Packaging for aerosol generating systems

Abstract

A cartridge (14) for an aerosol generating system comprises: a reservoir chamber (24) for holding a liquid aerosol generating substrate; a cartridge housing (22) enclosing the reservoir chamber, and having one or more inlets (32) and one or more outlets (34); a vaporisation area (28) in fluid communication with the reservoir chamber (24); a vapour transfer channel (30) in communication with the vaporisation area (28), the vapour transfer channel (30) connecting the one or more inlets (32) to the one or more outlets (34); and one or more electrical connections (38a, 38b); wherein the cartridge housing (22) is formed from a metal material; and wherein the cartridge comprises at least one removable or breakable high barrier layer (42, 44, 420, 440) sealingly covering the one or more inlets (32), the one or more outlets (34) and the one or more electrical connections (38a, 38b). The cartridge may define primary packaging for an aerosol generating substrate.

Description

[0001] PACKAGING FOR AEROSOL GENERATING SYSTEMS

[0002] Technical Field

[0003] The present invention relates generally to packaging for aerosol generating systems. The invention relates particularly, but not exclusively, to packaging for cartridges for aerosol generating systems that comprise a base part and a separable cartridge.

[0004] Technical Background

[0005] 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 forming substance, such as glycerin or propylene glycol, that creates a vapour when heated. Other common substances in the liquid are nicotine and various flavourings.

[0006] 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.

[0007] 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 unit which typically comprises a heating element, such as a resistive heating coil, and a fluid transfer medium, such as a wick. Vaporisation occurs when the heating element heats the liquid in the fluid transfer element 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.

[0008] WO 2017 / 179043 discloses an example of an aerosol generating system comprising a replaceable cartridge and a reusable base part. The cartridge has a simplified structure which is achieved by keeping the main heating element and associated power source in the reusable base part, while the cartridge is provided with a heat transfer unit. The heat transfer unit is configured to transfer heat from the heating element in the base part to the proximity of liquid aerosol generating substrate in the cartridge to produce a vapour for inhalation by a user. Other aerosol generating systems instead include the main heating element in the replaceable cartridge, power to which is supplied by a power source located in a reusable base part via suitable electrical connections.

[0009] Liquid aerosol generating substrate typically degrades over time if it is exposed to air (and particularly oxygen within the air) and / or water. Many current cartridges require an open design however, in order to provide an air flow pathway through the cartridge for mixing with the vaporised aerosol generating substrate. This requirement exposes the liquid aerosol generating substrate within the cartridge reservoir to the external environment, because the vaporisation region, which is in fluid communication with the reservoir chamber holding the liquid aerosol generating substrate, is necessarily also in fluid communication with the air inlets and outlets of the cartridge.

[0010] The material that is used to form a cartridge for an aerosol generating system, and in particular the reservoir of such a cartridge, has challenging requirements. One such requirement is high chemical resistance, which is needed to prevent migration of harmful chemical components or substances to the aerosol generating substrate in quantities which would change the composition of the aerosol generating substrate and / or the resulting aerosol, potentially increasing the risk for consumers. As well as having high chemical resistance, the material should be cost-effective and compatible with high-volume manufacturing. The traditional candidate materials which meet these requirements, such as thermoplastics, do not provide sufficient barrier properties to maintain aerosol generating substrate freshness or quality at thicknesses that are acceptable from the point of view of cost or consumable size (wall thicknesses should be less than 2 mm, and preferably less than 1 mm). Typical materials used for cartridge housings, such as polypropylene (PP), polycarbonate (PC), polyesters (such as PET or PEN (polyethylene 2,6-naphthalate))) and co-polyesters (such as Tritan), only provide medium to low gas and / or vapour barrier properties.

[0011] Due to the low barrier properties of typical cartridge housings, such cartridges are not suitable for storing for an extended period. Packaging with higher barrier properties is therefore needed in order to obtain an acceptable shelf life, which may need to be up to 12 months, or longer.

[0012] Such packaging usually consists of two separate elements:

[0013] 1) Primary packaging in the form of a blister pack or plastic flow-wrap. This provides the bulk of the barrier properties, and is typically manufactured from materials with very high barrier properties, such as polyvinylidene chloride (PVDC) coated PET in a blister pack format containing multiple refill cartridges or flow-wrap having very high barrier properties surrounding individual cartridges.

[0014] 2) Shelf-ready secondary packaging. This provides product information and is in a format to enable shelf compatibility, such as cardboard with folds for receiving the cartridgecontaining blister pack. This secondary packaging provides minimal barrier properties due to the low barrier materials used and its open construction.

[0015] The need to provide multiple types of packaging in order to achieve satisfactory barrier properties and shelf life can be both wasteful and environmentally unfriendly, since the primary packaging in particular can be difficult to recycle. Utilising less packaging would contribute to a product that is more sustainable and also cheaper to produce.

[0016] Summary

[0017] According to a first aspect of the invention we provide a cartridge for an aerosol generating system, the cartridge comprising: a reservoir chamber for holding a liquid aerosol generating substrate; a cartridge housing enclosing the reservoir chamber, and having one or more inlets and one or more outlets; a vaporisation area in fluid communication with the reservoir chamber; a vapour transfer channel in communication with the vaporisation area, the vapour transfer channel connecting the one or more inlets to the one or more outlets; and one or more electrical connections; wherein the cartridge housing is formed from a metal material; and wherein the cartridge comprises at least one removable or breakable high barrier layer sealingly covering the one or more inlets, the one or more outlets and the one or more electrical connections.

