with the heater element has a higher thermal decomposition temperature (at least 160° C. or higher, such as about 250° C.) than the second capillary material 28. The first capillary material 27 effectively acts as a spacer separating the heater element 36, 32 from the second capillary material 28 so that the second capillary material is not exposed to temperatures in excess of its thermal decomposition temperature. The temperature difference in the first capillary material is such that the second capillary material is exposed to temperatures below its thermal decomposition temperature. The second capillary material 28 may be selected to have better capillary properties 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 example, the first capillary material is a heat resistant material, such as fiberglass or a material containing fiberglass, and the second capillary material is a polymer, such as a suitable capillary material. Exemplary suitable capillary materials include the capillary materials discussed herein and, in alternative embodiments, may include high density polyethylene (HDPE) or polyethylene terephthalate (PET).

In FIG. 5a is a bottom perspective view of the cartridge shown in FIG. 3. As shown in FIG. 5a, the heater assembly extends laterally and extends laterally beyond the housing 24 so that the heater assembly forms a flange around the top of the housing 24. The exposed portions of the electrical contacts 32 face in the cartridge insertion direction so that when the cartridge is fully inserted into cavity 18, the exposed portions of the contacts 32 are in contact with the electrical connectors 19. A protrusion provided on the side of the cover 26 to enable the user to grasp the cover when removing it can be clearly seen. In FIG. 5a also illustrates a driver 25 formed on the base of the cartridge to ensure proper orientation of the cartridge in the cavity of the device. The driver 25 is part of an injection molded body 24 and is configured to fit into a corresponding slot (not illustrated) in the base of the cavity 18. After the driver 25 is seated in the slot in the cavity, the contacts 32 align with the connectors 19.

In FIG. 5b is a top perspective view of the cartridge shown in FIG. 3, with the coating removed. The heater filaments 36 are open at the opening 35 in the substrate 34 so that the vaporized aerosol forming substrate can exit into the airflow through the heater assembly.

Housing 24 is formed from a thermoplastic such as polypropylene. Heater assembly 30 is glued to housing 24 in this example. However, there are several possible ways to assemble and fill the cartridge.

The cartridge body may be formed by injection molding. Capillary materials 22, 27, 28 may be formed by cutting suitable lengths of capillary material from a long rod of capillary fibers. The heater assembly may be assembled using the process as described with reference to FIG. 11a, 11b and 11c. In one embodiment, the assembly of the cartridge is as follows: first, one or more capillary materials 22, 27, 28 are inserted into the body 24. Then a predetermined volume of aerosol-forming liquid substrate is introduced into the body 24 and absorbed by the capillary materials. The heater assembly 30 is then pushed towards the open end of the housing and attached to the housing 24 by gluing, welding, heat bonding, ultrasonic welding, or other methods that will now be apparent to those skilled in the art. The body temperature is preferably kept below 160° C. during any sealing operation to prevent unwanted removal of volatile compounds from the aerosol forming substrate. The capillary material, after being cut, may be of such a length that it extends outward of the open end of housing 24 until it is compressed by the heater assembly. This facilitates transport of the aerosol-forming substrate into the interstices of the heater element during use.

In another embodiment, instead of pressing the heater assembly 30 against the housing 24 and then sealing, the heater assembly and the open end of the housing may first be rapidly heated and then pressed together to bond the heater assembly 30 and housing 24.

It is also possible to combine heater assembly 30 and housing 24 prior to filling the housing with an aerosol-forming substrate and then introducing the aerosol-forming substrate into housing 24. In this case, the heater assembly may be attached to the cartridge using any of the methods described. The heater assembly or housing is then pierced using a cannula and the aerosol forming substrate is introduced into the capillary material 22, 27, 28. Any hole made by the cannula is then sealed by heat bonding or sealing tape.

