EP4694707A1

EP4694707A1 - An aerosol-generating system and a cartridge for an aerosol-generating system with liquid leakage mitigation

Info

Publication number: EP4694707A1
Application number: EP23723110.5A
Authority: EP
Inventors: Wanjiang Han; Ruilong HU; Baofeng Xie
Original assignee: Philip Morris Products SA
Current assignee: Philip Morris Products SA
Priority date: 2023-04-14
Filing date: 2023-04-14
Publication date: 2026-02-18
Also published as: CN121001592A; JP2026512729A; KR20250165682A; WO2024212219A1

Abstract

A cartridge for an aerosol-generating system, the cartridge comprising a housing, the housing defining a reservoir containing a liquid aerosol-forming substrate, a heater, the heater comprising a heating element and a porous body, the heating element positioned on a heating surface of the porous body, the porous body configured to convey the liquid aerosol-forming substrate to the heating element and a heater holder (130), the heater holder supporting the heater within the housing and comprising one or more first sealing ribs (118) on an outer surface that engage the housing to seal the reservoir and a plurality of channels (108) formed between the outer surface of the heater holder and the housing on an opposite side of the first sealing ribs to the reservoir.

Description

AN AEROSOL-GENERATING SYSTEM AND A CARTRIDGE FOR AN AEROSOL-GENERATING SYSTEM WITH LIQUID LEAKAGE MITIGATION

The present disclosure relates to a cartridge for an aerosol-generating system and an aerosol-generating system. In particular, the present disclosure relates to a cartridge for an aerosol-generating system and an aerosol-generating system that holds a liquid aerosol-forming substrate and that includes an arrangement that mitigates liquid leakage.
Aerosol-generating systems that vaporise a liquid aerosol-forming substrate to generate an aerosol for user inhalation are known in the art. The aerosol-generating systems typically comprise a heater for heating the liquid aerosol-forming substrate. The liquid aerosol-forming substrate is heated and vaporised by the heater to form a vapour. The vapour cools and condenses to form an aerosol, and this aerosol is then inhaled by a user. Such aerosol-generating systems are typically handheld and comprise a power supply for supplying power to the heater and a reservoir for holding a supply of the liquid aerosol-forming substrate. Some aerosol-generating systems comprise an aerosol-generating device and a cartridge that is configured to be used with the device. When the aerosol-generating system comprises an aerosol-generating device and a cartridge, the reservoir of liquid aerosol-forming substrate forms part of the cartridge.
The liquid aerosol-forming substrate must be allowed to pass from the reservoir to the heater and then from the heater, in vapour form, to an airflow channel within the system or cartridge. The heater is typically held within the system or cartridge in a heater holder structure. The heater holder structure may be used to seal the liquid reservoir and to allow liquid to pass from the reservoir to the heater. This may require additional sealing components to ensure that liquid cannot leak between the heater holder structure and the housing of the liquid reservoir. In particular, manufacturing tolerances mean that a small gap may be present between the heater holder structure and the housing even if it is designed to provide an interference fit. Further, when the pressure within the liquid reservoir changes or when the atmospheric pressure changes, liquid may be drawn out of the housing through any gaps between the heater holder and the housing or may be drawn out of the porous body.
It would be desirable to provide an aerosol-generating system and a cartridge for an aerosol-generating system of this type which is simple and inexpensive to manufacture but which also prevents or mitigates liquid leaking from the system or cartridge before it has been vaporised.
In accordance with a first aspect of the disclosure, there is provided a cartridge for an aerosol-generating system. The cartridge may comprise:
a housing, the housing defining a reservoir containing a liquid aerosol-forming substrate. The cartridge may comprise a heater. The heater may comprise a heating element and a porous body. The heating element may be positioned on a heating surface of the porous body. The porous body may be configured to convey the liquid aerosol-forming substrate to the heating element. The cartridge may also comprise a heater holder. The heater holder may support the heater within the housing. The heater holder may optionally comprise one or more first sealing ribs on an outer surface that engage the housing to seal the reservoir. The cartridge may comprise a plurality of channels formed between the outer surface of the heater holder and the housing. The plurality of channels may be on an opposite side of the first sealing ribs to the reservoir.
The plurality of channels formed between the outer surface of the heater holder and the housing advantageously hold liquid that has passed the one or more first sealing ribs. The plurality of channels formed between the outer surface of the heater holder and the housing advantageously trap liquid that has passed the one or more first sealing ribs. The plurality of channels formed between the outer surface of the heater holder and the housing may advantageously hold or trap liquid that has escaped from the porous body. In this way, the possibility of liquid undesirably leaking from the cartridge and reaching the user or the outside environment is reduced or mitigated.
The plurality of channels may be formed by one or more protrusions formed on the outer surface of the heater holder. The plurality of channels may be formed by one or more protrusions formed on the inner surface of the housing. The plurality of channels may be formed by one or more protrusions formed on the outer surface of the heater holder and one or more protrusions formed on the inner surface of the housing. Advantageously, no additional components are required to form the plurality of channels.
Advantageously, each of the plurality of channels have dimensions that allow a meniscus of the liquid aerosol-forming substrate to be formed within the channel. Each of the plurality of channels may have a width of between 0.5mm and 2mm, and more preferably between 0.5mm and 1 mm. Each of the plurality of channels may have a depth of between 0.5mm and 2mm, and more preferably between 0.5mm and 1 mm. Advantageously, the liquid aerosol-forming substrate adheres to one or walls of the plurality of channels to reduce the tendency of the liquid aerosol-forming substrate to flow through the plurality of channels. The material of the one or more walls may be chosen for its adhesive properties.
The plurality of channels may be serpentine channels. The plurality of channels may be labyrinthine channels. For a given available surface areas for the channels, serpentine or labyrinthine channels provide a longer path length within the channels than straight or aligned channels. By providing a longer path length within the channels, a large volume of liquid can be held in the channels and so a greater volume of liquid leakage from the reservoir or porous body can be mitigated.
