Filter for Smoking Article

Abstract

A filter for a vapour generating article includes a filter body having: a first end arranged as a mouthpiece; a second end opposite the first end arranged for attachment to a vapour generating article; the filter further including a cavity located within the filter body between the first and second ends, the cavity configured to allow a fluid including water to flow through the filter body from the second end to the first end; wherein the cavity includes a filter portion arranged to filter the fluid as it flows through the filter body; and wherein the filter portion is arranged to remove at least some of the water from the fluid as it flows through the filter body.

Description

FIELD OF INVENTION

The present disclosure relates to aerosol generating articles for use in an aerosol generation system in which an aerosol generating substrate is heated to form an aerosol. The disclosure is particularly applicable to a portable aerosol generation device, which may be self-contained and low temperature. Such devices may heat, rather than burn, tobacco or other suitable aerosol substrate materials by conduction, convection, and/or radiation, to generate an aerosol for inhalation.

BACKGROUND

The popularity and use of reduced-risk or modified-risk devices (also known as vaporisers) has grown rapidly in the past few years as an aid to assist habitual smokers wishing to quit smoking traditional tobacco products such as cigarettes, cigars, cigarillos, and rolling tobacco. Various devices and systems are available that heat or warm aerosolisable substances as opposed to burning tobacco in conventional tobacco products.

A commonly available reduced-risk or modified-risk device is the heated substrate aerosol generation device or heat-not-burn device. Devices of this type generate an aerosol or vapour by heating an aerosol substrate that typically comprises moist leaf tobacco or other suitable aerosolisable material to a temperature typically in the range 150° C. to 350° C. Heating an aerosol substrate, but not combusting or burning it, releases an aerosol that comprises the components sought by the user but not the by-products of combustion and burning.

In such devices, the aerosol substrate is typically included in a consumable that is held within a heating chamber and heated by a heater. The consumable contains a quantity of aerosol generating substrate and is able to generate a quantity of aerosol.

Due to the portable nature of the aerosol generating device, the environmental conditions in which the user uses the device may vary. This has the effect that the aerosol substrate within the consumable takes on different amounts of moisture depending on the humidity of the surrounding environment in which the device is being used, as well as on how long the consumable has been exposed to the air after a packet of consumables has been opened but the user for insertion into the device.

Humidity in the generated aerosol is undesirable because its relatively high specific heat capacity would result in a hot aerosol, which is uncomfortable and potentially dangerous to inhale by the user.

The present invention aims to provide a device in which the humidity of the aerosol is reduced.

SUMMARY

According to a first aspect there is provided a filter for a vapour generating article comprising a filter body, the filter body comprising a first end arranged as a mouthpiece and a second end opposite the first end arranged for attachment to a vapour generating article. The filter further comprises a cavity located within the filter body between the first and second ends. The cavity is configured to allow a fluid comprising water to flow through the filter body from the second end to the first end. The cavity comprises a filter portion arranged to filter the fluid as it flows through the filter body. The filter portion is arranged to remove at least some of the water from the fluid as it flows through the filter body.

In some developments, the filter portion may be arranged to remove substantially all of the water from the fluid.

Since vapour generating articles are used in a variety of locations, due to their portability, the environmental conditions experienced by the filter cannot be controlled as so the level of moisture experienced by the filter, and absorbed by the filter, vary depending upon the humidity of the surrounding environment and how long the filter has been exposed to this environment. High humidity causes hot vapour which is undesirable for the user. As it is not possible to control the humidity entering the filter from the environment, the present filter removes the humidity from the vapour using the filter portion. The filter therefore provides effective filtering which removes water from the vapour as it flows through the filter, improving the overall user experience.

In some examples, the filter portion comprises a selective filter medium arranged to selectively filter water from the fluid. Providing a selective filter medium which is arranged to selectively filter water from the fluid helps ensure that more water is removed from the vapour, because other components within the fluid are allowed to pass through the filter rather than being removed by the filter in addition to the water.

Preferably, the selective filter medium comprises a water-absorbing medium. The water-absorbing medium helps remove more water from the fluid as it passes through the filter portion. Removing more water from the fluid which in this case is the generated vapour, reduces the humidity of the generated vapour. This in turn provides a cooler vapour for the user to inhale giving a more pleasant user experience during use.

