Technical Field
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The present invention relates generally to aerosol generating systems. The invention relates particularly, but not exclusively, to cartomizers for aerosol generating systems that comprise a base part and a separable cartomizer.
Technical Background
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Aerosol generating systems, also commonly termed electronic cigarettes, are an alternative to conventional cigarettes. Instead of generating a combustion smoke, they vaporise a liquid aerosol generating substrate which can be inhaled by a user. The liquid typically comprises an aerosol generating substance, such as glycerine or propylene glycol, that creates the vapour when heated. Other common substances in the liquid are nicotine and various flavourings.
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In general terms, a vapour is a substance in the gas phase at a temperature lower than its critical temperature, which means that the vapour can be condensed to a liquid by increasing its pressure without reducing the temperature, whereas an aerosol is a suspension of fine solid particles or liquid droplets, in air or another gas. It should, however, be noted that the terms "aerosol" and "vapour" may be used interchangeably in this specification, particularly with regard to the form of the inhalable medium that is generated for inhalation by a user.
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An aerosol generating system is a hand-held inhaler system, typically comprising a mouthpiece section, a reservoir configured to hold liquid aerosol generating substrate in a reservoir chamber, and a power supply unit. Vaporisation is achieved in a vaporisation region, such as a vaporisation chamber, by a vaporiser or heater which typically comprises a heating element such as a resistive wire and a fluid transfer medium such as a fibrous wick. Vaporisation occurs when the heater heats the liquid in the wick until the liquid is transformed into vapour. The vapour is conveyed from the vaporisation region to an outlet in the mouthpiece section by means of a vapour outlet pathway.
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There are presently two main types of non-disposable aerosol generating system, namely: open tank systems and closed tank systems. Open tank systems are intended for multiple uses, and include a reservoir that is refillable by a consumer. As such, open tank systems have a relatively high initial cost to the consumer, since the components need to be engineered to have a relatively long life cycle. Furthermore, use of an open tank system requires technical know how and a certain willingness of the consumer to deal with sticky, potentially harmful, e-liquid when refilling the system. This can be off-putting for users who are unfamiliar with the usage of such systems.
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Closed tank systems, on the other hand, typically comprise a base part and a separable portion which includes the reservoir, and which is usually referred to as a cartridge or cartomizer. The base part of the system comprises control electronics and is reusable, but the reservoir in the cartridge/cartomizer is not refillable by the user, and is instead intended to be disposed of after use. Such systems thus typically have a lower initial cost than open tank systems because there is no requirement for the components of the disposable cartridge to have an extended lifespan. Closed tank systems are easy to use, and the e-liquids included in the cartridges for such systems can be considered as "certified" or safe because they have a known provenance and cannot be tampered with. For these reasons, closed tank systems are often preferred by users.
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The cartridges of closed tank systems may include a heating element and fluid transfer element in addition to a liquid reservoir, and in such circumstances are often referred to as cartomizers. The typical size of the reservoir in such a cartomizer is <2ml. This means that when the cartomizer is disposed of the components of the cartomizer, including the heating element and fluid transfer element, show almost no degradation. Thus, such cartomizers may be considered as wasteful in comparison with open tank systems by environmentally conscious consumers.
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It has been proposed to place the heating element in the base part of a closed tank device, whilst maintaining the fluid transfer element in a disposable cartridge with the liquid reservoir. Whilst this is more environmentally sustainable in that it permits reuse of the heating element, separating the heating element from the fluid transfer element in this way can introduce heat transfer inefficiencies between the heating element and the liquid held in the fluid transfer element.
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It is an object of the invention to address some or all of the above issues.
Summary
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According to a first aspect of the invention we provide a cartomizer for an aerosol generating system, the cartomizer comprising:
- a tank portion comprising:
- a reservoir housing having an opening, and
- a resilient gasket sealingly closing the opening,
- the reservoir housing and the resilient gasket together defining a reservoir chamber operable to contain a liquid aerosol generating substrate; and an atomiser portion comprising:
- an atomiser housing enclosing a vaporisation chamber,
- a fluid transfer element in fluid communication with the vaporisation chamber, and
- a piercing element comprising a liquid pathway;
- wherein the tank portion is removably connectable to the atomiser portion in such a way that the piercing element is caused to protrude into the resilient gasket in order to place the reservoir chamber in fluid communication with the fluid transfer element; and
- wherein the fluid transfer element is a single continuous component having a first portion located within the liquid pathway and a second portion located in the vaporisation chamber.