Advantageously, the plurality of channels are interconnected channels. In a given available surface area, a plurality of interconnected channels can provide a greater volume for holding liquid than unconnected channels. A plurality of interconnected channels may also provide plural potential entry points for liquid into the interconnected channels. However it possible to provide two or more separate channels structures that are not interconnected.
The plurality of channels may be arranged in a plurality of different patterns or layouts. In one embodiment, the plurality of channels comprises three or more transverse channels and a plurality of longitudinal channels, each of the transverse channels connected to an adjacent transverse channel by one or more longitudinal channels, and wherein each longitudinal channel connects only two transverse channels. The transverse channels may extend in a transverse direction that is perpendicular to the longitudinal direction. This arrangement provides a plurality of interconnected serpentine channels.
The plurality of channels may comprise a first transverse channel, a second transverse channel and a third transverse channel, wherein second transverse channel is positioned between the first transverse channel and the third transverse channel, and wherein each longitudinal channel connecting the first transverse channel with the second transverse channel is offset in the transverse direction from each longitudinal channel connecting the second transverse channel with the third transverse channel. This arrangement provides a plurality of interconnected serpentine channels.
It is not essential that the liquid channels are aligned with the transverse and longitudinal directions. Some or all of the channels can be arranged to extend diagonally or along more complex, curved paths.
The heater holder may be configured to fit within, or partially within, the housing. The one or more first sealing ribs may engage an inner surface of the housing. The one or more first sealing ribs may extend around an outer circumference of the heater holder. The one or more first sealing ribs may engage the inner surface of the housing around an inner circumference of the housing. The plurality of channels may be formed between an inner circumferential surface of the housing and an outer circumferential surface of the heater holder.
One or more of the transverse channels may advantageously extend around an outer circumference of the heater holder. However, the channels may extend in any direction across the outer surface of the heater holder.
The heater holder may be configured so that, during assembly of the cartridge, the heater holder is pushed into the housing in a longitudinal direction. The longitudinal direction may be perpendicular to the transverse direction.
The cartridge may be configured to engage with a power supply unit. The power supply unit may comprise a power supply, such a battery. The power supply unit may comprise control circuitry. The cartridge may be configured to engage with a power supply unit in a longitudinal direction. The cartridge may have a connection end, for connecting with a power supply unit and a mouthpiece end opposite to the connection end. The connection end and the mouthpiece end may be separated along a longitudinal axis.
The heater holder may comprise one or more second sealing ribs on an opposite side of the channels to the first sealing ribs, the second sealing ribs engaging the housing. The one or more second sealing ribs may engage an inner surface of the housing. The one or more second sealing ribs may extend around an outer circumference of the heater holder. The one or more second sealing ribs may engage the inner surface of the housing around an inner circumference of the housing.
Liquid that has leaked past the one or more first sealing ribs or out of the porous body and into the plurality of channels, may be further retained by the one or more second sealing ribs.
The heater holder may comprise one or more liquid passages extending from the reservoir to the porous body. This allows liquid from the reservoir to enter the porous body from where it can be vaporised by the heating element.
The heater holder may comprise an airflow channel extending from the heating surface of the porous body to an air outlet. The air outlet may be positioned towards a mouthpiece end of the cartridge. The airflow channel may extend in a longitudinal direction. The airflow channel may be within or between the one or more liquid passages. The airflow channel may extend around the porous body.
The heater holder may comprise an elastomeric material. The heater holder may be formed from an elastomeric material. The heater holder may be formed entirely from an elastomeric material. Preferably, the heater holder comprises a thermoplastic elastomer having a Shore A hardness of between 60 and 80.
Preferably, the material of the heater holder has a Shore A hardness from 60 to 80. More preferably, the material of the heater holder has a Shore A hardness from 65 to 75. In particularly preferred embodiments, the material of the heater holder has a Shore A hardness of 70.
As used herein, the term “Shore A hardness” is used to describe the durometer hardness of a rubber-like material and is assessed in accordance with ASTM D2240 (2015) . The test effectively measures the penetration of a specified indentor into a specimen of the material under specified conditions of force and time. To this purpose, the specimen is placed on a hard flat surface. The indentor for the instrument is then pressed into the specimen making sure that it is parallel to the surface. The hardness is read within one second of firm contact with the specimen. The test specimens are generally 6.4 millimetres thick. It is possible to pile several specimens to achieve a thickness of 6.4 millimetres, but use of one specimen is preferred.
The heater holder may be formed from two or more materials. The two or more materials may be co-moulded to form the heater holder. For example, the first and second sealing ribs can be formed from a softer material than a main body of the heater holder. The one or more protrusions on the heater holder may be part of the main body of the heater holder.
The porous body may be a porous ceramic body. The porous body may comprise porous ceramic body or a porous glass body. In other words, the porous body may be a body comprising a porous ceramic, the porous ceramic having a plurality of pores, wherein at least some of the plurality of pores are interconnected. The porous body may be a body comprising a porous glass, the porous glass having a plurality of pores, wherein at least some of the plurality of pores are interconnected.