The water-absorbing medium may comprise any suitable selective water absorbing material for example silica, at least one molecular sieve, or at least one hydrophilic sponge material. These may be used alone or in combination with each other. Of course, any other suitable water-absorbing material could be used either alone or in combination with any other water-absorbing material.

Preferably, the second end of the filter is releasably attachable to a vapour generating article. The filter may therefore be attached for a vapour generating article when the user desires to use the article, and removed from the article when the user has consumed the substrate within the article. In this way, the filter is a re-usable filter and can be used with multiple vapour generating articles.

Typically vapour generating devices comprise a consumable article housing the substrate and a filter attached to the consumable. Once the substrate has been consumed by the user, the vapour generating device is disposed of because the consumable article is no longer usable. Since the filter is attached to the consumable article, the filter is also disposed of at the same time. As a result, filters typically comprise simple technology which is not expensive to throw away.

By providing a filter that can be releasably attached to a vapour generating article (also referred to as a consumable article), the filter can be re-used with a subsequent vapour generating article instead of being disposed of each time. For example the filter may be able to be used 20-100 times, and so the filter can be used with 20-100 different vapour generating articles, before the filter needs to be changed and disposed of.

This has the effect that more complex and expensive technology can be used within the filter, in particular more efficient and more effective filtering technology can be employed within the filter. As an illustration, using a re-usable filter which only needs to be changed after every 20-100 vapour generating articles means that the technology within the filter can be 20-100 times the cost of a single-use disposable filter. Thus, having a filter in which the second end of the filter is releasably attachable to a vapour generating article provides a re-usable filter including a selective filter medium to efficiently and effectively remove water from the vapour. Advantageously, the filter may comprise technology which are able to remove water from the vapour using technologies that have previously been non-viable due to cost.

According to another aspect there is provided a vapour generating article comprising a first end arranged for connection with a vapour generating device, and a filter wherein the filter is attached to a second end of the vapour generating article. The filter is a filter according to any of the above described filters.

According to another aspect there is provided a vapour generating system comprising a filter according to any of the above described filters, a vapour generating article according to the above described vapour generating article, and a vapour generating device configured to receive the vapour generating article.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the present invention will be now described by way of example only with reference to the accompanying drawing in which:

FIG. 1 shows an example aerosol generating article.

DETAILED DESCRIPTION

Referring to FIG. 1 an example aerosol generating article 1, in the form of an elongate consumable 1, is shown located within an aerosol generating device 2 in order to generate an aerosol.

The aerosol generating article 1 comprises a rod-shaped portion 11, and a filter 14.

The rod-shaped portion 11 comprises aerosol generating substrate 12 that extends over a portion of the length of the rod-shaped portion 11. The aerosol generating substrate 12 is arranged at an end of the aerosol generating article 1 that is within a heating chamber of the aerosol generating device 2 and furthest from an opening of the heating chamber. The aerosol generating substrate 12 is a material which, when heated, generates an aerosol. The aerosol generating substrate 12 may, for example, comprise tobacco or nicotine. The aerosol is drawn out of the aerosol generating article 1 by air flow through the filter 14.

The aerosol generating device 2 comprises a heating chamber 21 and a heater 22.

The heating chamber 21 is a tubular structure with an internal hollow in which the aerosol generating article 1, or the rod-shaped portion 11 of the aerosol generating article 1, may be received. Specifically, the heating chamber comprises a side wall extending between a first end 212 and a second end 213. The first end 212 is open, or openable in use, in order to allow the rod-shaped portion 11 to be inserted. The second end 213 may be open as shown in FIG. 1A, in order to provide an air inlet for air to flow through the aerosol generating article. Alternatively, the second end 213 may be closed in order to improve heating efficiency of the heating chamber 21.

The heating chamber 21 may be formed from ceramic or metal. For example, the heating chamber 21 may be formed by bending or stamping sheet metal. The heater 22 may be any heater suitable to deliver heat into the internal hollow of the heating chamber 21 through its side wall. For example, the heater may be in the form of a resistive track driven by electricity. Alternatively, other types of heater may be used such as ones in which heat is provided by a chemical reaction such as fuel combustion. The heating chamber may further be surrounded by a heat insulator such as a vacuum tube, heat insulation fibre and/or aerogel.