[0018] A cartridge of the type described above provides significantly improved barrier properties as compared with a conventional plastics material cartridge. The improved barrier properties are achieved by two features which interact synergistically to ensure the cartridge provides a high barrier enclosure for an aerosol generating substrate stored within. Firstly, the cartridge housing, which forms the external body of the cartridge, is made of a metal material. Such materials inherently have significantly higher barrier properties than conventional candidate plastics materials. Secondly, at least one removable or breakable high barrier layer is provided sealingly covering the cartridge inlets, outlets and electrical connections. The cartridge inlets, outlets and electrical connections all provide potential routes for air ingress to the interior of the cartridge, and so by sealingly covering these points of ingress with a removable or breakable high barrier layer the interior of the cartridge may be substantially isolated from the external environment.

[0019] The removability or breakability of the high barrier layer ensures that a user is easily able to access the inlets, outlets and electrical connections when the user desires to connect the cartridge to a base part of the aerosol generating system. An example of a removable high barrier layer may be a peelable high barrier layer, such as a sticker that is removably attached to a surface of the cartridge housing, such as an external surface, using an impermanent adhesive. An example of a breakable high barrier layer may be a layer that is secured to a surface of the cartridge housing, such as an internal or external surface, in a substantially permanent manner (e.g. be adhesive or welding, or similar), and which is configured to be pierceable or frangible by a user. Thus, a breakable layer should be sufficiently thin that a user is able to break the layer without applying undue force, e.g. by hand or by connecting the cartridge to a complementary base part, and / or may include one or more predetermined points of weakness.

[0020] Providing a cartridge having improved barrier properties means that separate primary packaging may be dispensed with. That is, the cartridge itself may serve as primary packaging for an aerosol generating substrate, such that no external primary packaging, such as a blister pack or flow wrap, is needed to preserve the quality of the aerosol generating substrate for an acceptable shelf life (e.g. 12 months or more). Furthermore, a metal housing may be easier and / or more cost effective to recycle at end of life than a plastics housing, and may be more conducive to production from recycled materials. Such a cartridge may therefore be more sustainable to both produce and to dispose of than conventional plastics cartridges.

[0021] The cartridge may further include a vaporising unit including a fluid transfer element and a heating element. The fluid transfer element may be in fluid communication with the reservoir chamber, and operable to transfer liquid aerosol generating substrate from the reservoir chamber towards the vaporisation area. The heating element may be operable to heat liquid aerosol generating substrate present in the vaporisation area to generate an inhalable aerosol. Such an arrangement provides for a vaporisation area that is separate from the reservoir chamber and to which heat and fluid may be supplied in a controllable manner, so allowing for consistent vapour production throughout a usage session. However, such an arrangement presents a particular difficulty in maintaining the freshness of a liquid stored within the reservoir, since a fluid transfer path between the reservoir and the vaporisation area necessarily intersects at the vaporisation area with a vapour transfer path between the one or more inlets and the one or more outlets, so providing a potential route for air ingress to the reservoir chamber via the fluid transfer path. The electrical connections providing power to the heating element also provide a potential route for unwanted air ingress to the vaporisation unit, and so to the reservoir chamber via the fluid transfer path. A removable or breakable high barrier layer sealingly covering the one or more inlets, the one or more outlets and the one or more electrical connections thus has particular utility in a cartridge of this type.

[0022] The at least one high barrier layer may have an oxygen transmission rate, OTR, of less than 20 cm3 / m2 / 24hr, and preferably has an oxygen transmission rate, OTR, of less than 6 cm3 / m2 / 24hr. The at least one high barrier layer may have a water vapour transmission rate, WVTR, of less than 20 g / m2 / 24hr, and preferably has a water vapour transmission rate, WVTR, of less than 6 g / m2 / 24hr. Suitable example materials that may be used to form the at least one high barrier layer may include aluminium, plastics, or paper having a high-barrier coating, such as a plastics coating. Aluminium provides a very high barrier to both oxygen and water ingress, and may be easily recycled in existing recycling streams. Coated paper may be recycled in existing paper recycling streams, and even if not recycled still presents a significant reduction in non-recyclable waste as compared with the use of separate primary packaging. Furthermore, a plastics or coated paper layer may provide a visual distinction from the metal cartridge housing, which may assist in indicating to the user that the layer should be removed or broken.

[0023] The metal cartridge housing may have an oxygen transmission rate, OTR, of less than 1 cm3 / m2 / 24hr, and preferably has an oxygen transmission rate, OTR, of less than 0.1 cm3 / m2 / 24hr, or less than 0.01 cm3 / m2 / 24hr. The metal cartridge housing may have a water vapour transmission rate, WVTR, of less than 1 g / m2 / 24hr, and preferably has a water vapour transmission rate, WVTR, of less than 0.1 g / m2 / 24hr, or less than 0.01 g / m2 / 24hr. Suitable example metal materials may include aluminium or steel, such as stainless steel. As noted above, aluminium provides a very high barrier to both oxygen and water ingress, and may be easily recycled in existing recycling streams.