The heating element may be an electrical heating element. For example, the heating element may be an electrically resistive heating element. The heating element may be made from any suitable electrically conductive material. 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 of a ceramic material and a metallic material. In a preferred example, the electrical heating element may comprise one of more of NiCr and TiZr.
The heating element may have any suitable shape or form. Examples of suitable shapes and forms of the heating element include but are not limited to a band, a strip, a filament, a wire, a mesh, a spiral coil, fibres or a fabric.
The heating element may be located on and bonded to the heating surface of the porous body.
The heating element may be a metallic heating element, such as a metallic heating track.
The metallic track may comprise Ag-Pd alloy or Fe-Si alloy.
The heater may be arranged so that the heating surface faces a mouthpiece end of the cartridge. Alternatively, the heater may be arranged so that the heating surface faces a connection end of the cartridge. The heater may comprise more than one heating surface. The heater may comprise more than one heating element.
Advantageously, the heater holder is configured to expose the heating surface to the airflow channel. This allows vapour generated by the heater to be entrained in an airflow, in which it can condense to form an aerosol.
The heater may comprise electrical contacts at opposite ends of the heater element. Advantageously, the heater holder is configured to expose the electrical contacts. This allows connection of the electrical contacts to a power supply.
Advantageously, the housing is formed from a housing material. The cartridge housing may be formed from a durable material. The housing may be formed from a liquid impermeable material. Preferably, the housing material has a Shore A hardness greater that the Shore A hardness of the heater holder. More preferably, the housing material has a Shore A hardness greater than 80. In particularly preferred embodiments, the material of the heater holder has a Shore A hardness of 85. The housing may be formed from a mouldable plastics material, such as polypropylene (PP) or polyethylene terephthalate (PET) . The housing material may be polyether ether ketone (PEEK) or Tritan.
In another aspect, the present disclosure also provides an aerosol-generating system, comprising:
a cartridge as described in the first aspect; and
a power supply unit configured to provide power to the heating element.
The power supply unit may comprise a power supply, such a battery. The power supply unit may comprise control circuitry. The control circuitry may regulate the supply of electrical energy to the heater.
The cartridge may be configured to engage with a power supply unit in a longitudinal direction. The cartridge may have a connection end, for connecting with a power supply unit and a mouthpiece end opposite to the connection end.
In further aspect, the present disclosure provides an aerosol-generating system, comprising a housing, the housing defining a reservoir containing a liquid aerosol-forming substrate. The aerosol-generating system may comprise a heater. The heater may comprise a heating element and a porous body. The heating element may be positioned on a heating surface of the porous body. The porous body may be configured to convey the liquid aerosol-forming substrate to the heating element. The system may comprise a heater holder, the heater holder supporting the heater within the housing. The heater holder may comprise one or more first sealing ribs on an outer surface that engage the housing to seal the reservoir. The aerosol-generating system may comprise a plurality of channels formed between the outer surface of the heater holder and the housing. The plurality of channels may be on an opposite side of the first sealing ribs to the reservoir.
The aerosol-generating system may be a one-piece system that is disposed of once the liquid aerosol-forming substrate is exhausted.
In all aspects of the disclosure, the aerosol-generating system may be a handheld aerosol-generating system. The aerosol-generating system may be a handheld aerosol-generating system configured to allow a user to suck on a mouthpiece to draw an aerosol through a first air outlet. The aerosol-generating system may have a size comparable to a conventional cigar or cigarette. The aerosol-generating system may have a total length between about 25 mm and about 150 mm. The aerosol-generating system may have an external diameter between about 5 mm and about 30mm.
In all aspects of the disclosure, the power supply may be a DC power supply. The power supply may be a battery. The battery may be a Lithium based battery, for example a Lithium-Cobalt, a Lithium-Iron-Phosphate, a Lithium Titanate or a Lithium-Polymer battery. The battery may be a Nickel metal hydride battery or a Nickel cadmium battery. The power supply may be another form of charge storage device such as a capacitor.
As used herein, the term “aerosol” is used to describe a dispersion of solid particles, liquid droplets, or a combination of solid particles and liquid droplets, in a gas. The aerosol may be visible or invisible. The aerosol may include vapours of substances that are ordinarily liquid or solid at room temperature as well as solid particles, liquid droplets, or a combination of solid particles and liquid droplets.
As used herein, the term “liquid aerosol-forming substrate” is used to describe to a liquid substrate capable of releasing volatile compounds that may form an aerosol. Such volatile compounds may be released by heating the liquid aerosol-forming substrate. The liquid aerosol-forming substrate may comprise one or more aerosol-formers. An aerosol-former is any suitable known compound or mixture of compounds that, in use, facilitates formation of a dense and stable aerosol and that is substantially resistant to thermal degradation at the temperature of operation of the system. Examples of suitable aerosol formers include glycerine and propylene glycol. Suitable aerosol-formers are well known in the art and include, but are not limited to: polyhydric alcohols, such as triethylene glycol, 1, 3-butanediol and glycerine; esters of polyhydric alcohols, such as glycerol mono-, di-or triacetate; and aliphatic esters of mono-, di-or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. The liquid aerosol-forming substrate may comprise water, solvents, ethanol, plant extracts and natural or artificial flavours. The liquid aerosol-forming substrate may comprise nicotine and at least one aerosol former. The aerosol former may be glycerine or propylene glycol. The aerosol former may comprise both glycerine and propylene glycol. The liquid aerosol-forming substrate may have a nicotine concentration of between about 0.5%and about 10%, for example about 2%.
As used herein, an “aerosol-generating system” means a system that generates an aerosol from one or more liquid aerosol-forming substrates.