In FIG. 6 shows an illustration of a first heater assembly 30 in accordance with the invention. The heater assembly contains a mesh formed from 304L stainless steel with a mesh size of approximately 400 US mesh (approximately 400 threads per inch). The filaments have a diameter of approximately 16 microns. The grid is connected to electrical contacts 32, which are separated from each other by a gap 33 and are formed from a copper foil having a thickness of approximately 30 µm. Electrical contacts 32 are provided on a polyimide substrate 34 having a thickness of approximately 120 microns. The threads forming the mesh form the gaps between the threads. The spaces in this example are approximately 37 µm wide, although larger or smaller spaces may be used. The use of a mesh with these approximate dimensions allows the formation of aerosol-forming substrate in the interstices of the meniscus and the aerosol-forming substrate being drawn into the mesh of the heater assembly by capillary action. Open grid area, i.e. the ratio of the area of the gaps to the total area of the grid, preferably ranges from 25 to 56%. The total resistance of the heater assembly is approximately 1 ohm. The mesh provides a significant portion of this resistance, so most of the heat is produced by the mesh. In this example, the grid has an electrical resistance that is more than 100 times the electrical resistance of the electrical contacts 32.

Substrate 34 is electrically insulating and in this example is formed from a polyimide sheet having a thickness of approximately 120 microns. The substrate has a round shape and a diameter of 8 mm. The grid has a rectangular shape and a side length of 5 mm and 2 mm. These dimensions make it possible to make a complete system similar in size and shape to a traditional cigarette or cigar. Another example of sizes that have been found to be effective are a 5 mm round substrate and a 1 mm × 4 mm rectangular mesh.

In FIG. 7 is an illustration of an alternative exemplary heater assembly in accordance with the invention. The heater assembly shown in Fig. 7 is similar to that shown in FIG. 6, but the mesh 36 has been replaced by an array of parallel electrically conductive filaments 37. The array of filaments 37 is formed from 304L stainless steel and has a diameter of approximately 16 microns. Substrate 34 and copper contact 32 are the same as described with reference to FIG. 6.

In FIG. 8 shows an illustration of yet another alternative heater assembly in accordance with the invention. The heater assembly shown in Fig. 8 is similar to that shown in FIG. 7, but in the heater assembly shown in FIG. 8, strands 37 are bonded directly to substrate 34 and contacts 32 are then bonded to strands. As before, the contacts 32 are separated from each other by an insulating gap 33 and are formed from a copper foil having a thickness of approximately 30 µm. A similar arrangement of substrate filaments and contacts can be used for a grid-type heater as shown in FIG. 6. The presence of contacts as an edge layer can be beneficial to ensure reliable electrical contact with the power source.

In FIG. 9 shows an illustration of an alternative heater assembly in accordance with the invention. The heater assembly shown in Fig. 9 comprises a plurality of heater filaments 38 which, together with the electrical contacts 39, form one unit. Both the filaments and electrical contacts are formed from stainless steel foil which is etched to form filaments 38. The contacts 39 are separated by a gap 33 except when connected by filaments 38. The stainless steel foil is provided on a polyimide substrate 34. The filaments 38 again provide a significant portion of this resistance, so that most of the heat is produced by the filaments. In this example, the filaments 38 have an electrical resistance that is more than 100 times the electrical resistance of the electrical contacts 39.