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As noted above, state of the art cartomizers can be expensive and create unnecessary waste, because the atomizer (being the combination of the heating element and the fluid transfer element) is replaced before its end of life. Splitting such a cartomizer into two parts, namely an atomiser portion including the heating element and fluid transfer element and a tank portion including the reservoir improves sustainability, because the atomiser portion may be reused with multiple disposable tank portions. The tank portions, being sealed and non-refillable, may be disposed of after each use in the same manner as traditional disposable cartomizers, thus retaining the ease of use and safety aspects of traditional closed tank systems. However, because of the simple construction of the tank portions, the tank portions may be more easily recycled than traditional cartomizers.
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Housing the atomiser in a separate disposable component also improves sustainability as compared with traditional open tank systems. This is because the heating element and/or fluid transfer element of a liquid-based aerosol generating system typically degrades over time during use. This degradation often occurs more swiftly than the degradation of other components of the system, such as the controller and battery. Thus, by providing the heating element and fluid transfer element in an atomiser portion which is separable from the base device, the atomiser portion may be replaced independently of the base device. This may result in a longer usable lifespan for the components of the base device, which need not be replaced together with the atomiser portion when the atomiser portion degrades.
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Providing an atomiser portion which is separable from a tank portion can result in engineering challenges when it comes to leakage prevention and liquid flow. This is because it is important for the tank portion to remain fluid-tight during transportation and storage. However, during usage, liquid must be able to flow freely from the reservoir in the tank portion to the vaporisation chamber in the atomiser portion in controlled and reliable manner. To this end, the atomiser portion described herein is provided with a piercing element having a liquid pathway. The piercing element is operable to protrude into a resilient gasket belonging to the tank portion when the tank portion is removably connected to the atomiser portion, so as to provide a route for fluid egress from the reservoir which directs fluid towards the vaporisation chamber in the atomiser portion.
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As fluid leaves the reservoir, air may flow into the reservoir in the opposite direction in order to balance the internal pressure within the reservoir. This can result in air bubbles forming inside the reservoir and/or liquid pathway, which can block, or at least reduce, the flow of fluid through the liquid pathway. This can be particularly problematic when bubbles form on the internal surfaces of the piercing element. In order to mitigate the formation of such air bubbles, a fluid transfer element is located inside the liquid pathway, such that a first portion of the fluid transfer element is held within the liquid pathway and a second portion of the fluid transfer element protrudes from the liquid pathway and into the vaporisation chamber. The fluid transfer element assists in wicking liquid from the reservoir through the piercing element in a controlled manner. The fluid transfer element also inhibits bubble formation inside the liquid pathway. Because the fluid transfer element is formed as a single continuous component (i.e. it is unitary, and not formed of more than one separable part), there are no discontinuities present which might inhibit the smooth flow of liquid or promote the formation of air bubbles. Finally, the fluid transfer element may also discourage liquid from leaking from the vaporisation chamber within the atomiser portion after use.
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The resilient gasket may further comprise a self-sealing aperture. The piercing element may be operable to protrude into the self-sealing aperture when the tank portion is removably connected to the atomiser portion. Use of a self-sealing aperture assists in maintaining liquid inside the reservoir, both during connection of the atomiser portion and the tank portion (i.e. prior to use) and during separation (i.e. after use). Occasionally a small amount of unused liquid may remain inside reservoir chamber after heating is completed, and such liquid may be maintained within the reservoir chamber by the self-sealing aperture as the piercing element is withdrawn from the resilient gasket during separation of the atomiser portion from the tank portion.
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The resilient gasket may comprise a fluid outlet pathway formed therethrough and having an outlet end operable to receive the piercing element when the piercing element is caused to protrude into the resilient gasket. The fluid outlet pathway may comprise the self-sealing aperture at the outlet end (also termed herein a distal end).
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The fluid outlet pathway may further comprise a funnel portion. The funnel portion may be shaped to direct fluid towards the outlet end of the fluid outlet pathway. For example, the funnel portion may be generally conical in shape, having a flared mouth tapering distally towards the outlet end. When the cartomizer is oriented in a use orientation, the funnel portion may comprise a lowest and/or most distal part of the reservoir chamber. The funnel portion may thus encourage fluid to flow towards the outlet end of the fluid outlet pathway in use, and thus towards the atomiser portion when the piercing element protrudes into the resilient gasket.