As used herein, the term “heating element” is used to describe a component that generates heat and transfers heat energy to the liquid aerosol-forming substrate. It will be appreciated that the heating element may be located directly on the porous body or indirectly on the porous body. It will be appreciated that the heating element may be integrally formed with the porous body.
As used herein, the term “porous body” is used to describe a component that has a plurality of pores, at least some of which are interconnected. The porous body is configured to contain liquid within the plurality of pores. The porous body of the heater assembly in accordance with the first aspect of the invention comprises a porous ceramic body or a porous glass body. The porous body may be a porous ceramic body or a porous glass body.
As used herein, the term “heating surface” refers to the surface of the porous body nearest to the heating element. The heating surface of the porous body may be in contact with the heating element.
The invention is defined in the claims. However, below there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.
EX1. A cartridge for an aerosol-generating system, the cartridge comprising:
a housing, the housing defining a reservoir containing a liquid aerosol-forming substrate;
a heater, the heater comprising a heating element and a porous body, the heating element positioned on a heating surface of the porous body, the porous body configured to convey the liquid aerosol-forming substrate to the heating element; and
a heater holder, the heater holder supporting the heater within the housing and comprising one or more first sealing ribs on an outer surface that engage the housing to seal the reservoir; and
a plurality of channels formed between the outer surface of the heater holder and the housing on an opposite side of the first sealing ribs to the reservoir.
EX2. A cartridge according to Example EX1, wherein the plurality of channels is formed by one or more protrusions formed on the outer surface of the heater holder.
EX3. A cartridge according to Example EX1, wherein the plurality of channels are be formed by one or more protrusions formed on the inner surface of the housing.
EX4. A cartridge according to Example EX1, wherein the plurality of channels are formed by one or more protrusions formed on the outer surface of the heater holder and one or more protrusions formed on the inner surface of the housing.
EX5. A cartridge according to any one of the preceding examples, wherein each of the plurality of channels have dimensions that allow a meniscus of the liquid aerosol-forming substrate to be formed within the channel.
EX6. A cartridge according to any one of the preceding examples, wherein the plurality of channels are serpentine channels or labyrinthine channels.
EX7. A cartridge according to any one of the preceding examples, wherein the plurality of channels are interconnected channels.
EX8. A cartridge according to any one of the preceding examples, wherein the plurality of channels comprise three or more transverse channels and a plurality of longitudinal channels, each of the transverse channels connected to an adjacent transverse channel by one or more longitudinal channels, and wherein each longitudinal channel connects only two transverse channels.
EX9. A cartridge according to any one of the preceding examples, wherein the plurality of channels comprise a first transverse channel, a second transverse channel and a third transverse channel, wherein second transverse channel is positioned between the first transverse channel and the third transverse channel, and wherein each longitudinal channel connecting the first transverse channel with the second transverse channel is offset in the transverse direction from each longitudinal channel connecting the second transverse channel with the third transverse channel.
EX10. A cartridge according to any one of the preceding examples, wherein the heater holder is configured to fit within, or partially within, the housing.
EX11. A cartridge according to any one of the preceding examples, wherein the one or more first sealing ribs engage an inner surface of the housing.
EX12. A cartridge according to any one of the preceding examples, wherein the one or more first sealing ribs extend around an outer circumference of the heater holder.
EX13. A cartridge according to any one of the preceding examples, wherein the one or more first sealing ribs engage the inner surface of the housing around an inner circumference of the housing.
EX14. A cartridge according to any one of the preceding examples, wherein the plurality of channels is formed between an inner circumferential surface of the housing and an outer circumferential surface of the heater holder.
EX15. A cartridge according to example EX8 or EX9, wherein one or more of the transverse channels extend around an outer circumference of the heater holder.
EX16. A cartridge according to any one of the preceding examples, wherein the heater holder is configured so that, during assembly of the cartridge, the heater holder is pushed into the housing in a longitudinal direction.
EX17. A cartridge according to any one of the preceding examples, wherein the cartridge is configured to engage with a power supply unit.
EX18. A cartridge according to any one of the preceding examples, wherein the power supply unit comprises a power supply, such a battery, and control circuitry.
EX19. A cartridge according to any one of the preceding examples, wherein the heater holder comprises one or more second sealing ribs on an opposite side of the channels to the first sealing ribs, the second sealing ribs engaging the housing.
EX20. A cartridge according to example EX19, wherein the one or more second sealing ribs engage an inner surface of the housing.
EX21. A cartridge according to example EX19 or EX20, wherein the one or more second sealing ribs extend around an outer circumference of the heater holder.
EX22. A cartridge according to example EX19, EX20 or EX21, wherein the one or more second sealing ribs engage the inner surface of the housing around an inner circumference of the housing.
EX23. A cartridge according to any one of the preceding examples, wherein the heater holder comprises one or more liquid passages extending from the reservoir to the porous body.
EX24. A cartridge according to any one of the preceding examples, wherein the heater holder comprises an airflow channel extending from the heating surface of the porous body to an air outlet.
EX25. A cartridge according to any one of the preceding examples, wherein the heater holder comprises an elastomeric material.
EX26. A cartridge according to any one of the preceding examples, wherein the heater holder comprises a thermoplastic elastomer having a Shore A hardness of between 60 and 80.
EX27. A cartridge according to any one of the preceding examples, wherein the material of the heater holder has a Shore A hardness from 60 to 80, preferably from 65 to 75, and more preferably 70.
EX28. A cartridge according to any one of the preceding examples, wherein the heater holder is configured to expose the heating surface to the airflow channel.