In use, the heater 22 is arranged to heat the heating chamber 21 to a temperature sufficient to cause the aerosol generating substrate 12 to release an aerosol, without burning the aerosol generating article 1. In particular, the heater 22 is configured to heat the aerosol generating substrate 12 to a maximum temperature between 150° C. and 350° C., more preferably to a temperature between 200° C. and 350° C.

Although the heater 22 is shown outside the heating chamber 21 in FIG. 1A, the heater 22 may in some embodiments be arranged inside the heating chamber 21.

The aerosol generating article 1 further comprises an aerosol cooling region 15. The aerosol cooling region 15 extends over a portion of the length of the aerosol generating article 1 and comprises a hollow tubular portion of the aerosol generating article 1. This hollow tubular portion allows an aerosol (generated by heating the aerosol generating substrate 12) to pass through the aerosol generating article 1 without leaking through the sides of the hollow tubular portion. The aerosol cooling region 15 does not overlap with the part of the aerosol generating article 1 that is being heated by the heater 22, which may be referred to as a heating region, so aerosol will not continue to be heated within the aerosol cooling region 15.

As mentioned, the aerosol substrate 15 is arranged at the end of the aerosol generating article 1 that is within the heating chamber 21 and furthest from the opening 212. The filter 14 is arranged at the other end that is closest to the opening 212. The aerosol cooling region 15 extends along the length of the aerosol generating article 1 between the aerosol generating substrate 12 and the filter 14. This ensures that, in use, a generated aerosol may be cooled before inhalation by a user.

Further details of the filter 14 will now be described.

The filter 14 comprises a filter body 114 having a first end 102 in the form of a mouthpiece and a second end 104, opposite the first end 102, for attaching to the rod-shaped portion 11 of the aerosol generating article 1. The filter 14 further comprises a cavity 106 which is located within the filter body 114 between the first and second ends. The cavity 106 allows a fluid, comprising water, to flow through the filter body 114 from the second end 104 to the first end 102. The cavity 106 comprises a filter portion 108 which filters the fluid as it flows through the filter body 114. In particular, the filter portion 108 removes at least some of the water from the fluid as it flows through the filter body 114. It should be noted that the fluid in this context refers to the aerosol or vapour that has been generated by the aerosol generating article 1.

The filter 14 is typically made of any suitable plastic material, and the aerosol generating article 1 is typically made from paper.

In order to more efficiently remove water from the vapour as it passes through the filter body 114, the filter portion comprises a selective water absorbing media which selectively absorbs water from the fluid, in preference over other liquids within the fluid. Any suitable selective water absorbing media can be used for example silica, molecular sieves, or hydrophilic sponge materials.

In use, when the user draws on the mouthpiece end 102 of the filter and vapour is inhaled through the filter 14, the selective water-absorbing media removes water from the vapour to be inhaled, which reduces the humidity of the inhaled vapour. Since water has a relatively high specific heat capacity, a vapour with a high humidity can be very hot which can be dangerous and unpleasant for the user to inhale. Thus, reducing the humidity within the filter helps lower the temperature of the inhaled vapour which provides a safer aerosol generating article 1, as well as improves the overall sensory experience for the user.

The filter 14 is re-usable filter 14 because it can be detached from one rod-shaped portion 11 of a first aerosol generating article 1, at the second end 104, and the re-attached to another rod-shaped portion 11 of a second aerosol generating article 1 via the second end 104. In particular, the filter 14 may slot into or onto the rod-shaped portion 11 using any suitable temporary attachment mechanism. The filter 14 can therefore be considered as being releasably attachable and able to be used with multiple aerosol generating articles. In other words, the filter 14 can be said to be semi-disposable.

Thus, when the filter 14 is attached to the rod-shaped portion 11, a vapour generating article 1 is formed. In particular, the vapour generating article 1 includes a first end and a second end, and the filter 14 attaches to the second end of the vapour generating article 1. The first end of the vapour generating article 1 may be used to connect with a vapour generating device 2. In this case, a vapour generating system is formed comprising the a vapour generating article 1 and the vapour generating device 2 which receives the vapour generating article 1.

