Aerosol generating article

Abstract

An aerosol-generating article for an aerosol-generating device, the article comprising: a first portion containing an aerosol generating substrate, and a second portion downstream of the first portion. The second portion comprises a filter section to filter aerosol passing through the second portion from the first portion. The second portion also comprises a wax structure configured to melt when hot aerosol passes through the second portion thereby cooling the hot aerosol. The wax structure comprises a continuous volume of wax.

Description

[0001] AEROSOL GENERATING ARTICLE

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to aerosol-generating articles for aerosol-generating devices, and in particular heat-not-burn articles.

[0004] BACKGROUND TO THE INVENTION

[0005] A typical aerosol-generating article may include an aerosol-generating substrate and a filter section contained within an external layer of tipping paper. When the article is inserted into an aerosol-generated device, the article is heated until the aerosol-generating substrate generates an aerosol that can be inhaled by the user through the filter section.

[0006] The article normally contains a certain amount of water, which is also vapourised during a session, mainly during the initial few puffs. Since water has a high heat capacity, the water vapour can store a lot of energy, which can be transmitted to the filter section of the article, heating up the filter section as the user inhales. Consequently, this can cause the external tipping paper to heat up too, which may produce an unpleasant sensation on the lips of the user. Furthermore, this may increase the temperature of the inhalable aerosol, which some users may find unpleasant.

[0007] Therefore, it is an object of the present invention to provide an article that can consistently reduce the heating caused by the water vapour, while still maintaining manufacturing simplicity.

[0008] SUMMARY OF THE INVENTION

[0009] According to a first aspect of the present invention there is provided an aerosolgenerating article for an aerosol-generating device, the article comprising: a first portion containing an aerosol generating substrate, and a second portion downstream of the first portion, the second portion comprising a filter section to filter aerosol passing through the second portion from the first portion; wherein the second portion comprises a wax structure configured to melt when hot aerosol passes through the second portion thereby cooling the hot aerosol, the wax structure comprising a continuous volume of wax.

[0010] Advantageously, where water within the article is vapourised during the initial puffs, the wax structure melts thereby absorbing heat from the vapour. The wax structure is thus a phase change material, whereby melting of the wax provides a cooling effect in the article. This improves the user experience, since the user’s lips do not feel any heating of the external surface, and the temperature of the vapour being inhaled is reduced. Since the water vapour is typically produced in the first few puffs, the wax structure is particularly advantageous for increasing the quality and volume of the first puff or the first few puffs.

[0011] By having a continuous volume of wax, the article is also easy to manufacture. For example, a layer of wax may be formed directly upon another component of the article during manufacturing, such as by spraying, rolling or soaking. Alternatively, larger pieces of material such as beads or plugs can be easily assembled together with other components in a small number of steps. The continuous volume can also provide structural reinforcement of the article, such as increasing the rigidity of the second portion. This can make it easier to remove the article from a pack and place it into an aerosol-generating device. The wax structure can also reduce the amount of water that enters the article (e.g., the filter section) during storage and / or transport, which further reduces any negative effects associated with vaporisation of the water. Furthermore, since wax is hydrophobic (water-repelling), any water-soluble impurities in the vapour are trapped by the wax and prevented from reaching the user’s lungs. The wax may also be used to provide a flavourant.

[0012] As used herein the term “continuous volume” preferably connotes a bulk structure of wax. The continuous wax structure may be an uninterrupted structure. The continuous volume of wax may refer to a three-dimensional structure, rather than a substantially two-dimensional layer located within the second portion. Preferably, the wax structure has a thickness greater than 200pm. The article may have a distal end (for insertion into an aerosol-generating device), and a proximal end (from which the user takes a puff). The filter section may comprise tow material. The tow material may be cellulose acetate. The article is preferably a heat-not-burn article for a heat-not-burn device.

[0013] The majority of the wax structure (e.g., more than 50% and preferably more than 80%) may be configured to melt within the first three to five puffs of a session. The majority of the wax structure (e.g., more than 50% and preferably more than 80%) may be configured to melt within the first three minutes of a session. Since the water vapour is typically generated within the first few puffs in the first few minutes of the session, cooling from the wax is not required once this water vapour has been generated and cooled. By limiting the volume of wax to only cooling the first few puffs I for the first few minutes, the mass and / or volume of the article is not increased substantially and ongoing melting of wax does not interfere with desirable vapour compounds in the remainder of the vaping session. Furthermore, using a limited volume of wax means that the wax does not adversely affect vapour generation of desired components with higher boiling points (e.g. , glycerol and propylene glycol). Preferably, the wax structure occupies from about 10% to about 20% of the volume and / or mass of the second portion. Preferably, the wax structure has a total weight between 100mg and 500mg.