EX29. A cartridge according to any one of the preceding examples, wherein the heater comprises electrical contacts at opposite ends of the heater element, and wherein the heater holder is configured to expose the electrical contacts.
EX30. A cartridge according to any one of the preceding examples, wherein the housing is formed from a housing material having a Shore A hardness greater that the Shore A hardness of the heater holder.
EX31. A cartridge according to example EX30, wherein the housing material has a Shore A hardness greater than 80.
EX32. An aerosol-generating system, comprising:
a cartridge according to any one of example EX1 to EX31; and
a power supply unit configured to provide power to the heating element.
EX33. An aerosol-generating system, comprising:
a housing, the housing defining a reservoir containing a liquid aerosol-forming substrate;
a heater, the heater comprising a heating element and a porous body, the heating element positioned on a heating surface of the porous body, the porous body configured to convey the liquid aerosol-forming substrate to the heating element; and
a heater holder, the heater holder supporting the heater within the housing and comprising one or more first sealing ribs on an outer surface that engage the housing to seal the reservoir; and
a plurality of channels formed between the outer surface of the heater holder and the housing on an opposite side of the first sealing ribs to the reservoir.
EX34. The aerosol-generating system may be a one-piece system that is disposed of once the liquid aerosol-forming substrate is exhausted.
Examples will now be further described with reference to the accompanying Figures, wherein:
Figure 1A shows a schematic cross-sectional view of an aerosol-generating system according to the present disclosure;
Figure 1 B shows a schematic cross-sectional view of the aerosol-generating system of Figure 1A in a use configuration;
Figure 2 shows a schematic view of a heater holder according to the present disclosure;
Figure 3 shows a perspective view of a heater assembly according to the present disclosure;
Figure 4A shows a perspective view of the porous body and heating element;
Figure 4B shows an alternative perspective view of the porous body of Figure 5A;
Figure 5 shows a schematic view of an alternative embodiment according to the present disclosure;
Figure 6A shows a first pattern of protrusions that could be used in embodiments of the disclosure; and
Figure 6B shows a second pattern of protrusions that could be used in embodiments of the disclosure.
Figure 1A shows a schematic cross-sectional view of a disassembled aerosol-generating system 100 according to the present disclosure. The aerosol-generating system 100 comprises a cartridge 140 and a power supply unit 150.
The cartridge comprises a housing 110 and a heater assembly 120. The housing 110 and heater assembly 120 assembled together form the cartridge 140. The cartridge 140 is reversibly couplable to the power supply unit 150 to form the aerosol-generating system 100. The cartridge 140 coupled to the power supply unit 150 provides the use configuration of the aerosol-generating system, which is shown in Figure 1 B. Alternatively, the system 100 may be provided as a singular aerosol-generating device comprising the housing 110, heater assembly 120, and power supply unit 150 assembled together rather than as a separable cartridge and power supply unit.
The housing 110 comprises an outer wall formed from a polymer. An example polymer may be Tritan or polyether ether ketone (PEEK) . The outer wall of the housing 110 defines a liquid reservoir 116 for containing liquid aerosol-forming substrate.
The housing 110 further comprises an airflow passage 112 that passes within the reservoir 116. The airflow passage 112 extends from a proximal end of the housing 110 towards a distal end of the housing 110. The wall defining the airflow passage 112 is also formed from a polymer or a copolymer, for example Tritan. The airflow passage 112 comprises a housing airflow outlet 114. The housing airflow outlet 114 is defined at a proximal end of the airflow passage 112 and the proximal end of the housing 100. The airflow passage 112 is positioned substantially centrally within the housing 110.
The cartridge 140 comprises the heater assembly 120, which comprises a heater holder 130, a porous body 132, and a heating element 134. The porous body 132 and the heating element 134 may together be referred to as a heater. The porous body 132 is a ceramic porous body configured to convey the liquid aerosol-forming substrate to the heating element 134. The porous body 132 comprises a heating surface on which the heating element 134 is positioned, and a back surface opposing the heating surface. The heating element 134 is an electrically resistive heating element. The heater is illustrated in more detail in Figures 5A and 5B.
As shown in Figure 1A, the heater holder 130 comprises two liquid channels 123, arranged on either side of an air outlet 122. The liquid channels extend between the liquid reservoir 116 and the porous body 132 to deliver liquid aerosol-forming substrate from the reservoir 116 to the porous body 132.
The heater holder 130 is positioned within and has an interference fit with the housing 110. The heater holder 130 has a sealing element 118, in this case a plurality of sealing ribs, provided on its outer surface for forming a seal with an inner surface of the housing 110 to seal the reservoir 116. The sealing element 118 is provided to prevent liquid aerosol-forming substrate from leaking out of the liquid reservoir and into a gap between the heater holder 130 and the housing 110.
The heater holder also comprises a plurality of channels 108 formed between the outer surface of the heater holder and the inner surface of the housing on an opposite side of the sealing element 118 to the reservoir 116. The plurality of channels 108 are formed by protrusions formed on the outer surface of the heater holder 130. If any liquid does pass from the reservoir 116 past the sealing element 118 or leaks from the porous body 132 into the gap between gap between the heater holder 130 and the housing 110, the plurality of channels 108 hold the liquid to reduce the risk of it leaking from the cartridge 140. This is more clearly illustrated in and described with reference to Figures 2 and 3.
The heater holder 130 further comprises a first cavity for supporting the porous body 132 and a second cavity which is in fluid communication with an air outlet 122. The air outlet 122 is in fluid communication with the heater holder outlet 127, which leads to the airflow passage 112.
An integral separating element 126 separates the first cavity from the second cavity, and the separating element 126 covers the back surface of the porous body to prevent fluid communication between the back surface of the porous body 132 and the air outlet 122.
The cartridge 140 further comprises two cartridge electrical contacts 138. The cartridge electrical contacts 138 are configured to be accessible from the lower surface of the cartridge. Each cartridge electrical contact 138 is further configured to contact either end of the heating element 134, illustrated in more detail in Figure 5A. The two cartridge electrical contacts 138 comprise copper with a gold coating.