It should be understood that the aerosol generation device is an electronic cigarette which could equally be referred to as a “heated tobacco device”, a “heat-not-burn tobacco device”, a “device for vaporising tobacco products”, and the like, with this being interpreted as a device suitable for achieving these effects. The features disclosed herein are equally applicable to devices which are designed to vaporise any aerosol generating medium.

The aerosol generating substrate 12 may include tobacco, for example in dried or cured form, in some cases with additional ingredients for flavouring or producing a smoother or otherwise more pleasurable experience. In some examples, the aerosol generating substrate 12 such as tobacco may be treated with a vaporising agent. The vaporing agent may improve the generation of vapour from the aerosol generating substrate 12. The vaporising agent may include, for example, a polyol such as glycerol, or a glycol such as propylene glycol. In some cases, the aerosol generating substrate 12 may contain no tobacco, or even no nicotine, but instead may contain naturally or artificially derived ingredients for flavouring, volatilisation, improving smoothness, and/or providing other pleasurable effects.

The aerosol generating substrate 12 may be provided as a solid or paste type material in shredded, pelletised, powdered, granulated, strip or sheet form, optionally a combination of these. Equally, the aerosol generating substrate 12 may be a liquid or gel. Indeed, some examples may include both solid and liquid/gel parts. Indeed, some examples may include both solid and liquid/gel parts. In some examples, the substrate 12 may be a solid block, or may be loose material packed in a wrapper 13. Preferably the substrate comprises randomly oriented tobacco strands containing tobacco powder and an aerosol former. Suitable aerosol formers include: a polyol such as sorbitol, glycerol, and glycols like propylene glycol or triethylene glycol; a non-polyol such as monohydric alcohols, acids such as lactic acid, glycerol derivatives, esters such as triacetin, triethylene glycol diacetate, triethyl citrate, glycerin or vegetable glycerin. In some embodiments, the aerosol generating agent may be glycerol, propylene glycol, or a mixture of glycerol and propylene glycol.

Whilst the aerosol generating substrate 12 will typically produce a gas or a solid and/or liquid suspension in gas when heated, it will be appreciated that the terms ‘vapour’ and ‘aerosol’ are generally used interchangeably here, and refer generally to the substance which is produced when the aerosol generating substrate 12 is heated, to produce a suspension of particles or droplets of any size.

As used herein, the term “fluid” shall be construed as generically describing non-solid materials of the type that are capable of flowing, including, but not limited to, liquids, pastes, gels, powders and the like. “Fluidized materials” shall be construed accordingly as materials which are inherently, or have been modified to behave as, fluids. Fluidization may include, but is not limited to, powdering, dissolving in a solvent, gelling, thickening, thinning and the like.

Claims

1. A filter for a vapour generating article comprising:

a filter body comprising: a first end arranged as a mouthpiece; and a second end opposite the first end arranged for attachment to a vapour generating article; and

a cavity located within the filter body between the first and second ends, the cavity configured to allow a fluid comprising water to flow through the filter body from the second end to the first end;

wherein the cavity comprises a filter portion arranged to filter the fluid as the fluid flows through the filter body; and

wherein the filter portion is arranged to remove at least some of the water from the fluid as the fluid flows through the filter body.

2. The filter of claim 1, wherein the filter portion comprises a selective filter medium arranged to selectively filter water from the fluid.

3. The filter of claim 2, wherein the selective filter medium comprises a water-absorbing medium.

4. The filter of claim 3, wherein the water-absorbing medium comprises silica.

5. The filter of claim 3, wherein the water-absorbing medium comprises a molecular sieve.

6. The filter of claim 3, wherein the water-absorbing medium comprises a hydrophilic sponge material.

7. The filter according to claim 1, wherein the second end of the filter is releasably attachable to a vapour generating article.

8. A vapour generating article comprising:

a first end arranged for connection with a vapour generating device;

a filter according to claim 1, wherein the filter is attached to a second end of the vapour generating article.

9. A vapour generating system comprising:

a filter according to claim 1;

a vapour generating article comprising a first end arranged for connection with a vapour generating device, wherein the filter is attached to a second end of the vapour generating article; and

a vapour generating device configured to receive the vapour generating article.