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The liquid pathway of the piercing element may be defined by a hollow internal channel extending through the piercing element. Thus the liquid pathway, and the fluid transfer element located therein, may be entirely encircled by, and so protected and supported by, one or more walls of the piercing element. This allows the fluid transfer element to be made from a flexible fibrous material, which may improve ease of wicking and/or may improve ease of air ingress to the reservoir chamber during use.
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The hollow internal channel of the piercing element may comprise non-parallel walls. For example, the hollow internal channel may taper such that an inlet end (also termed a proximal end) is narrower than an outlet end (also termed a distal end). By using a liquid pathway having a variable cross-section along its extension, the liquid transportation may be further improved.
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The first portion of the fluid transfer element may comprise a first longitudinal axis and the second portion of the fluid transfer element may comprise a second longitudinal axis, wherein the first longitudinal axis is not parallel to the second longitudinal axis such that the first longitudinal axis extends at an angle to the second longitudinal axis. Thus the fluid transfer element may be "bent" or "non-straight". By using a non-straight continuous fluid transfer element, a more compact construction may be achieved without compromising the efficiency of fluid transportation.
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The angle may be in the range 60°-120°, for example in the range 80°-100°, and preferably may be approximately 90°. Thus, the fluid transport element may be generally L-shaped. In this way, the vaporisation chamber may be located generally centrally within the atomiser portion, whilst the piercing element may be offset from the main longitudinal axis of the atomiser portion. This allows the fluid pathway through the atomiser to be more easily separated from the air/vapour path through the atomiser. It also permits a greater length of fluid transfer element to be provided in an atomiser portion having a given length, so providing increased thermal separation between the heated portion of the fluid transfer element and the unheated portion located in the liquid pathway of the piercing element.
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The piercing element may be formed of polymer material. Suitable example polymer materials include polypropylene (PP), polycarbonate (PC), polyesters (such as PET or PEN (polyethylene 2,6-naphthalate))) and co-polyesters (such as Tritan(=PCTG)). Polymer materials are typically cheap, recyclable, and easy to produce, thus further improving the sustainability of the cartridge. Furthermore, polymer materials typically have improved wetting/liquid transportation properties as compared with other potential candidate materials, such as metal, as the contact angle of metal vs e-liquid is much bigger than the contact angle of typical polymer materials vs e-liquid.
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The fluid transfer element may be supplied pre-wetted with liquid aerosol generating substrate. This may enhance user safety and/or ease of use, since if the fluid transfer element is delivered dry, it needs to be in contact with liquid in the reservoir chamber for a short time after connection with the tank portion to soak up liquid before use, so as to avoid dry puffing.
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The tank portion of the cartomizer may further include a vapour transfer channel extending between a vapour inlet and a vapour outlet. The resilient gasket may further include a vapour pathway in fluid communication with the vapour inlet of the vapour transfer channel. Thus the resilient gasket may provide a vapour pathway between the atomiser portion and the vapour outlet which is entirely separate from the liquid pathway between the reservoir chamber and the atomiser portion.
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The atomiser portion of the cartomizer may further include an atomiser outlet in fluid communication with the vaporisation chamber. The vapour pathway of the resilient gasket may be operable to place the atomiser outlet in fluid communication with the vapour inlet of the vapour transfer channel when the tank portion is removably connected to the atomiser portion. In this manner vapour generated in the vaporisation chamber may flow from the vaporisation chamber in the atomiser portion into the vapour transfer channel in the tank portion.
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The atomiser portion may further include an outlet channel protruding from the atomiser housing, wherein the atomiser outlet is located at a proximal end of the outlet channel. The outlet channel may be operable to protrude into the vapour pathway when the tank portion is removably connected to the atomiser portion. In this manner the potential for vapour to escape during use from the interface between the tank portion and the atomiser portion may be reduced.