The two cartridge electrical contacts 138 are arranged on either side of a central air inlet 142, which allows air to enter the cartridge 140 and heater assembly 120.
The power supply unit 150 comprises a device cavity. The device cavity is defined by the power supply unit and 150 and is configured to receive a portion of the cartridge 140 when the cartridge is coupled to the power supply unit 150. The cartridge 140 is configured to be reversibly coupled to the power supply unit 150 by snap fitting.
The power supply unit 150 further comprises device electrical contacts 155 located on a lower surface of the device cavity. The device electrical contacts 155 are configured to contact the cartridge electrical contacts 145 when the cartridge 140 is coupled to the power supply unit 150. The two device electrical contacts 155 comprise copper with a gold coating. The power supply unit 150 further comprises control circuitry 154. The device electrical contacts 155 are connected to the control circuitry 154 via electrical wires. The power supply unit 150 further comprises a power supply 156. The power supply 156 comprises a rechargeable lithium ion battery, that is rechargeable via an electrical connector (not shown) at a distal end of the power supply unit 150. The power supply 156 is connected to the control circuitry 154 via electrical wires.
Figure 1 B shows the aerosol-generating system 100 in a use configuration, wherein the cartridge 140 is coupled to the power supply unit 150. In use, the user may reversibly couple the cartridge 140 to the power supply unit 150 and decouple the cartridge 140 from the power supply unit 150, for example when the reservoir 116 is empty of liquid aerosol-forming substrate. The cartridge 140 may be coupled to the power supply unit 150 at a distal end of the cartridge by snap fitting.
When the cartridge 140 is coupled to the power supply unit 150, a small gap is present between the distal end of the cartridge 140 and the power supply unit 150. In use, air may enter the system air inlet 152. The system air inlet is in fluid communication with the air inlet 142.
When coupled to the power supply unit 150, a portion of the cartridge 140 is received within the device cavity, such that the device electrical contacts 155 are in contact with the cartridge electrical contacts 138. A complete electrical pathway is therefore formed from the device electrical contacts 155 to the cartridge electrical contacts 138, and then to the heating element 134.
In use, the user connects the cartridge 140 to the power supply unit 150 and presses a button (not shown) located on the side of the power supply unit 150 to activate the system. The button is connected to the control circuitry 154. The control circuitry 154 is configured to control the supply of power from the power supply 156 to the heating element 134 via the device electrical contacts 155 and the cartridge electrical contacts 138. When the user presses the button, power is supplied from the power supply 156 to the heating element 134, via the control circuity 154, the device electrical contact 155 and the cartridge electrical contacts 138, such that the temperature of the heating element 134 increases. The liquid aerosol-forming substrate in the reservoir 116 is drawn down the liquid passages 123 in the heater holder 130 to the porous body 132 of the heater assembly 120. The porous body 132 wicks the liquid aerosol-forming substrate to the heating surface of the ceramic body 132 where it is volatilised by the hot heating element 134.
When the user inhales upon the proximal end of the housing 110, air is drawn through the aerosol-generating system 100. In particular, air is drawn into the system through the system air inlet 152, and then through the cartridge air inlet 142. The air passes across the heating surface of the porous body 132 and the hot heating element 134, where the volatilised aerosol-forming substrate is entrained by the air. The volatilised aerosol-forming condenses within the flow of air through the cartridge 140 to form an aerosol. The airflow containing the aerosol travels past the porous body and through the air outlet 122. It is drawn into the mouth of the user via the airflow passage 112 and cartridge airflow outlet 114.
The flow of air 172 passes through the cartridge 140 approximately perpendicular to a longitudinal direction of the system 100. The longitudinal direction of the system 100 is substantially parallel to the direction of air flow from the porous body 132, through the airflow passage 112 and to the cartridge airflow outlet 114.
Figure 2 shows a schematic cross-sectional view of the heater holder 130 of the aerosol-generating system in Figure 1. The heater holder 130 is made from a thermoplastic elastomer having a Shore A hardness of 70. The heater holder 130 comprises a first cavity 124, a second cavity 128 and a separating element 126, which separates the first cavity 124 from the second cavity 128. The separating element 126 is integral to the heater holder 130.
The heater holder 130 comprises sealing elements in the form of parallel sealing ribs 118, 119. The sealing ribs 118, 119 are integral with and extend around an outer circumference of the heating holder 130 and are arranged to engage with the inner surface of another component of an aerosol-generating system, such as the housing 110 shown in Figure 1, to seal a liquid reservoir. First sealing ribs 118 are arranged to prevent liquid aerosol-forming substrate from leaking out of the liquid reservoir and into a gap between the heater holder 130 and the housing 110. The heater holder further comprises second sealing ribs119. The second sealing ribs are provided at an opposite end of the heater holder 130 to the first sealing elements 118. The second sealing ribs provide a further barrier to liquid escaping from the cartridge as well as a barrier to contaminants entering the cartridge.