[0014] Preferably, the wax structure is continuous over at least 5% of a dimension (e.g., a length or width dimension) of the second portion. The wax structure may be continuous over at least 10%, at least 20%, or at least 50% of a dimension of the second portion. The length dimension may be parallel to a longitudinal axis of the article. The width dimension may be in a direction perpendicular to the longitudinal axis, such as parallel to a radial or circumferential direction.

[0015] Preferably, the wax structure occupies predetermined positions in the second portion. Thus, a set of articles according to the invention may all be substantially identical, where the wax structure occupies the same positions in all of the articles. In this way, the article will have a more consistent response to a user puffing than if the article was manufactured with a randomised wax structure within the second portion.

[0016] Preferably, the wax structure is rotationally symmetrical about a longitudinal axis of the article. In other words, the longitudinal axis may be parallel to the downstream direction. The longitudinal axis extends along the article through both the first portion and the second portion. The rotational symmetry may be discrete rotational symmetry.

[0017] Preferably, the wax structure has continuous rotational symmetry about the longitudinal axis (e.g., structures having circular or ring-shaped cross sections). Alternatively, the wax structure may have discrete rotational symmetry (e.g., structures having triangular, rectangular or other polygonal cross sections). By providing an article with rotational symmetry, the performance of the article is not affected by orientation of the article in an external aerosol-generating device, which provides a more consistent temperature profile and better user experience.

[0018] The wax structure may comprise a wax layer supported within the article on both of its sides. Where the wax structure comprises a wax layer, the term “side” preferably refers to the largest two surfaces of the layer (which may be substantially flat) rather than thin edge surfaces of the layer. The sides are preferably opposing sides of the layer. Advantageously, this ensures that the wax structure remains in a predetermined position throughout storage, transport, and use, thereby ensuring that the article provides more consistent cooling during use. As used herein, the term “supported” preferably indicates that the wax layer directly contacts another component of the article. For example, the wax layer may be sandwiched between two pieces of filter tow. Alternatively, the wax layer may be sandwiched between a piece of paper and a piece of filter tow. Alternatively, the wax layer may be sandwiched between two different portions of the article (e.g., a plug of material with longitudinal sections of material on either side). The wax structure may comprise a wax tube. Advantageously, wax tubes may be easy to manufacture by applying a layer of wax on top of another component of the article. For example, filter tow may be brought through a bath to soak its outside with a wax layer. Alternatively, wax may be applied to a (e.g., cylindrical) surface using rollers or by spraying. Wax tubes may be particularly advantageous in that they can provide longitudinal rigidity to the article.

[0019] The wax tube may be arranged directly beneath an outer paper layer of the article. This arrangement may be particularly easy to construct since the wax layer may be applied to the outer paper layer and then subsequently wrapped around an inner portion (e.g., a filter tow tube), which enables the wax structure to be kept within a more consistent location in the article. Alternatively, the wax layer may be applied to an external surface of the second portion and the outer paper layer may be wrapped on top.

[0020] Alternatively, the wax tube may be arranged between an inner portion (e.g., layer) and an outer portion (e.g., layer) of tow material. Thus, the second portion of the article may include an inner cylinder of tow material (inner portion), a wax tube, and an outer tube of tow material (outer portion). Advantageously, the wax tube occupies a more central location within the article, where both an inner and outer surface of the wax tube may contact the hot vapour to provide a cooling effect. Furthermore, since most of the hot vapour will travel through the inner layer, the outer layer of tow material can act as further insulation to reduce heating of the external surface of the article.

[0021] The wax structure may further comprise a ring of wax upstream of the outer portion of tow material, thereby diverting aerosol through the inner portion of tow material. Advantageously, this provides further wax surfaces for cooling the vapour, and also directs hot vapour to within the wax tube where the vapour can be cooled from all sides. Furthermore, the outer portion of tow material can act as insulation between the vapour and the external (e.g., paper) surface of the article, thereby further reducing the temperature on the user’s lips. The wax structure may comprise a wax layer extending across the cross-section of the article, the wax layer (e.g., substantially) blocking an airflow pathway through the article. Preferably, the wax layer fully blocks the airflow pathway through the article. This maximises the contact between the vapour and the wax, since the vapour cannot reach the user without passing through the wax layer. Therefore, in this configuration, the user is prevented from inhaling hot water vapour. The wax layer may be provided as a solid plug. Alternatively, the wax layer may be manufactured by dipping an end of the filter section into wax.