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The tank portion may comprise a first mechanical fixture and the atomising portion may comprise a second mechanical fixture. The first and second mechanical fixtures may together cooperate to enable the tank portion to be removably connected to the atomiser portion. Any suitable mechanical fixture may be used, such as complementary screw threads, a bayonet fitting, a frictional fitting such as a push fit, or similar. Once connected, the tank portion and the atomiser portion cooperate to form a complete cartomizer, and may be used together with a base portion of an aerosol generating system in a conventional manner. The separation force required to separate the tank portion from the atomiser portion may be 50-200% higher than the force of the fixture holding the atomiser portion to a base part, so as to prevent unwanted separation of the tank and atomiser portions when the cartomizer is removed from the base part.
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The reservoir housing may be provided with a high barrier coating on an interior surface and/or on an exterior surface. Current packaging solutions for disposable cartridges are wasteful, as generally cartridges are packaged in primary packaging (e.g., blister packs) as well as a secondary packaging. This is because the barrier properties of typical polymer materials which are used to make cartridges are low, so as to provide insufficient protection against moisture and/or oxygen ingress over a typical expected shelf-life (e.g. 12 months). Thus, cartridges are typically packaged in primary packaging, which provides the bulk of the barrier properties. This primary packing is then enclosed or supported in shelf-ready secondary packaging such as cardboard, which provides product information and is in a format to enable shelf compatibility, but provides minimal barrier properties due to the low-barrier materials used and its open construction. By providing a high barrier coating on an interior and/or exterior surface of the reservoir housing the barrier properties of the tank portion may be improved, such that primary packaging may be dispensed with.
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The tank portion may further include a removable or pierceable barrier layer sealingly covering at least a portion of the resilient gasket. Preferably the removable or pierceable barrier layer sealingly covers the outlet end of the fluid outlet pathway of the resilient gasket (e.g. the self-sealing aperture). If present, the removable or pierceable barrier layer may also cover the vapour pathway through the resilient gasket. Use of a removable or pierceable barrier layer further improves the barrier properties of the tank portion in the absence of primary packaging, whilst still ensuring ease of useability. Suitable example materials that may be used to form the removable or pierceable barrier layer may include aluminium, plastics, or paper having a high-barrier coating, such as a plastics coating.
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The atomiser portion may further comprise an air inlet upstream of the vaporisation chamber. A leakage prevention feature may be located between the air inlet and the vaporisation chamber. The leakage prevention feature may be a one-way valve. In this manner liquid within the vaporisation chamber may be prevented from leaking out of the air inlet when the system is in use.
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The tank portion may further comprise an end cap located over the gasket. Such an end cap may secure the gasket in place.
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The atomiser portion preferably comprises a heater, such as a resistive heating element. The resistive heating element may be wound around the second portion of the fluid transfer element. This may promote effective heat transfer.
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It is to be appreciated that the cartomizer may further include any one or more components conventionally included in a cartomizer of an aerosol generating system, as discussed in the description below.
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According to a second aspect of the invention, we provide packaging comprising a plurality of tank portions and one or more atomiser portions, wherein each tank portion is removably connectable to the or each atomiser portion in order to assemble a cartomizer in accordance with the first aspect of the invention.
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More specifically, each tank portion may comprise:
- a reservoir housing having an opening, and
- a resilient gasket sealingly closing the opening,
- the reservoir housing and the resilient gasket together defining a reservoir chamber operable to contain a liquid aerosol generating substrate; and
the or each atomiser portion may comprise:
- an atomiser housing enclosing a vaporisation chamber,
- a fluid transfer element in fluid communication with the vaporisation chamber, and
- a piercing element comprising a liquid pathway;
- wherein the fluid transfer element is a single continuous component having a first portion located within the liquid pathway and a second portion located in the vaporisation chamber.
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Each tank portion may be removably connectable to the or each atomiser portion in such a way that the piercing element is caused to protrude into the resilient gasket in order to place the reservoir chamber in fluid communication with the fluid transfer element. A tank portion together with an atomiser portion may thus comprise a kit of parts for a cartomizer in accordance with the first aspect of the invention.
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The packaging may comprise an outer recyclable container, such as a cardboard container. Thus, the packaging may serve as secondary packaging for the tank portions and atomiser portion(s) within. The tank portions may serve as primary packing for a liquid aerosol generating substrate contained within the reservoir chamber.
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According to a third aspect of the invention, we provide an aerosol generating system comprising a base part, and a cartomizer in accordance with the first aspect of the invention.
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It is to be appreciated that the base part may include any one or more components conventionally included in a base part of an aerosol generating system, as discussed in the description below.