In the cartridge shown in Fig. 3, 4, and 5, pins 32 and filaments 36, 38 are positioned between substrate layer 34 and body 24. However, it is possible to mount the heater assembly on the cartridge body in a different manner so that the polyimide substrate is located directly adjacent to body 24. On fig. 10 illustrates this type of arrangement. In FIG. 10 shows a heater assembly comprising a stainless steel mesh 56 attached to copper foil contacts 52. Copper contacts 52 are attached to the polyimide substrate 54. An opening 55 is formed in the polyimide substrate 54. The polyimide substrate is welded to the cartridge body 24. The capillary material 22, impregnated with the aerosolizing substrate, fills the housing and extends through the opening to contact the mesh 55. As shown, the cartridge fits into the main body 11 of the device and is held between the electrical connectors 59 and the mouthpiece 12. In this embodiment, for electrical connection electrical connectors 59 with pins 52, connectors 59 are configured to pierce the polyimide substrate 54 as shown. The electrical connectors are tapered and come into contact with the heater assembly under the action of springs 57. The polyimide substrate may be pre-cut to provide good electrical contact, or may be provided with holes so that piercing the substrate may not be necessary. The springs 57 also ensure that good electrical contact is maintained between contacts 52 and connectors 59 regardless of the orientation of the system with respect to gravity.

One means of ensuring the correct orientation of the cartridge 20 in the cavity 18 of the device has been described with reference to FIG. 5a and 5b. The driver portion 25 may be formed as part of a molded cartridge body 24 to ensure correct orientation. However, it is obvious that other ways to ensure the correct orientation of the cartridge are possible. In particular, if the housing is made by injection molding, there are practically unlimited possibilities with regard to the shape of the cartridge. After choosing the desired internal volume of the cartridge, the shape of the cartridge can be made in such a way as to fit any cavity. In FIG. 11a shows a basic view of one possible cartridge body 70 that allows the cartridge to be oriented in two possible orientations. The cartridge body 70 includes two symmetrically spaced grooves 72. The grooves may extend partially or completely up the side of the body 70. Appropriate ribs (not illustrated) may be formed on the walls of the device cavity such that the cartridge can be received in the cavity in only two possible orientations. In the embodiment shown in FIG. 11a, it is possible to have only one fin in the cavity, so that one of the grooves 72 is not filled with a fin and can be used as an airflow conduit within the device. Of course, it is possible to limit the cartridge to one orientation within the cavity by providing only one groove in the body. This is illustrated in FIG. 11b, which shows the cartridge body 74 with one groove 76.

While cartridges with bodies having a substantially circular cross section are available in the described embodiments, it is of course possible to form cartridge bodies of other shapes, such as a rectangular cross section or a triangular cross section. These body shapes will provide the necessary orientation within the appropriately shaped cavity to provide an electrical connection between the device and the cartridge.

The capillary material 22 is advantageously oriented in the housing 24 so as to transfer fluid to the heater assembly 30. Once the cartridge is assembled, the heater filaments 36, 37, 38 may be in contact with the capillary material 22 and hence the aerosol forming substrate may be transferred directly. to grid heater. In FIG. 12a is a detailed view of the assembled heater filaments 36 showing a meniscus 40 of aerosol forming liquid substrate between the heater filaments 36 . As shown, the aerosol generating substrate is in contact with most of the surface of each filament so that most of the heat generated by the heater assembly continues directly into the aerosol generating substrate. In contrast, in traditional wick and spool heaters, only a small portion of the heater wire is in contact with the aerosol-generating substrate. In FIG. 12b shows a detailed view similar to that shown in FIG. 12a, which shows an example of capillary material 27 that extends into the interstices between threads 36. Capillary material 27 is the first capillary material shown in FIG. 4. As shown, transport of liquid to the filaments can be achieved by providing a capillary material containing thin strands of fibers that extend into the spaces between the filaments 36.

In use, the heater assembly works by resistive heating. The current continues through the filaments 36, 37, 38 under the control of the control electronics 16 to heat the filaments to the required temperature range. The grid or matrix of filaments has a significantly higher electrical resistance than the electrical contacts 32 and electrical connectors 19 so that high temperatures are localized on the filaments. The system may be configured to generate heat by providing electrical current to the heater assembly in response to a puff by the user, or may be configured to continuously generate heat while the device is in an "on" state. Different filament materials may be suitable for different systems. For example, in a continuously heated system, graphite filaments are suitable because they have a relatively low specific heat and are compatible with low current heating. In a puff-activated system in which heat is generated by short flashes using high current pulses, stainless steel filaments having a high specific heat capacity may be more suitable.