[0024] The at least one removable or breakable high barrier layer preferably has a closed perimeter in sealing connection with a surface of the metal cartridge housing. Each of the at least one inlets, at least one outlets, and at least one electrical connections is preferably located within a closed perimeter of the at least one removable or breakable high barrier layer, such that the at least one removable or breakable high barrier layer is in intimate contact with the cartridge housing in a closed perimeter around each of the at least one inlets, at least one outlets, and at least one electrical connections. Each of the at least one inlets, at least one outlets, and at least one electrical connections may be provided with a separate high barrier layer. Alternatively, one or more of the at least one inlets, at least one outlets, and at least one electrical connections may share a high barrier layer.

[0025] The cartridge may comprise a first removable or breakable high barrier layer seal ing ly covering the one or more inlets. The first removable or breakable high barrier layer may sealingly cover the one or more electrical connections as well as the one or more inlets. That is, a single high barrier layer may cover both the inlets to the cartridge housing and the electrical connections of the cartridge housing. The cartridge may comprise an interface surface that is operable, in use, to face and / or abut a corresponding interface surface on a base part. The one or more inlets and the one or more electrical connections may be located in said interface surface, and the first removable or breakable high barrier layer may sealingly cover the interface surface. In this way, only a single removable or breakable high barrier layer needs to be removed or fractured by the user in order to connect the cartridge with the base part of the system.

[0026] The first removable or breakable high barrier layer may be a peelable layer, or may be a breakable layer, and is preferably a peelable layer.

[0027] The first removable or breakable high barrier layer may additionally sealingly cover the one or more outlets. That is, a single high barrier layer may cover all the potential points of air ingress to the cartridge housing, namely the inlets, outlets and the electrical connections. In this way a user need only remove a single high barrier layer in order to use the cartridge.

[0028] Alternatively, the cartridge may further comprise a second removable or breakable high barrier layer sealingly covering the one or more outlets. The use of two separate removable or breakable high barrier layers may reduce the amount of material needed for the high barrier layers. The cartridge may comprise a mouthpiece region, and the one or more outlets may be provided in the mouthpiece region. The second removable or breakable high barrier layer may sealingly cover the mouthpiece region as well as the one or more outlets. In this way, the mouthpiece region may be maintained in a sanitary condition even in the absence of external primary packaging.

[0029] The second removable or breakable high barrier layer may be a peelable layer, or may be a breakable layer, and is preferably a peelable layer.

[0030] The vapour transfer channel of the cartridge may be formed of a metal material, and preferably is formed of the metal material (being the same metal material as the cartridge housing). This further increases the recyclability of the cartridge by increasing the volume of metal material and decreasing the corresponding volume of non-metal material present in the cartridge. Depending on the internal configuration of the cartridge, the vapour transfer channel may be formed partially of the metal material (e.g. a vapour outlet channel of the vapour transfer channel may be formed of the metal material), or the vapour transfer channel may be formed entirely of the metal material.

[0031] The vapour transfer channel and / or and the cartridge housing may define one or more walls of the reservoir chamber. The walls of the reservoir chamber may be coated with a barrier coating, such as an epoxy lacquer or polymer, to inhibit interaction between an aerosol generating substrate present in the reservoir chamber and the metal material.

[0032] It is to be appreciated that the cartridge may include any one or more components conventionally included in a cartridge of an aerosol generating system, as discussed in the description below.

[0033] According to a second aspect of the invention, we provide an aerosol generating system comprising a base part and a cartridge in accordance with the first aspect of the invention.

[0034] 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.

[0035] According to a third aspect of the invention, we provide packaging for an aerosol generating substrate, the packaging comprising an outer recyclable container and the cartridge of the first aspect of the invention, wherein the cartridge defines primary packaging for the aerosol generating substrate and the recyclable container defines secondary packaging for the aerosol generating substrate. The recyclable container is preferably formed of cardboard material.

[0036] The packaging may comprise a plurality of cartridges according to the first aspect of the invention. At least two of the plurality of cartridges may share a removable or breakable high barrier layer, for example such that the shared high barrier layer is separately removable from each of the at least two cartridges. The shared high barrier layer may assist in maintaining the plurality of cartridges in a predefined orientation with respect to one another whilst inside the cardboard container, in the absence of traditional primary packaging. The packaging may comprise a first shared high barrier layer sealingly covering the one or more inlets and the one or more electrical connections of each of the plurality of cartridges. Each cartridge may comprise a respective separate second high barrier layer sealingly covering the one or more outlets of that cartridge. Alternatively, the packaging may comprise a second shared high barrier layer sealingly covering the one or more outlets of each of the plurality of cartridges. In the case that the packaging comprises a second shared high barrier layer, each cartridge may comprise a respective separate first high barrier layer sealingly covering the one or more inlets and the one or more electrical connections of that cartridge.

[0037] The packaging may additionally include a base part for the aerosol generating system.

[0038] As used herein, the term “aerosol generating system” may include an aerosol generating system configured to deliver an aerosol to a user, including an aerosol for inhalation / vaping. An aerosol for inhalation / vaping may refer to an aerosol with particle sizes of 0.01 to 20 pm. The particle size may be between approximately 0.015 pm and 20 pm. The aerosol generating system may be portable.