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According to a fourth aspect of the invention, we provide a method of assembling an aerosol generating system comprising connecting a tank portion to an atomiser portion to assemble a cartomizer in accordance with the first aspect of the invention, and connecting the atomiser portion to a base device to assemble the aerosol generating system.
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The features set out above may be combined together in any combination that is not explicitly excluded, and also with features selected from the detailed description below.
Brief Description of the Drawings
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There now follows a detailed description of the invention, by way of example only, with reference to the accompanying drawing, in which:
- Figure 1 shows a cross-section of a cartomizer for an aerosol generating system in a first state, the cartomizer including a tank portion removably connected to an atomiser portion;
- Figure 2 shows a cross-section of the cartomizer of Figure 1 in a second state, in which the tank portion is disconnected from the atomiser portion;
- Figure 3A illustrates the tank portion shown in Figures 1 and 2 in a top perspective view;
- Figure 3B illustrates the tank portion shown in Figures 1 and 2 in a bottom perspective view;
- Figure 3C illustrates the tank portion shown in Figures 1 and 2 in a bottom plan view;
- Figure 4 is an exploded cross-sectional view of the tank portion of Figure 3 showing the reservoir housing, resilient gasket and optional end cap;
- Figure 5 is a bottom perspective view of the reservoir housing of Figure 4;
- Figure 6 is a top perspective view of the optional end cap of Figure 4;
- Figure 7 shows perspective, side, top and cross-sectional views of the resilient gasket of Figure 4;
- Figure 8 shows a cross-sectional view of the atomiser portion of Figures 1 and 2 disconnected from a tank portion;
- Figure 9 is an exploded diagram showing the components of the atomiser portion of Figure 8; and
- Figure 10 schematically illustrates air/aerosol and liquid flow paths through the cartridge of Figures 1 and 2 when in the first (assembled) state.
Detailed Description
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As discussed above, conventional aerosol generating systems typically consist of a base part and a disposable cartridge. The base part constitutes the main body of the system, and typically contains a power source and control electronics, which may for example be operable to sense a user inhalation, control the power supply to initiate and regulate heating, and facilitate re-charging. The cartridge contains a reservoir of vaporisable liquid aerosol generating substrate (also referred to as an e-liquid), a fluid transfer element (also referred to as a wick) that is operable to transfer the liquid aerosol generating substrate from the reservoir to a vaporisation region, and a vapour transfer channel operable to direct air along a flow pathway from an air inlet to an aerosol outlet via the vaporisation region. A heater that is provided with power from the base part may also be included in the cartridge, and in such circumstances the cartridge is usually referred to as a cartomizer.
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Due to the necessity to have an air inlet and aerosol outlet, the cartridge/cartomizer by itself, and the e-liquid it contains, is open to the environment. Oxygen has a tendency to oxidise nicotine, reducing the nicotine concentration in the e-liquid, which consequently has an impact on product satisfaction and may result in deviation from the labelled value beyond what is acceptable from a quality and/or legal standpoint. Furthermore, e-liquids are typically comprised of hygroscopic components, such as propylene glycol and vegetable glycerine, as well as nicotine, which all have a tendency to absorb water, which can negatively influence the sensory experience.
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It is desirable that the quality and freshness of the e-liquid is maintained over the expected shelf-life of the e-liquid, which is typically 12 months or more. For current liquid cartridge/cartomizer systems, the overall barrier properties which dictate shelf life are achieved through external primary packaging. That is, the cartridge/cartomizer is sealed within primary packaging, which provides an improved barrierto gas and/or water ingress over that of the cartridge itself. To maintain an adequate shelf-life, such primary packaging needs to provide high/very-high barrier properties. Achieving this requires the use of high/very-high barrier materials for the primary packaging, such as PVDC coated plastic, multi-material plastic lamination, or metalized substrates. The recyclability of such packaging in widespread streams is not possible, even if the base substrate is paper-based, due primarily to the multi-material and inseparable construction, the use of toxic substances (e.g. PVDC), or the quantity of non-paper material being above the limits for recyclability in paper/board streams.
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Furthermore, state of the art cartomizers are themselves a source of unnecessary waste, because the atomiser (being the combination of the heating element and the fluid transfer element) is replaced before its end of life once the e-liquid within the cartomizer is used up.