In a puff-activated system, the device may include a puff sensor configured to detect that the user is drawing air through the mouthpiece. A puff sensor (not illustrated) is coupled to control electronics 16 and control electronics 16 is configured to energize heater assembly 30 only when it is determined that the user is puffing from the device. Any suitable air flow sensor can be used as a puff sensor, such as a microphone.

In an exemplary embodiment, changes in the resistance of one or more filaments 36, 38, or the heater element as a whole, can be used to detect a change in the temperature of the heater element. This can be used to adjust the power supplied to the heater element to ensure that it stays within the desired temperature range. Rapid changes in temperature may also be used as indicators to detect changes in airflow downstream of the heater element as a result of user puffing from the system. One or more filaments may be dedicated temperature sensors and may be formed from a material having a temperature coefficient of resistance suitable for the purpose, such as an iron/aluminum alloy, Ni-Cr, platinum, tungsten, or alloy wire.

The flow of air through the mouthpiece when using the system is illustrated in FIG. 1d. The mouthpiece includes internal baffles 17 which are integrally molded with the outer walls of the mouthpiece and allow air to flow through the heater assembly 30 to the cartridge where the aerosol-forming substrate evaporates while drawing air from the inlets 13 into the outlet 15. as air passes through the heater assembly, the vaporized substrate is drawn into the air stream and cooled to form an aerosol before exiting the outlet 15. Accordingly, in use, the aerosol generating substrate continues through the heater assembly as it evaporates by passing through the interstices between the filaments 36, 37, 38.

There are a number of possibilities regarding the manufacture and materials of the heater assembly. In FIG. 13a is a schematic illustration of a first method for manufacturing a heater assembly. A series of holes 82 is provided in the roll of polyimide film 80. The holes 82 may be formed by punching. Strips of copper foil 84 are applied to the polyimide film 80 between the holes. The stainless steel mesh strips 86 are then applied to the polyimide film 80 over the copper foil 84 and holes 82 in a direction perpendicular to the copper foil strips. Individual heater assemblies 30 can then be cut or stamped around each hole 82. Each heater assembly 30 includes a piece of copper foil on opposite sides of the hole to form electrical contacts, and a strip of stainless steel mesh fills the hole from one piece of copper to the other, as shown. in fig. 6.

In FIG. 13b illustrates another possible manufacturing process. In the process shown in FIG. 13b, polyimide film 80 of the type used in the process shown in FIG. 13a is covered with stainless steel foil 90. The polyimide film 80 has a number of holes 82 formed therein, but these holes are covered with a stainless steel foil 90. The foil 90 is then etched to form filaments 38 filling the holes 82 and separating contact pieces on opposite sides of the holes. Individual heater assemblies 92 may then be cut or stamped around each opening 82. This provides a heater assembly of the type shown in FIG. 9.

In FIG. 13c illustrates a further alternative process. In the process shown in FIG. 13c, the graphite-based material 100 is first prepared. The graphite-based material 100 includes strips of electrically resistive fibers suitable for use as heater filaments alongside strips of relatively non-conductive fibers. These strips of fibers are woven together with strips of relatively electrically conductive fibers that run perpendicular to the resistive and non-conductive fibers. This material 100 is then bonded to a polyimide film layer 80 of the type described with reference to FIG. 13a and 13b having a series of holes 82. Individual heater assemblies 102 can then be cut or stamped around each hole. Each heater assembly 102 includes a portion of a strip of conductive fibers on opposite sides of the opening and a strip of electrically resistive fibers filling the opening.