[0022] The wax structure may comprise one or more beads of wax embedded within the second portion. Advantageously, providing beads in the second portion increases the interaction with the airflow without completely blocking the airflow. This enables cooling of the water vapour without substantially increasing puff resistance. As used herein, the term “bead” preferably refers to a large droplet or capsule of wax. Preferably, the bead may have a spherical shape (e.g., a ball shape) or an ellipsoid shape. Alternatively, the bead may have a prism shape, such as a cylinder. The bead may have a width of at least 10% of the diameter of the article, more preferably at least 25%. The article may include a plurality of beads such as two beads or three beads. The article may include more than three beads.

[0023] The one or more beads of wax may be aligned along a longitudinal axis of the article. In this way, the position of the one or more beads is centred within the article, so that cooling is consistently applied regardless of orientation. Where a plurality of beads is used which align along the longitudinal axis, the vapour may be cooled more gradually over the length of the article, which may reduce condensation of desirable components of the vapour (e.g. , glycerol and propylene glycol). By cooling the vapour more gradually, the article can remove the water without removing the desirable components. Waxes with different melting points may be used for different beads, which may also help to cool the vapour more gradually. The wax beads may be in a granulated form and added to the filter section. Alternatively or additionally, a plurality of beads of wax may be located throughout a cross section of the article (i.e., in a cross sectional direction). The plurality of beads may be located adjacent to each other at substantially the same distance from an end of the article. Advantageously, this may increase the cooling effect applied by the plurality of beads since they more fully block the airflow pathway through the article.

[0024] The beads may be used in both the longitudinal and cross-sectional directions. This may further increase the contact between the beads and the water vapour, during use.

[0025] The second portion may further comprise a tubular cooling section disposed between the filter section and the first portion. The cooling section can be provided by a paper tube and / or a component with a hole through the centre. The cooling section may include ventilation holes to allow external air to flow into the article. By including a cooling section, the distance between the location where vapour is generated and the user’s mouth during use is increased, which further decreases the temperature increase experienced by the user. The article may have more than one cooling section, such as two cooling sections. The cooling section may be configured to absorb moisture. For example, the cooling section may comprise a PLA material, cellulose acetate, polyhydroxyalkanoates (PHA), starch-based bioplastics, chitosan, and / or polycaprolactone (PCL).

[0026] The wax structure may be located in the filter section. Advantageously, the filter plug has a larger surface area than is available within the tubular cooling section, so the same volume of wax can occupy a larger area. By having a larger contact area between the wax and the hot vapour, the vapour can be cooled more effectively. Furthermore, by providing a filter section that can both filter and cool the vapour, a separate cooling section is not necessarily required, and the size of the article may be reduced. Thus, the second portion may include only a filter section and not a tubular cooling section. In addition, by locating the wax structure further from the aerosol generating substrate, the wax only melts when the user takes a puff (rather than melting between puffs due to heat from the heater). Preferably, the wax structure is arranged in the second portion at a position that does not receive heat directly from the heater. The wax structure may be located within a region that is from 15-20 mm from a proximal end of the article.

[0027] Alternatively or additionally, the wax structure may be located in the tubular cooling section. By placing the wax structure in the cooling section, any large droplets of wax can be filtered by the filter portion before being inhaled by the user. Furthermore, since the cooling occurs further upstream in the article, the external surface around the filter section will not warm up as much. This means that the user is less likely to notice an increase in temperature during use.

[0028] The wax structure may comprise a wax and a flavouring component. In this way, the wax structure not only provides cooling of the water vapour but can also be used to enhance the flavour provided to the user.

[0029] The wax structure may be formed from a plurality of waxes with different melting points. For example, a higher melting point wax may be located closer to an upstream end of the article (containing the aerosol generating substrate), and a lower boiling point wax may be located downstream of the article. This allows the water vapour to be cooled more slowly in several stages. Slower cooling may reduce the likelihood of condensation within the article.

[0030] Each wax in the plurality of waxes may have different flavouring properties. For example, some waxes may have no flavouring and other waxes may contain a flavouring component. A tobacco flavoured wax may be used as an outer or downstream part of the structure (e.g., a layer or bead) to provide additional flavour towards the end of a session.