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Figures 1 and 2 schematically show one example of a cartomizer 10 for an aerosol generating system, such as an electronic cigarette, which aims to address one or more of the above problems. The cartomizer 10 is removably connectable to a base part of a conventional aerosol generating system in a conventional manner. The base part and the connection thereto are thus not described in further detail herein.
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In the example shown in Figures 1 and 2, the cartomizer 10 includes a tank portion 12 and an atomiser portion 14. The tank portion 12 and the atomiser portion 14 are removably connectable, and as such have a first state, shown in Figure 1, in which the tank portion 12 and the atomiser portion 14 are assembled into the cartomizer 10, and a second state, shown in Figure 2, in which the tank portion 12 and the atomiser portion 14 are disconnected, and thus form a kit for the cartomizer 10. When assembled, the cartomizer has a first, proximal end 16, which comprises an aerosol outlet 18 and a second, distal end 20, which is intended for connection to a base part of an aerosol generating system in a conventional manner. A longitudinal axis 22 extends centrally through the cartomizer 10 between the proximal 16 and distal 20 ends.
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The tank portion 12 of the cartridge includes a reservoir housing 24 and a resilient gasket 26. The reservoir housing 24 has an opening 28, which in the example shown is in the distal end of the reservoir housing. The resilient gasket 26 is operable to sealingly close the opening 28, such that the reservoir housing 24 and the resilient gasket 26 together define a reservoir chamber 30 for containing therein a liquid to be vaporised. The liquid may comprise an aerosol generating substrate such as propylene glycol and/or glycerine and may contain other substances such as nicotine and acids. The liquid may also comprise flavourings such as e.g. tobacco, menthol or fruit flavour. In the example shown, the tank portion 12 additionally includes a vapour transfer channel 17 extending between a vapour inlet 19 and the vapour outlet 18 and an end cap 31 located over the gasket.
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The atomiser portion 14 of the cartomizer includes an atomiser housing 32, a fluid transfer element 34 such as a fibrous wick (e.g. cotton or glass fibre), and a piercing element 36. The atomiser housing 32 encloses a vaporisation chamber 38, and the piercing element 36 defines a liquid pathway 40 from the exterior of the atomiser to the vaporisation chamber. In the example shown, the liquid pathway 40 is defined by a hollow internal channel extending through the piercing element 36. The internal channel has a liquid inlet 40a at a proximal (i.e. reservoir-facing) end, through which liquid may enter the liquid pathway 40. The hollow internal channel has a generally circular cross section in the example shown, with a generally constant cross-section along its length resulting in generally parallel channel walls. In other examples however the internal channel may have a variable cross-section resulting in non-parallel walls. For example, the internal channel may taper, so as to be narrowest at the liquid inlet 40a.
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The fluid transfer element 34 is operable to place the liquid pathway defined by the piercing element 36 in fluid communication with the vaporisation chamber 38. The fluid transfer element 34 is a single continuous component, and has a first portion 34a located at least partially within the liquid pathway 40 and a second portion 34b located in the vaporisation chamber 38. In the example shown, the first portion 34a of the fluid transfer element defines a first longitudinal axis 35a and the second portion 34b of the fluid transfer element defines a second longitudinal axis 35b that is not parallel to the first longitudinal axis. Put another way, the first longitudinal axis 35a extends at an angle to the second longitudinal axis 35b, such that the fluid transfer element may be considered "bent" or "non-straight". More specifically, in the example shown, the fluid transfer element is generally L-shaped, and the first longitudinal axis 35a extends at an angle in the range 60°-120° to the second longitudinal axis 35b, for example in the range 80°-100°, such as approximately 90°. The first longitudinal axis 35a is generally parallel to but laterally spaced from the main longitudinal axis 22 of the cartomizer 10. At least the first portion 34a of the liquid transfer element has a cross-section that is complementary in shape to the cross-section of the liquid pathway, such that the first portion 34a fits tightly within the liquid pathway. In the example shown, the cross-section of both the first portion 34a and the liquid pathway are generally the same, and in this example are generally circular. In fact, the cross-section of the entire liquid transfer element is generally circular along its length, in the example shown.
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The atomiser portion also includes a heater 41, which in the example shown is a resistive heating element that is wound around the second portion 34b of the fluid transfer element 34. The heater is located in the vaporisation chamber 38, which itself is located generally centrally in the atomiser portion.