The cartridge design shown in Fig. 5a and 5b has several advantages. However, alternative cartridge designs using a similar type of heater assembly are possible. In FIG. 14 illustrates an alternative cartridge design that is suitable for various air flow patterns through the system. In the embodiment shown in FIG. 14, cartridge 108 is insertable into the device in the direction indicated by arrow 110. Cartridge 108 includes a housing 112 that is shaped like half a cylinder and one side of which is open. Heater assembly 114 is positioned on the exposed side and is glued or welded to housing 112. Heater assembly 114 includes an electrically insulating substrate 116, such as polyimide, having an opening formed therein. A heater element containing a stainless steel mesh 118 and a pair of contact strips 120 is connected to an electrically insulating substrate 116 and fills the hole. The contact strips 120 wrap around the housing 112 to form pads on the curved surface of the housing. The electrical contact pads are configured to contact corresponding contacts (not illustrated) in the aerosol generating device. Housing 112 is filled with capillary material (not visible in FIG. 14) impregnated with an aerosol forming substrate as described with reference to the embodiment shown in FIG. 1a-1d.

The cartridge shown in Fig. 14 is configured to flow air through the heater assembly 114 in the opposite direction of arrow 110. Air is drawn into the system through an air inlet provided in the main portion of the device and is drawn 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 can be directed, for example, in a direction parallel along the mesh 118 by an appropriate arrangement of the air inlets.

Alternative embodiments of cartridge 108 are illustrated in FIG. 15a and 15b. In FIG. 15a further shows contact strips 120 spaced apart and extending along the length of the outer surface having the mesh 118. FIG. 15b further shows contacts 120 having an approximately L-shape. Both cartridge designs illustrated in FIG. 15a and 15b can be used to provide even larger contact areas to further provide easy contact with the contacts 19 if needed. Strips 120, as illustrated in FIG. 15a may also be slidable over contact 19, which is in a rail configuration (not illustrated) to receive strips 120 for additional cartridge placement. Such a rail configuration can advantageously provide periodic cleaning of the contacts 19 since the insertion and removal of the cartridge will have a cleaning effect based on the friction of the contact sliding in and out along the rails.

In FIG. 16 illustrates yet another embodiment of an aerosol generating system including a liquid-permeable electrical heater assembly. In FIG. 16 illustrates a system in which a heater assembly 30 is provided at the end of the cartridge 20 that is opposite the mouthpiece 12. The airflow enters the air inlet 1601 and continues past the heater assembly and through the air outlet 1603 along the flow path 1605. Electrical contacts can be located in any convenient place. This configuration is advantageous because it provides shorter electrical connections within the system.

Other cartridge designs incorporating a heater assembly in accordance with the present invention may now be provided by one of skill in the art. For example, the cartridge may include a mouthpiece, may include more than one heater assembly, and may be of any desired shape. In addition, the heater assembly according to the invention can be used in other types of systems than those already described, such as humidifiers, air fresheners and other aerosol generating systems.

The exemplary embodiments described above are provided for illustration and not limitation. In view of the above exemplary embodiments, other embodiments corresponding to the above exemplary embodiments will now be apparent to a person skilled in the art.

In FIG. 17 illustrates a cross-sectional view of the cartridge system, with the flow path comprising airflow directed through the cartridge. A liquid-permeable heater, such as a mesh heater 30, includes electrically conductive heater filaments 36 filling an opening in the housing 400. To seal the upper portion of the housing 400, a sealing layer 48, such as a polymer layer, is provided between the upper edge of the housing 400 and the heater 30. In addition, , a sealing disc 47, such as a resin disc, is provided on the upper side of the heater 30. By using the sealing disc 47, air flow through the heater can be controlled, in particular, air flow restrictions can be provided. The sealing disk may also be located on the underside of the heater 30.

The cartridge body 400 includes a capillary material containing liquid, such as a high retention or high release material (HRM) 41, serving as a reservoir for the liquid and directing the liquid towards the heater 30 to be vaporized on the heater. Another capillary material, a capillary disk 44, such as a fibrous disk, is located between the HRM 41 and the heater 30. The material of the capillary disk 44 may be more heat resistant than the HRM 41 due to its proximity to the heater 30. The capillary disk is kept wet with using an aerosol generating liquid HRM to safely provide a liquid to vaporize when the heater is activated.