Between the first sealing ribs 118 and the second sealing ribs 119 and plurality of protrusions 162 and formed on the outer surface of the heater holder. The protrusions 162 define a plurality of interconnected liquid channels 108. The liquid channels 108 acts to retain any liquid that leaks past the first sealing ribs 118 or from the porous body into the space between the heater holder and the housing. In this embodiment it can be seen that the protrusions comprise a plurality of parallel protrusions extending around a circumference of the heater holder. The parallel protrusions define a plurality of transverse liquid channels between them. Each of the transverse liquid channels is connected to one or two adjacent transverse channels by longitudinally extending channels formed between the protrusions. The protrusions extend close to the housing of the cartridge so that liquid is retained in the channels and cannot pass from one transverse channel to the next except through one of the longitudinal channels. It can be seen that each of the longitudinal channels connect only two adjacent transverse channels and are offset in a transverse direction from the vertical channels connecting to the next transverse channel. In this way, liquid travelling through the interconnected channels must traverse a serpentine or labyrinthine path. This is illustrated by the solid arrows in Figure 2. This increases the path length liquid needs to travel in order to reach the second sealing ribs 119 and thereby mitigates against liquid leakage from the cartridge. The channels formed between the protrusions have dimensions that may give rise to significant adhesion between the heater holder and any liquid aerosol-forming substrate in the channels and the formation of menisci in the channels. This can reduce the tendency of liquid aerosol-forming substrate to quickly flow through the channel structure. The material of the outer surface of the heater holder can also be chosen to enhance liquid adhesion.
It is possible for some or all of the protrusions defining liquid channels to be formed instead on the inner surface of the housing, as described with reference to Figure 5.
A porous body (not shown in Figure 2) is supported by the heater holder 130 in the first cavity 124. A separating element 126, integral with the heater holder 130, separates the porous body from the air outlet 122 and prevents liquid escaping from a rear surface of the porous body into the air flow.
Figure 3 shows a schematic isometric view of the heater assembly according to the present disclosure. The heater assembly 120 comprises the porous body 132, supported by a heater holder 130 within the first cavity 124 of the heater holder 130. The separating element 126 is in contact with and covers a back surface of the porous body 132.
The heater holder 130 comprises a holder outlet 127, which is in fluid communication with the air outlet 122 (not shown in Figure 4) . The heater holder 130 comprises two liquid passages 123 defined on either side of the holder outlet 127.
The liquid passages 123 are defined between the porous body 132 and the liquid reservoir of the aerosol-generating system. The liquid passages convey liquid from the liquid reservoir to the porous body 132.
The interconnected liquid channels 108 formed between the protrusions 162 are clearly illustrated in Figure 3.
The heater holder comprises two apertures defined through the heater holder on opposing sides of the heater holder 130. A first aperture is aligned with a third surface of the porous body 132 and a second aperture is aligned with a fourth surface of the porous body 132. The second aperture and fourth surface of the porous body 132 are on the opposite side of the heater holder 130, not visible in Figure 3. When present in an aerosol-generating system, a portion of the airflow pathway in contact with the third and fourth surfaces of the porous body is also in contact with other elements of the aerosol-generating system 100 outside of the heater holder 130, by way of the apertures aligned with the third surface and the fourth surface of the porous body.
Electrical contacts 338 are electrically connected to a heating element (not shown) that is positioned on the heating surface of the porous body 132.
In use, when the heater assembly 120 is present in an aerosol-generating system 100, the heater holder is arranged inside a housing as shown in Figures 1A and 1 B. The portions of the airflow pathway that are in contact with the third surface and fourth surface of the porous body 132 are also in contact with an inner surface of the housing.
Figure 4A shows a schematic isometric view of a heater comprising the porous body and heating element and Figure 4B shows a schematic alternative isometric view of the heater.
The heating element 134 is illustrated as arranged on the lower, heating, surface of the porous body 132. The heating element comprises two heating element electrical contacts 135 at opposite ends of the heating surface 131 of the ceramic body 132. The two heating element electrical contacts 135 are configured to contact the cartridge electrical contacts 138, as is described above.
The heating element 134 further comprises a serpentine heating element pathway 133 extending between the two heating element electrical contacts135. The serpentine heating element pathway 133 is configured to be resistively heated when a current is passed through the serpentine heating element pathway 133. The heating element 134 is a metallic track comprising a film of metal. The two heating element electrical contacts 135 are integrally formed with the serpentine heating element pathway 133. For example, the heating element 134 can be made of Ag-Pd alloy or Fe-Si alloy.
Two liquid feed cut-outs 136 are defined in the porous body 132. Each of the two liquid feed cut-outs 136 are defined in back surface 137 at opposite ends of the porous body 132.
When the porous body 132 is positioned in the heater holder 130, the liquid aerosol-forming substrate flows from the heater holder liquid channels 123 into the corresponding liquid feed cut-outs 136, and subsequently into the porous body 132.
Figure 5 is a schematic illustration of an alternative embodiment of the disclosure, in which the protrusions forming the liquid channels between the heater holder and the housing are part of the inner surface of the housing. In Figure 5, the housing 410 of the cartridge includes protrusions 462 on its inner surface 470. The protrusions 462 define the plurality of liquid channels. The heater holder 430 supports the heater 139. The heater holder 430 includes a first sealing rib 418 than engages the inner surface 470 of the housing 410 on the liquid reservoir side of the protrusions 462. The heater holder 430 includes a second sealing rib 419 than engages the inner surface 470 of the housing 410 on the opposite side of the protrusions 462 to the first sealing rib 418.
The pattern of protrusions in the embodiment of Figure 5 can take various forms. Figure 6A illustrates one embodiment in which the longitudinal channels connecting adjacent transverse channels are aligned with one another. In this case liquid may be able to travel quickly throughout the network of channels. This pattern could also be used in the embodiment of Figure 2 and 3.
Figure 6B illustrates a preferred arrangement of channels, as shown in Figure 2 and 3, in which the longitudinal channels connecting adjacent transverse channels are offset from one another. This creates a more complex liquid path from one end of the structure to another.
In both Figures 6A and 6B all of the liquid channels are interconnected. However, it is possible to arrange the protrusions to form two or more separate liquid channel structures that are not connected to one another. Furthermore, the channels in Figures 6A and 6B are aligned with the transverse and longitudinal directions of the system. However, this is not essential and some or all of the channels can be arranged to extend diagonally or along more complex, curved paths.