[0039] 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.

[0040] Brief Description of the Drawings

[0041] There now follows a detailed description of the invention, by way of example only, with reference to the accompanying drawing, in which:

[0042] Figure 1 schematically shows an aerosol generating system including a base part and replaceable cartridge;

[0043] Figure 2 illustrates five example cartridge constructions;

[0044] Figure 3 illustrates four example barrier sticker arrangements; and

[0045] Figure 4 schematically shows a packaging system for an aerosol generating substrate including an outer container and a replaceable cartridge.

[0046] Detailed Description

[0047] 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 (also referred to as a pod) 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 heating system that is provided with power from the main device may also be included in the cartridge.

[0048] Due to the necessity to have an air inlet and aerosol outlet, the cartridge by itself, and the e- liquid it contains, is open to the environment. As explained above, 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 glycerin, as well as nicotine, which all have a tendency to absorb water, which can negatively influence the sensory experience.

[0049] 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. As explained above, for current liquid cartridge systems, the overall barrier properties which dictate shelf life are achieved through external primary packaging. That is, the cartridge is sealed within primary packaging, which provides an improved barrier to 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, (e.g. average material properties of OTR < 6 cm3 / m2 / 24hr, WVTR < 6g / m2 / 24hr). 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.

[0050] Figure 1 schematically shows one example of an aerosol generating system 10 that aims to address the situation described above. The aerosol generating system includes a base part 12 and a cartridge 14. The cartridge 14 is removably connectable to the base part 12, and is recyclable (as will be discussed in more detail below).

[0051] The base part 12 comprises a housing 16 enclosing a power supply unit such as a rechargeable battery 18. The aerosol generating device 10 further includes a controller 20, and may further include a user interface (not shown) for permitting a user to control the operation of the aerosol generating device 18 via the controller 20.

[0052] The cartridge 14 includes a housing 22, which encloses a liquid storage reservoir defining a reservoir chamber 24 configured for containing a vaporisable liquid aerosol generating substrate. The liquid may comprise an aerosol-forming substance such as propylene glycol and / or glycerin 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.

[0053] The cartridge 14 further includes a vaporising unit 26. In the example shown in Figure 1 , the vaporising unit 26 comprises a heating element, such as a resistive heating wire, and a fluid transfer element, such as a ceramic or fibrous wick. The heating element and fluid transfer element can take any form, and so are not illustrated in detail in Figure 1 .

[0054] The vaporising unit 26 is supported in the housing 22 by a supporting and sealing structure 27. The vaporising unit 26 and the supporting and sealing structure 27 together close the base of the reservoir chamber 24, in order to seal the liquid aerosol generating substrate inside.

[0055] The fluid transfer element of the vaporising unit 26 is in fluid communication with the reservoir chamber 24, for example by way of one or more fluid outlets located in the supporting and sealing structure 27. Vaporisable liquid from the reservoir chamber 24 which enters the fluid transfer element is wicked towards a vaporisation region 28, in which it may be vaporised by the heating element. A fluid transfer path is thus defined by the fluid transfer element that extends between the reservoir chamber 24 and the vaporisation region 28.

[0056] A vapour transfer channel 30 extends from one or more air inlets 32 through and / or past the vaporisation zone 28, to one or more aerosol outlets 34. A vapour transfer path is thus defined by the vapour transfer channel 30 that extends between the one or more air inlets 32, through and / or past the vaporisation region 28, towards the one or more aerosol outlets 34. The vapour transfer path intersects with the fluid transfer path at the vaporisation region 28, but is otherwise separate from the fluid transfer path.

[0057] In the example shown in Figure 1 , the cartridge includes a single centrally located inlet and a single centrally located outlet. The vapour transfer channel 30 includes a vapour outlet channel 36, being the portion of the vapour transfer channel 30 which is downstream of the vaporisation unit 26. In the example shown in Figure 1 , the vapour outlet channel 36 extends through the reservoir, such that the reservoir chamber 24 is disposed around the vapour outlet channel 36. The vapour outlet channel 36 and the cartridge housing 22 thus together define the walls of the reservoir chamber 24, which has a generally annular cross-section. The vapour transfer channel 30 extends centrally through the cartridge housing 22 between the inlet 32 and the outlet 34, and is aligned with a longitudinal axis of the cartridge 14.

[0058] The cartridge further includes one or more electrical connections 38, and in this example includes two electrical connections 38a, 38b. When the base part 12 is attached to the cartridge 14 the one or more electrical connections 38 cooperate with one or more electrical connections 40, and in this example two electrical connections 40a, 40b, on the base part 12. Power may be supplied to the vaporisation unit 26 from the battery 18 via the electrical connections 38, 40 to cause the vaporisation unit to heat up liquid in the vaporisation zone 28 thereby generating a vapour.

[0059] During use of the system, a user may draw on a mouthpiece attached to the cartridge or forming part of the cartridge in order to encourage air to flow along an airflow path defined by the vapour transfer channel 30; that is, to encourage air to flow from the inlet 32, through the vaporisation zone 28, and towards the outlet 34. Vapour entrained in the airflow cools and condenses in the vapour outlet channel 36 to form an aerosol for inhalation by the user through the outlet 34.