The body 400 is provided with an air-permeable bottom 45. The air-permeable bottom is provided with an inlet 450 for air flow. The airflow inlet 450 allows air to flow through the bottom 45 into the housing in one and only that direction. Neither air nor liquid can exit the housing through the breathable bottom 45. The breathable bottom 45 may, for example, comprise a semi-permeable membrane as an airflow inlet 450, or may be a bottom cover containing one or more one-way valves, as will be shown. Further.

If a slight decrease in pressure predominates on the heater side, as happens during puffing, air can continue through the air inlet 450 to flow into the cartridge. The air stream 200 will continue through the HRM 41 and through the heater 30. The aerosol-containing air stream 200 will then flow to the downstream end of the aerosol generating device, preferably into a centrally located channel in the mouthpiece.

The sidewalls of the housing 400 may also be provided with side air permeable sections 46 to allow subsequent airflows into the housing. The side air-permeable sections 46 may be provided as airflow inlets 450 in the air-permeable bottom 45.

In FIG. 18, the layout and functions of the cartridge system are basically the same as those shown in FIG. 10. However, a central opening 412 is provided in the HRM 41. Air entering the airflow inlet 450 in the case bottom 45 continues through the central opening 412. The airflow continues near the HRM in the cartridge. By using the optional side air permeable sections 46 in the side wall of the housing 400, lateral airflow can be provided through the HRM 41.

In FIG. 19 is an exploded view of the cartridge system shown in FIG. 11. An annular tubular HRM 41 is provided in a housing 400. The bottom 45 of the housing is a disk containing a one-way valve 49 located in the center of the disk and aligned with a central opening 412 in the HRM 41. Such a one-way valve may, for example, be a commercially available valve such as , such as those used in medical devices or baby bottles.

In FIG. 20 shows a cross section of yet another embodiment of a cartridge system. For the same or similar elements, the same reference numbers are used. In this embodiment, the housing 400 is filled with an aerosol-forming liquid 411. The housing may be made of a metal material, a plastic material such as a polymer material, or glass. The valve 49 may be directly molded into the bottom 45 of the housing. The bottom 45 may also be provided with a cavity for an airtight valve assembly. Due to the fact that the flaps are preferably made of a flexible material, an impermeable assembly can be achieved using the bottom material.

In the above cartridge systems, as described with respect to FIG. 17-20, the cartridge body 400 may also be a separate cartridge container in addition to the cartridge body, as described, for example, with respect to FIG. 1. Specifically, the cartridge containing the liquid 411 is a prefabricated product that can be inserted into a cartridge body provided in the aerosol generating system to accommodate the prefabricated cartridge.

Claims (23)