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In use, the tank portion 12 is removably connectable to the atomiser portion 14 in such a way that the piercing element 36 is caused to protrude into the resilient gasket 26 in order to place the reservoir chamber 30 in fluid communication with the fluid transfer element 34. In this manner, when the tank portion 12 is removably connected to the atomiser portion 14, liquid may flow from the reservoir chamber 30 to the vaporisation chamber 38 via the fluid transfer element 34.
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In the specific example shown in the Figures, the resilient gasket 26 defines a fluid outlet pathway 42 having an outlet end 42a (also termed herein a distal end) that is operable to receive the piercing element 36 when the tank portion is connected to the atomiser portion. A self-sealing aperture 43 is provided at the outlet end 42a of the fluid outlet pathway 42, such that when the piercing element protrudes into the fluid outlet pathway 42 leakage from the reservoir chamber 30 around the piercing element 36 is prevented, because the self-sealing aperture 43 seals tightly against the outer surface of the piercing element. A funnel portion 44 is provided at an inlet end 42b (also termed herein a proximal end) of the fluid outlet pathway 40, which is shaped to direct fluid from the reservoir chamber 30 towards the outlet end 42a of the fluid outlet pathway 42. In the example shown, the funnel portion 44 is generally conical in shape, and has a flared mouth that tapers distally towards the outlet end.
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The exemplary resilient gasket 26 also includes a vapour pathway 46 that is separate from the fluid outlet pathway 42 and laterally spaced from the fluid outlet pathway 42. Thus, the fluid outlet pathway 42 is located on a first side of the longitudinal axis 22 of the cartomizer, and the vapour pathway 46 is located in a second (opposite) side of the longitudinal axis 22. The vapour pathway 46 has an outlet end 46b (also termed herein a proximal end) in fluid communication with the vapour inlet 19 of the vapour transfer channel 17. The vapour pathway 46 additionally has an inlet end 46a (also termed herein a distal end) that is configured to receive vapour generated in the vaporisation chamber 38 of the atomiser portion 14 when the tank portion 12 is connected to the atomiser portion 14.
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The atomiser portion 14 of the cartomizer includes an atomiser outlet 48 in fluid communication with the vaporisation chamber 38. An outlet channel 50 protrudes from the atomiser housing 32. In the example shown, the atomiser outlet 48 is located at a proximal end of the outlet channel 50. The outlet channel 50 is operable to protrude into the vapour pathway 46 when the tank portion 12 is removably connected to the atomiser portion 14. Thus, the vapour pathway 46 is operable to place the atomiser outlet 48 in fluid communication with the vapour inlet 19 when the tank portion 12 is removably connected to the atomiser portion 14. In this manner, when the tank portion 12 is removably connected to the atomiser portion 14, vapour generated in the vaporisation chamber may flow from the vaporisation chamber 38 in the atomiser portion 14 into the vapour transfer channel 17 in the tank portion 12.
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Referring now to Figure 10, when the tank portion 12 is removably connected to the atomiser portion 14, the tank portion 12 and the atomiser 14 together form a cartomizer 10 which can be used to generate an inhalable aerosol when connected to a suitable base part (not shown). Due to the connection between the tank portion 12 and the atomiser portion 14, the fluid transfer element 34 of the atomiser portion 14 is located in fluid communication with the reservoir chamber 30 of the tank portion 12, and is configured to draw vaporisable liquid from the reservoir chamber 30 through the liquid pathway 40 of the piercing element 36 towards the heater 41 in the vaporisation chamber 38. Fluid is thus able to flow from the reservoir chamber 30 to the vaporisation chamber 38 along a fluid flow path 53.
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The vaporisation chamber 38 is also in fluid communication with an air flow pathway 54 through the aerosol generating system, defined by the vapour transfer channel 17, the vapour pathway 46 and a cartridge inlet 56. When the base part is attached to the assembled cartridge 10, power may be supplied to the heater 41 in the atomiser portion 14 from a battery included in the base part via heater contacts 52 to heat up liquid in the vaporisation chamber 38, thereby generating a vapour. A user of the system may draw on the vapour outlet 18 (optionally via a mouthpiece) to encourage air to flow along the air flow pathway 54; that is, to encourage air to flow from the inlet 56, through the vaporisation chamber 38, through the vapour pathway 46 and the vapour transfer channel 17 towards the outlet 18. Vapour entrained in the airflow cools and condenses in the vapour transfer channel 17 to form an aerosol for inhalation by the user through the outlet 18.