[0060] The cartridge 14 shown in Figure 1 differs from a conventional cartridge in that the cartridge 14 is operable to provide a high or very high barrier function, in order to provide a sufficient level of barrier resistance to achieve an acceptable shelf-life (such as a 12 month shelf-life). In this way, the cartridge 14 itself serves as primary packaging for an aerosol generating substrate held in the reservoir chamber 24, such that no external primary packaging is needed.

[0061] The cartridge 14 comprises two main features which together cooperate to provide this high- barrier function.

[0062] Firstly, the cartridge housing 22 is formed of a metal material, such as aluminium or stainless steel. Thus, the bulk of the cartridge, including one or more cartridge side wall(s) 22a, an upper surface 22b and a lower surface 22c are formed of metal material. All or a portion of the vapour transfer channel 30 may also be formed of a metal material, and in the example shown in Figure 1 , the vapour outlet channel 36 is formed of aluminium as well as the cartridge housing 22. A metal material, such as aluminium or stainless steel, provides a significantly improved barrier to both air and water ingress over that provided by traditional plastics materials. For example, a cartridge housing made of a metal material may have an oxygen transmission rate, OTR, of less than 1 cm3 / m2 / 24hr and water vapour transmission rate, WVTR, of less than 1 g / m2 / 24hr. In the case of aluminium, the OTR may be less than 0.01 cm3 / m2 / 24hr and the WVTR may be less than 0.01 g / m2 / 24hr, representing a significant improvement over conventional thermoplastics materials.

[0063] In contrast, existing plastic cartridge housings do not provide adequate barrier protection for an aerosol generating substrate. Housing thicknesses are usually in the approximate range 0.5mm to 1.0mm, which typically results in oxygen transmission rates (OTR) and water vapor transmission rates (WVTR) at least an order of magnitude greater than what is required to maintain the e-liquid freshness over the pods shelf life.

[0064] Furthermore, a cartridge formed primarily of metal material has significantly improved sustainability as compared with conventional plastics material cartridges. In particular, aluminium (and other metal) is 100% recyclable, meaning 100% of the recycled material can be turned into a new product with zero waste. Aluminium (and other metal) can also be infinitely recycled, i.e. recycled over and over again, without degradation of its inherent value or properties. 75% of the aluminium that has ever been made is still in use - this is because the metal can be recycled over and over again. Unlike plastics recycling, metal recycling is an efficient and energy saving process. In the case of aluminium, recycling requires only 5% of the energy needed to make primary aluminium for the first time. Finally, metal, and in particular aluminium, already has a widespread recycling infrastructure globally (due to the above benefits), making integration and practical recycling of metal cartridges realistic.

[0065] In contrast, recycling conventional plastics material cartridges can be challenging, as the plastics used in such cartridges are typically a niche grade, as opposed to more common grades such as PET, ABS or PP, and thus are not well supported by widespread recycling infrastructure. Even where suitable infrastructure exists, cartridge housings can often be contaminated by e-liquid, and end up being down-cycled over time (i.e. used in less demanding applications once recycled). Such down-cycled plastic may be unsuitable for use in manufacture of new cartridges, as the degradation of properties during recycling can mean such plastics no longer meet the necessary chemical resistance requirements. Limited options for chemically recycled plastics providing ‘virgin-like’ properties exist, but these come at a cost penalty and / or limitations in the amount of claimed recycled content. Providing a metal cartridge housing alone is not sufficient to ensure that the cartridge as a whole has sufficiently high barrier properties, however, due to the presence of one or more open inlets and outlets in the cartridge. To this end, the cartridge 14 additionally includes a second feature which contributes to the high barrier performance of the cartridge. That feature is at least one removable or breakable high barrier layer 42, 44 sealingly covering the one or more inlets 32 and the one or more outlets 34.

[0066] The high barrier layer(s) operate to seal the inlets and outlets during storage and transport in order to prevent air and moisture ingress to the interior of the cartridge. To this end, the high barrier layer(s) each have a closed perimeter in sealing connection with a surface of the metal cartridge housing, so as to span from and connect to the metal housing in a closed perimeter, covering the inlet and outlet openings and preventing air and / or moisture ingress through those openings. By “sealing connection” it is meant that the seal between the barrier layer(s) and the cartridge housing is sufficient to prevent the transmission of moisture and gas through the interface between the barrier layer and the metal housing (at least at a rate which would negatively impact the shelf-life of the cartridge).

[0067] In addition to covering the one or more inlets and the one or more outlets, the at least one removable or breakable high barrier layer 42, 44 sealingly covers the electrical connections 38. Although they do not form part of the airflow path through the cartridge, the electrical connections 38 nevertheless provide a potential route for air ingress to the interior of the cartridge housing at the point where the electrical connections 38 pass through the lower surface 22c of the housing and / or through the supporting and sealing structure 27. By ensuring the at least one removable or breakable high barrier layer 42, 44 sealingly covers the electrical connections 38, as well as the inlet(s) 32 and the outlet(s) 34, the barrier properties of the cartridge 14 as a whole may be improved.