[0031] It will be appreciated that any of the wax structures discussed above can be used in combination with each other in any part of the article. For example, the article may include any number of tubes, beads, rings, or layers arranged in one or both of the filter section and the cooling section.

[0032] According to a second aspect of the present invention there is provided a method of manufacturing an aerosol-generating article, the method comprising: providing a first portion containing an aerosol generating substrate, providing a second portion downstream of the first portion, the second portion comprising a filter section to filter aerosol passing through the second portion from the first portion; and disposing a continuous volume of wax within the second portion to provide a wax structure that is configured to melt when hot aerosol passes through the second portion thereby cooling the hot aerosol.

[0033] The advantages of this aspect correspond to those already discussed above in relation to the first aspect.

[0034] Disposing the continuous volume of wax may include applying a layer of wax directly upon another component of the article (e.g., upon another layer of paper or tow material). The applying may include spraying, rolling or soaking. Alternatively, the disposing may include insertion of a preformed wax structure (e.g., a bead or tube) into the second portion. Alternatively, the disposing may include assembling a piece of wax structure (e.g., a plug or a patch of wax) with other components of the article (e.g., disposing a wax plug between the first portion and second portion, before wrapping in paper).

[0035] It will be understood by a skilled person that any apparatus feature described herein may be provided as a method feature, and vice versa. Moreover, it will be understood that the present invention is described herein purely by way of example, and modifications of detail can be made within the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] One or more embodiments will now be described, purely by way of example, with reference to the accompanying figures, in which:

[0037] Figures 1a to 1c depict a side cross-section, a perspective and a top cross-section view of a typical aerosol generating article;

[0038] Figures 2a to 2c depict a side cross-section, a perspective and a top cross-section view of a first embodiment of an aerosol generating article having a wax structure in a filter section;

[0039] Figures 3a to 3c depict a side cross-section, a perspective and a top cross-section view of a second embodiment of an aerosol generating article having a wax structure in a filter section;

[0040] Figures 4a to 4c depict a side cross-section, a perspective and a top cross-section view of a third embodiment of an aerosol generating article having a wax structure in a filter section;

[0041] Figures 5a to 5c depict a side cross-section, a perspective and a top cross-section view of a fourth embodiment of an aerosol generating article having a wax structure in a filter section;

[0042] Figures 6a to 6c depict a side cross-section, a perspective and a top cross-section view of a fifth embodiment of an aerosol generating article having a wax structure in a filter section;

[0043] Figures 7a to 7c depict a side cross-section, a perspective and a top cross-section view of a sixth embodiment of an aerosol generating article having a wax structure in a filter section;

[0044] Figures 8a to 8c depict a side cross-section, a perspective and a top cross-section view of a comparative example of an aerosol generating article having a wax structure in a filter section, and figure 8d shows an enlarged view of openings in a cooling section of the article;

[0045] Figures 9 to 11 show further aerosol generating articles where a wax structure is instead provided a cooling section; and

[0046] Figures 12 to 14 show further aerosol generating articles where a wax structure is included in both a filter section and a cooling section.

[0047] DETAILED DESCRIPTION

[0048] Figures 1a to 1c show a typical aerosol generating article 100. The article 100 has a substantially cylindrical shape and may be referred to as a heat-not-burn stick 100. The article 100 extends along a longitudinal axis from a distal end 101 to a proximal end 102. During use, the distal end 101 of the article 100 is inserted into an aerosol-generating device (such as a heat-not-burn device), and the user’s mouth receives aerosol from the proximal end 102. An external surface of the article 100 is provided by a piece of tipping paper 105, within which other components of the article 100 are contained.

[0049] More specifically, the article 100 has a first portion 110 and a second portion 120 downstream of (i.e., proximal to) the first portion 110. The first portion 110 contains an aerosol generating substrate 112. The first portion 110 also has an end plug 114 at the distal end 101 of the article 100. The second portion 120 comprises a filter section 130 to filter aerosol passing through the second portion 120 from the first portion 110. The filter section 130 is formed from a cylindrical piece 132 of tow material. The tow material may be cellulose acetate. The second portion 120 also includes a cooling section 140. The cooling section 140 comprises a cooling segment or a cooling tube 142 between the filter section 130 and the first portion 110. The cooling tube 142 has a plurality of ventilation holes or openings 144 around its circumference to allow external air to flow into the article 100 during use. The cooling tube 142 may have other properties, such as helping to absorb water and cool the vapour. For example, the cooling tube 142 may be made from PLA which absorbs water. When the article 100 is inserted into an aerosol-generating device, a heater in the device heats the aerosol generating substrate 112, which causes an inhalable aerosol to be generated in the article 100. When the user draws on from the proximal end 102 of the article 100, the aerosol passes through the filter section 130 and is inhaled by the user.