1. An aerosol generating system comprising a liquid storage portion comprising a rigid housing holding a liquid substrate forming an aerosol, wherein the housing has an opening, and a liquid-permeable heater assembly comprising a plurality of electrically conductive filaments forming a grid while being permeable for liquid, the heater assembly is made flat, attached to the rigid body and extends across the opening of the rigid body. 2. An aerosol generating system according to claim 1, characterized in that the area of the liquid-permeable heater assembly is less than 25 mm ² . 3. An aerosol generating system according to any one of paragraphs. 1 or 2, characterized in that it comprises a main unit and a cartridge that is removably connected to the main unit, wherein the liquid storage part and the heater assembly are provided in the cartridge, and the main unit contains a power source. 4. An aerosol generating system according to any one of paragraphs. 1-3, characterized in that the plurality of electrically conductive threads includes a plurality of electrically conductive threads arranged parallel to each other. 5. An aerosol generating system according to any one of paragraphs. 1-4, characterized in that the body of the liquid storage part contains a capillary material. 6. An aerosol generating system according to claim 5, characterized in that the capillary material extends into the spaces between the threads. 7. An aerosol generating system according to claim 5 or 6, characterized in that the capillary material includes a first capillary material and a second capillary material, wherein the first capillary material is in contact with the heater assembly and the second capillary material is in contact with the first capillary material and separated from the heater assembly by the first capillary material, wherein the first capillary material has a higher thermal decomposition temperature than the second capillary material. 8. An aerosol generating system according to claim 7, characterized in that the thermal decomposition temperature of the first capillary material is at least 160°C and preferably at least 250°C. 9. An aerosol generating system according to any one of paragraphs. 1-8, characterized in that the heater assembly comprises at least one thread made of a first material and at least one thread made of a second material different from the first material. 10. An aerosol generating system according to any one of paragraphs. 1-9, characterized in that it further comprises an electrical circuit connected to the heater assembly and an electrical power source, wherein the electrical circuit is configured to control the electrical resistance of the heater assembly or one or more electrically conductive filaments of the heater assembly, and with the possibility controlling the application of power from an electrical power source to the heater assembly depending on the electrical resistance of the heater assembly or one or more electrically conductive filaments. 11. An aerosol generating system according to any one of paragraphs. 1-10, characterized in that the heater assembly comprises an electrically insulating substrate which provides support for the filaments. 12. An aerosol generating system according to any one of paragraphs. 1-11, characterized in that the heater assembly comprises an electrically conductive contact in contact with a plurality of electrically conductive filaments. 13. An aerosol generating system according to any one of paragraphs. 1-12, characterized in that it is an electrically controlled smoking system. 14. A cartridge for use in an electrically controlled aerosol generating system, comprising a liquid storage portion, comprising a rigid housing holding an aerosol-forming liquid substrate, the housing having an opening, and a liquid-permeable heater assembly comprising a plurality of electrically conductive filaments, forming a grid, wherein the liquid-permeable heater assembly is flat, attached to the housing, and extends across the opening of the housing. 15. The cartridge according to claim 14, characterized in that the plurality of filaments includes a plurality of filaments arranged parallel to each other. 16. The cartridge according to any one of paragraphs. 14 or 15, characterized in that the housing of the liquid storage part contains a capillary material. 17. Cartridge according to claim 16, characterized in that the capillary material extends into the spaces between the electrically conductive threads. 18. Cartridge according to any one of paragraphs. 16 or 17, characterized in that the capillary material includes a first capillary material and a second capillary material, wherein the first capillary material is in contact with the heater assembly and the second capillary material is in contact with the first capillary material and is separated from the heater assembly by the first capillary material. material, wherein the first capillary material has a higher thermal decomposition temperature than the second capillary material. 19. Cartridge according to any one of paragraphs. 14-18, characterized in that the heater assembly comprises at least one electrically conductive thread made of a first material and at least one electrically conductive thread made of a second material different from the first material. 20. The cartridge according to any one of paragraphs. 14-19, characterized in that the heater assembly comprises an electrically insulating substrate on which electrically conductive filaments are located, while the electrically conductive filaments extend across a hole formed in the substrate. 21. Cartridge according to any one of paragraphs. 14-20, characterized in that the heater assembly comprises an electrically conductive contact in contact with a plurality of electrically conductive filaments. 22. A cartridge according to claim 21, wherein the heater assembly extends in a lateral plane and the electrically conductive contact extends sideways outside the body of the liquid storage portion. 23. A method of manufacturing a cartridge for use in an electrically controlled aerosol generating system comprising providing a liquid storage portion comprising a rigid body having an opening, filling the liquid storage portion with an aerosol generating liquid substrate, and attaching a liquid permeable heater assembly comprising a plurality of electrically conductive mesh-forming filaments to the liquid storage part, wherein the liquid-permeable heater assembly is flat and extends across the body opening of the liquid storage part.

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