[0068] The barrier layer material should have high to very-high barrier properties to prevent moisture and gas permeation, with an OTR < 20 cm3 / m2 / 24hr, WVTR < 20g / m2 / 24hr, but preferably OTR < 6 cm3 / m2 / 24hr, WVTR < 6g / m2 / 24hr). Due to the very high barrier properties of the metal housing, the barrier properties of the barrier layers potentially can be relaxed (i.e. the barrier layers need not have an OTR and / or WVTR that is as high as that of the housing), provided the overall barrier properties of the cartridge as a whole are sufficient to meet the shelf-life requirements.

[0069] The high barrier layer(s) can be either, or a combination of, removed prior to connecting the cartridge to the base part by a user or pierceable by the base part or the user to expose or open the air inlet and vapor outlet. Thus the high barrier layer(s) may be peelable, in that the sealing connection is maintained by an impermanent adhesive, or may be frangible, in which case the sealing connection may be achieved in a more permanent manner, such as by welding.

[0070] As shown in Figure 1 , it may be desirable for a first removable or breakable high barrier layer 42 to sealingly cover both the air inlet 32 and the electrical connections 38. This simplifies access to the cartridge for the user when the user requires to connect the cartridge to the base part, as only one high barrier layer need to be removed from the interface surface of the cartrdige.

[0071] Like the housing, the barrier layer material could be a metal, such as aluminium, which inherently has very high barrier properties. However, in the example shown in Figure 1 the barrier layers 42, 44 are comprised of a paper-based material with barrier coatings (e.g. plastics barrier coatings). The barrier layers 42, 44 are both peelable layers, and may be thought of as barrier stickers. An advantage of paper-based stickers (as opposed to aluminium stickers) is that such stickers may provide a visual cue to a user that the sticker should be removed prior to use. This may be indicated by the different material of the stickers, and / or by indicia printed on the stickers. To aid a user in removing the stickers 42, 44, each sticker includes a graspable tab 46, by means of which a user may take hold of the sticker and peel it away from the housing 22 of the cartridge.

[0072] It should be noted that, whilst it is possible to seal off the air inlet and aerosol outlet of a conventional plastics cartridge housing with barrier stickers similar to those described above, this still would not result in sufficient barrier properties to maintain the freshness of the e-liquid over an acceptable shelf life. This is due to the plastics used, largely driven by chemical resistance, manufacturability and cost, only having low to medium barrier OTR and WVTR properties. Thus sealing the inlets and outlets still would not result in a cartridge which overall has sufficient barrier properties at the thicknesses typically used, ranging 0.5mm to 1mm.

[0073] Turning now to Figure 2, five different options are illustrated by means of which a metal cartridge housing may be manufactured. In each of the examples, labelled 2A-2E, the cartridge comprises a substantially cylindrical side wall 22a. In some of the examples (all but example 2D), the cartridge housings also include one or more features that extend to at least partially cover the upper and lower surfaces 22b, 22c of the housing. For clarity, only the metal housing and barrier layer locations are shown in Figure 2, and internal components such as the vapor generation unit 26 and supporting and sealing structure 27 are omitted. In the example shown in Figure 2A, the vapour outlet channel 36 is integrally formed with the side wall 22a and the upper surface 22b in an upper housing portion 14a having generally annular cross-section. A supporting and sealing structure 27 of the type shown in Figure 1 may be introduced into an open lower end 45 of the upper housing portion, in order to define and seal a reservoir chamber (not shown). The supporting and sealing structure (not shown), together with a vaporisation unit (not shown), may be retained in place by a lower housing portion 14b, which includes the lower surface 22c of the cartridge housing and a downwardly extending cylindrical rim 47. The lower housing portion 14b has an external diameter that is substantially the same as the internal diameter of the side wall 22a, such that an outer surface of the rim 47 is closely adjacent to or abutting an interior surface of the side wall 22a when the lower housing portion 14b is introduced into the upper housing portion 14a.

[0074] When more than one metal part is utilised, as in the case of Figure 2A, a sealed connection 48 must be achieved between the metal parts (in this case, upper and lower housing portions 14a, 14b). This could be achieved by various means, including, but not limited to, a compressed silicone seal between the parts, bonding, welding, or a compressed seam similar to that used in beverage cans. In the example shown in Figure 2A, the downwardly extending rim 47 provides an increased surface area for forming such a sealed connection, so improving the ease of manufacture.

[0075] Once the upper and lower housing portions are assembled, enclosing the necessary internal components, then a first barrier layer 42 is secured to the lower surface 22c, covering the air inlet and the electrical connections (not shown), and a second barrier layer is secured to the upper surface 22b, covering the aerosol outlet 34. As discussed above, the barrier layers 42, 44 are in intimate sealing contact with the metal cartridge housing, and in particular with the exterior of the lower surface 22c and of the upper surface 22b.

[0076] Another example cartridge construction, as shown in Figure 2B, comprises a first upper housing portion 14c defined by a cylindrical side wall 22a and a second upper housing portion 14d including an upper surface 22b integrally formed with a vapour outlet channel 36. The second housing portion 14d additionally comprises an upstanding cylindrical rim 49, which may facilitate formation of a sealed connection 48 with the side wall 22a. Once the first and second upper housing portions are joined together using a sealed connection 48 of the type described above, the resulting upper housing portion is similar in structure to that of Figure 2A, and may be assembled with a lower housing portion 14b and first and second barrier layers 42, 44 in a similar manner. The example shown in Figure 2B may be simpler to manufacture than the example of Figure 2A, as the vapour outlet channel 36 is not formed together with the side wall 22a. Further, the structure of Figure 2B opens up the option of forming the vapour outlet channel from a different material to the cartridge housing, such as such as plastic or silicone. In this way the vapour outlet channel could be integrated into the wick and heating system support and sealing structure if required.