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The piercing element 36 of the atomiser portion thus acts as a nozzle to deliver liquid from the reservoir to the vaporisation chamber. The internal channel defining the liquid pathway through the nozzle has a relatively large diameter, in the order of 2-4mm. When liquid is removed from the tank portion, air bubbles use the same path (in the opposite direction) to equilibrate the pressure in the reservoir chamber. These air bubbles may easily become trapped inside the nozzle, so blocking liquid egress from the reservoir chamber. This is particularly the case for a polymer nozzle, as polymer materials are typically hydrophilic. Inserting a portion of the fluid transfer element 34 into the liquid pathway 40 inside the nozzle mitigates this problem by promoting liquid supply through the nozzle by capillary force.
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Once the tank portion 12 and atomiser portion 14 are connected, and liquid is delivered to the vaporisation chamber 38, there is a risk of liquid leaking from the atomiser portion 14 either via the piercing element 36 or via the air inlet 56. Locating the fluid transfer element 34 inside the piercing element 36 supresses leakage to a certain degree, even in cases when the atomiser portion 14 is oriented upside down. In addition, a leakage prevention feature may be included upstream of the atomiser portion 14 and downstream of the air inlet 56, such as a one way valve 64, to discourage leakage from the inlet 56.
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In the example shown in the Figures, the reservoir housing 24 and the atomiser housing 14 (including piercing element 36) are formed (e.g. injection moulded) of a polymer material such as thermoplastics. The resilient gasket 26 is, in the example shown, formed of an elastomeric sealing material such as silicone rubber, and is sized to fit tightly within the opening 28 of the reservoir housing, for example using a frictional fit. One or more stops 58 may be provided on the interior of the reservoir housing to prevent over-insertion of the resilient gasket 26. Similarly, the resilient gasket 26 may include one or more shoulders 60 operable to impact an end face 62 of the reservoir housing in order to prevent over-insertion, and to form a tight seal.
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In the specific example shown, the resilient gasket 26 is a moulded silicone rubber (VMQ) with Shore A hardness of 30-80, preferably 50-60. The self-sealing slit described above may have a thickness of 1-3mm. Alternatively, a duckbill valve moulded from VMQ with hardness of 30-70 can be used either as integral part of the gasket or as separate part. The resilient gasket 26 may be over moulded to close the opening of the reservoir housing, or may alternatively glued or press-fit and fixed with an end cap 31, such as a metal sleeve. The completed tank portion 12 may be filled through the resilient gasket 26 after connection of the reservoir housing 24 with the gasket 26.
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After filling, the resilient gasket 26 can be sealed with a removable or breakable high barrier layer (not shown) such as an aluminium foil seal. The seal does not necessarily need to be removed before using the tank portion, since the liquid feed nozzle (piercing element 36) can pierce through such a barrier layer in a similar manner to a straw. Such a barrier layer may provide an effective seal against oxygen and/or moisture ingress to the reservoir chamber 30 via the fluid outlet pathway of the resilient gasket.
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The tank portion may also be barrier coated against oxygen and water ingress, preferably on an inner surface and/or outer surface of at least the reservoir chamber. Again, this may provide effective protection against oxygen and/or moisture ingress to the reservoir chamber 30 via the material of the reservoir housing itself.
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Splitting the cartomizer into an atomiser portion (including wick and heater) and a tank portion (including e-liquid reservoir) in this manner, provides a less wasteful solution to a closed tank system. A single packaging unit may contain several tank portions and a single atomiser portion, where the heater in that atomiser portion has an expected life that is sufficient to generate an inhalable vapour from the collective volume of e-liquid included in the tank portions. The simple tank portions (2 polymer materials used plus aluminium sealing layer) can be produced with good barrier properties and fully sealed, thus negating the need for further primary packaging to protect the liquid and prevent leakage. Due to their simple construction the tank portions may be more easily recycled than traditional cartomizers.
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Although exemplary embodiments have been described in the preceding paragraphs, it should be understood that various modifications may be made to those embodiments without departing from the scope of the appended claims. Thus, the breadth and scope of the claims should not be limited to the above-described exemplary embodiments. Any combination of the above-described features in all possible variations thereof is encompassed by the present disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.