Claims

A cartridge for an aerosol-generating system, the cartridge comprising:

a housing, the housing defining a reservoir containing a liquid aerosol-forming substrate;

a heater, the heater comprising a heating element and a porous body, the heating element positioned on a heating surface of the porous body, the porous body configured to convey the liquid aerosol-forming substrate to the heating element; and

a heater holder, the heater holder supporting the heater within the housing and comprising one or more first sealing ribs on an outer surface that engage the housing to seal the reservoir; and

a plurality of channels formed between the outer surface of the heater holder and the housing on an opposite side of the first sealing ribs to the reservoir.
A cartridge according to claim 1, wherein the plurality of channels are formed by one or more protrusions formed on the outer surface of the heater holder.
A cartridge according to claim 1, wherein the plurality of channels are formed by one or more protrusions formed on the inner surface of the housing.
A cartridge according to claim 1, wherein the plurality of channels are formed by one or more protrusions formed on the outer surface of the heater holder and one or more protrusions formed on the inner surface of the housing.
A cartridge according to any one of the preceding claims, wherein the plurality of channels are serpentine channels.
A cartridge according to any one of the preceding claims, wherein the plurality of channels are interconnected with each other.
A cartridge according to any one of the preceding claims, wherein the plurality of channels comprise three or more transverse channels and a plurality of longitudinal channels, each of the transverse channels connected to an adjacent transverse channel by one or more longitudinal channels, and wherein each longitudinal channel connects only two transverse channels.
A cartridge according to any one of the preceding claims, wherein the channels comprise a first transverse channel, a second transverse channel and a third transverse channel, wherein second transverse channel is positioned between the first transverse channel and the third transverse channel, and wherein each longitudinal channel connecting the first transverse channel with the second transverse channel is offset in the transverse direction from each longitudinal channel connecting the second transverse channel with the third transverse channel.
A cartridge according to any one of the preceding claims, wherein the heater holder comprises one or more second sealing ribs on an opposite side of the channels to the first sealing ribs, the second sealing ribs engaging the housing.
A cartridge according to any one of the preceding claims, wherein the heater holder comprises liquid passages extending from the reservoir to the porous body.
A cartridge according to any one of the preceding claims, wherein the heater holder comprises an elastomeric material.
A cartridge according to any one of the preceding claims, wherein the heater holder exposes the heating surface to an airflow channel.
A cartridge according to any one of the preceding claims, wherein the heater holder exposes electrical contacts fixed to or integral with the heating element,
An aerosol-generating system, comprising:

a cartridge in accordance with any one of the preceding claims; and

a power supply unit configured to provide power to the heating element.
An aerosol-generating system, comprising:

a housing, the housing defining a reservoir containing a liquid aerosol-forming substrate;

a heater, the heater comprising a heating element and a porous body, the heating element positioned on a heating surface of the porous body, the porous body configured to convey the liquid aerosol-forming substrate to the heating element; and

a heater holder, the heater holder supporting the heater within the housing and comprising one or more first sealing ribs on an outer surface that engage the housing to seal the reservoir; and

a plurality of channels formed between the outer surface of the heater holder and the housing on an opposite side of the first sealing ribs to the reservoir.