[0077] Another alternative example cartridge construction is shown in Figure 2C. This example is similar to that of Figure 2A, but differs in that the lower housing portion 14e comprises an upstanding cylindrical rim 51 which has an internal diameter sized to be slightly larger than the external diameter of the side wall 22a, so that the lower housing portion 14e may be fitted over the open lower end of the upper housing portion 14f, rather than received within it.

[0078] Figure 2D shows a significantly simplified cartridge housing 14g in which the upper and lower surfaces 22b, 22c are omitted. The metal cartridge housing is thus, in this example defined only by a cylindrical side wall 22a. Like the example of Figure 2B, the vapour outlet channel (not shown) may be formed of a non-metal material, and may for example be integrated into the support and sealing structure for the vaporisation unit. Such an arrangement may be easier to manufacture, but lowers the recyclable metal content of the cartridge. In order to maintain a sufficient barrier, the barrier layers 42, 44 may extend completely over the upper and lower ends of the cartridge, so as to form a sealing connection with the side wall 22a. In particular, the first barrier layer 42 is provided in intimate sealing contact with the side wall 22a around an annular perimeter at a first (lower) end of the side wall, whilst the second barrier layer 44 is provided in intimate sealing contact with the side wall 22a around an annular perimeter at a second (upper) end of the side wall.

[0079] Figure 2E shows yet a further example construction that is similar to the construction shown in Figure 2A, with the exception that the vapour outlet channel 36 is formed separately from the upper housing portion 14h. Instead, the upper housing portion includes a generally cylindrical lip or flange 53 extending internally into the housing portion at a central position to facilitate joining the upper housing portion with the vapour outlet channel in a sealed connection 48, for example via one of the methods described above. The lip 53 defines an opening through the upper surface 22b which serves as the outlet 34 once the cartridge is assembled. In all of the examples shown in Figures 2A-2E, the metal housing portions 14a-h and 36 can be manufactured via any appropriate cost-effective method suitable for high-volume production, such as, but not limited to, deep-drawing, stamping, or cold forming. The finished metal housing thickness should be in the range 0.1mm to 0.5mm, and preferably in the range 0.2mm to 0.3mm, to provide sufficient structural rigidity to support the internal contents, to achieve sealing between the internal components and the cartridge housing, and to ensure durability when in use.

[0080] The internal surfaces of the metal housing may be coated with a food-contact grade barrier material that is suitable for use with e-liquids, for example similar to coatings used on beverage cans or aluminium coffee pods.

[0081] It will be understood that the example constructions given above are examples only, and other cartridge housing arrangements are possible. For example, the cartridge housing need not be cylindrical, and may have a different configuration of vapour transfer channel.

[0082] It will be further understood that the barrier layers 42, 44 need not be provided in the locations shown in the examples of Figure 2. For example, separate barrier layers could be provided for the air inlet(s) and electrical connections, if required. Alternatively, barrier layers of the type shown in Figure 2D, which are operable to seal against the side wall of the cartridge housing 22 in order to fully cover the upper and / or lower ends of the cartridge, may be used in conjunction with other housing constructions, such as those shown in Figures 2A-2C and 2E.

[0083] Turning now to Figure 3, four different example options for barrier layer locations are illustrated. In each example, the barrier layers span from and connect to the metal cartridge housing 22 in a closed perimeter, covering any openings into the interior of the housing (e.g. air inlet, vapor outlet, device connection points). As described above, the barrier layers may connect to the side walls of the cartridge, or to the upper and lower surfaces of the cartridge.

[0084] Figure 3A shows an arrangement similar to those shown in Figures 1 and 2, in which an individual first barrier layer 42 is used to cover all non-barrier openings on the lower end of each of a plurality of cartridges 14, whilst an individual second barrier layer 44 is used to cover all non-barrier openings on the upper end of each cartridge 14.

[0085] Figure 3B shows an alternative arrangement in which a first shared high barrier layer 420 sealingly covers the one or more inlets and the one or more electrical connections of each of a plurality of cartridges 14. Similarly, a second shared high barrier layer 440 sealingly covers the one or more outlets of each of the plurality of cartridges. In this way a single barrier layer, such as a peelable sticker, may span over multiple cartridges, which may assist in maintaining the cartridges in a predefined orientation with respect to one another, for example when supported in secondary packaging.

[0086] Figure 3C shows a hybrid arrangement in which a first shared high barrier layer 420 sealingly covers the one or more inlets and the one or more electrical connections of each of a plurality of cartridges 14, whilst each cartridge comprises a respective separate second high barrier layer 44 sealingly covering the one or more outlets of that cartridge. It will be appreciated that the converse arrangement could be employed if required (i.e. a second shared high barrier layer 440 in combination with individual first high barrier layers).

[0087] Figure 3D shows a further alternative arrangement in which each cartridge includes only a single high barrier layer 42a which covers all of the non-barrier openings (inlet(s), outlet(s) and electrical connections) on each cartridge 14. The single barrier layer 42a spans from the lower end of the cartridge, across the side wall 22a of the cartridge, to the upper end of the cartridge. This arrangement has the advantage that the user is only required to remove a single item prior to using the cartridge. Such a barrier layer may include two (or more) sealing perimeters, for example, one which is operable to seal around the outlet and another which is operable to seal around the inlet and electrical connections. Alternatively, a single sealing perimeter may enclose all the non-barrier openings of the cartridge.

[0088] Figure 4 shows packaging 60 which includes a cartridge 14 of the type described above with reference to Figures 1-3 together with a recyclable container 62, such as a cardboard container. The cartridge 14 defines primary packaging for an aerosol generating substrate held in the reservoir chamber 24 of the cartridge, whilst the cardboard container 62 defines secondary packaging for the aerosol generating substrate. The cartridge 14 itself provides high barrier protection for the aerosol generating substrate, and no external plastics packaging is needed. Both the cartridge 14 and the cardboard container 62 may be recycled, and may be manufactured from recycled materials, providing a sustainable packaging solution for the aerosol generating substrate.

[0089] 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.

Claims

CLAIMS1 . A cartridge (14) for an aerosol generating system, the cartridge comprising: a reservoir chamber (24) for holding a liquid aerosol generating substrate; a cartridge housing (22) enclosing the reservoir chamber (24), and having one or more inlets (32) and one or more outlets (34); a vaporising unit (26) including a fluid transfer element and a heating element, the fluid transfer element being in fluid communication with the reservoir chamber (24) and operable to transfer liquid aerosol generating substrate from the reservoir chamber (24) towards a vaporisation area (28), and the heating element being operable to heat liquid aerosol generating substrate present in the vaporisation area (28) to generate an inhalable aerosol; a vapour transfer channel (30) in communication with the vaporisation area (28), the vapour transfer channel (30) connecting the one or more inlets (32) to the one or more outlets (34); and one or more electrical connections (38a, 38b) operable to supply power to the vaporisation unit (26); wherein the cartridge housing (22) is formed from a metal material; and wherein the cartridge comprises at least one removable or breakable high barrier layer (42, 44, 420, 440) sealingly covering the one or more inlets (32), the one or more outlets (34) and the one or more electrical connections (38a, 38b).

2. The cartridge of claim 1 , wherein the at least one removable or breakable high barrier layer (42, 44, 420, 440) has an oxygen transmission rate, OTR, of less than 20 cm3 / m2 / 24hr, and preferably less than 6 cm3 / m2 / 24hr.

3. The cartridge of claim 1 or claim 2, wherein the at least one removable or breakable high barrier layer (42, 44, 420, 440) has a water vapour transmission rate, WVTR, of less than 20 g / m2 / 24hr, and preferably less than 6 g / m2 / 24hr.

4. The cartridge of any of preceding claim, wherein the cartridge housing (22) has an oxygen transmission rate, OTR, of less than 1 cm3 / m2 / 24hr, preferably less than 0.01 cm3 / m2 / 24hr.

5. The cartridge of any of preceding claim, wherein the cartridge housing (22) has a water vapour transmission rate, WVTR, of less than 1 g / m2 / 24hr, preferably less than 0.01 g / m2 / 24hr.

6. The cartridge of any of preceding claim, wherein the cartridge housing (22) is made of aluminium material.

7. The cartridge of any one of any preceding claim, wherein the at least one removable or breakable high barrier layer (42, 44, 420, 440) has a closed perimeter in sealing connection with a surface of the metal cartridge housing (22).

8. The cartridge of any preceding claim, wherein the cartridge comprises a first removable or breakable high barrier layer (42, 420) sealingly covering the one or more inlets (32).

9. The cartridge of claim 8, wherein the first removable or breakable high barrier layer (42, 420) sealingly covers the one or more electrical connections (38a, 38b) as well as the one or more inlets (32).

10. The cartridge of claim 8 or claim 9, further comprising a second removable or breakable high barrier layer (44, 440) sealingly covering the one or more outlets (34).11 . The cartridge of any preceding claim, wherein at least a portion of the vapor transfer channel (30) is formed of a metal material.

12. The cartridge of any preceding claim, wherein the at least one removable or breakable high barrier layer (42, 44, 420, 440) is formed of one of aluminium and paper having a high- barrier coating.

13. Packaging for an aerosol generating substrate, the packaging comprising an outer recyclable cardboard container (62) and the cartridge (14) of any one of claims 1 to 12, wherein the cartridge (14) defines primary packaging for the aerosol generating substrate and the cardboard container (62) defines secondary packaging for the aerosol generating substrate.

14. The packaging of claim 13, wherein the packaging comprises a plurality of cartridges (14) according to any one of claims 1 to 12, and wherein at least two of the plurality of cartridges share a barrier layer (420, 440), such that the shared barrier layer (420, 440) is separately removable from each of the at least two cartridges.

15. The packaging of claim 14, comprising a first shared high barrier layer (420) sealingly covering the one or more inlets (32) and the one or more electrical connections (38a, 38b) ofthe plurality of cartridges (14), and / or a second shared high barrier layer (440) sealingly covering the one or more outlets (34) of the plurality of cartridges.

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