[0050] However, the aerosol-generating article 100 typically contains a certain amount of water, such as from 10-30 mg. This water is difficult to remove in manufacturing and is also vapourised during use of the article 100. For example, during use of the article 100, 18.1 mg of water may be vapourised by the heater in the device, resulting in 41 J of energy being stored in the water vapour (based on the latent heat of vaporisation of water being 2260 J / g). The vaporisation of the water usually occurs towards the start of a vaporising session, such as within the first 3 minutes or the first five puffs. As the water vapour travels through the article 100, this energy may cause the article 100 to heat up, and in particular may cause heating of the filter section 130 and the tipping paper 105 near the proximal end 102. This can result in an unpleasant sensation on the lips of the user during use. Furthermore, it can be more unpleasant to inhale aerosol that still includes hot water vapour.

[0051] Several examples of aerosol-generating articles 200-900 that address this problem will now be described in relation to Figures 2 to 9. Unless otherwise indicated, these aerosol-generating articles share a number of features with the typical aerosol-generating article 100 already discussed above. For brevity and clarity, the common features have been assigned corresponding reference numerals with matching final two digits. Such common features will not necessarily be described in detail for each and every example, but can be understood with reference to the corresponding description of earlier articles.

[0052] The articles depicted in Figures 2 to 9 all differ from the typical article 100 in that the second portion comprises a wax structure that is configured to melt when hot aerosol passes through the second portion, thereby cooling the hot generated aerosol. The wax structure may comprise a continuous volume of wax. In this way, rather than the energy stored by the hot aerosol being transferred to the article and / or to the user, the wax structure absorbs energy from the hot aerosol by melting. For a substance to undergo a phase change from a solid to a liquid, energy must be absorbed from the surroundings, thereby cooling the surroundings. The amount of energy required to melt a unit mass of the substance is known as the “latent heat of fusion”. A material that is intended to undergo such a phase change may be referred to as a “phase change material” or “PCM”.

[0053] In the example where the article 100 generates 18.1 mg of water vapour, the vaporisation of this water can store a “maximum” of 41 J of energy. However, since most of the water is vapourised in the first few puffs, it is not essential to include enough wax to absorb all of the energy that can be stored by the water vapour. In order to prevent excessive heating of the article it is usually sufficient to have enough wax to cool 60% of the maximum energy. Therefore, in the example where the article generates 18.1 mg of water, the article should contain sufficient wax to absorb a “minimum” of 24.86J of energy.

[0054] The amount of wax required to absorb these minimum and maximum amounts of energy can be calculated based on the latent heat of fusion of the particular wax being used. Waxes suitable for the wax structure are preferably food-grade waxes. The waxes should have a melting point below the boiling point of water (100°C), so that they melt when coming into contact with steam. Suitable waxes may include carnauba wax, candelilla wax, beeswax and paraffin wax. For these types of wax, the table below shows examples of the amounts required to absorb the “minimum” and “maximum” amounts of energy.

[0055] Due to its high latent heat and high density, paraffin wax is particularly advantageous for forming the wax structure since it can absorb the most energy in the smallest volume. This means that the wax structure does not have a significant impact on the size of the article as a whole.

[0056] Figures 2a to 2c shows a first embodiment of an aerosol-generating article 200. The article 200 shares several features with the typical article 100, such as the first portion 210 with aerosol-generating substrate 212 and end plug 214, and a second portion 220 containing a filter section 230 and a cooling section 240. The common features will not be described again in detail.

[0057] The article 200 comprises a wax structure 250 in the form of a continuous volume of wax. More specifically, the wax structure 250 comprises a wax tube 252. The wax tube 252 is located around the cylindrical portion of tow material 232 in the filter section 230. The wax tube 252 is covered by the outer paper layer 205. In other words, the wax tube 252 is supported on both sides by the tow material 232 and the paper 205. The wax tube 252 acts as a thermal break between hot vapour and the outside of the filter section 230, which means the article 200 feels cooler on the lips of the user. The wax structure 250 also removes water vapour from the aerosol and may add wax to the vapour which makes the vapour more pleasurable to inhale.

[0058] The article 200 may be manufactured by coating the paper layer 205 with wax before wrapping the coated paper around the tow material 232. Alternatively, the wax may be applied to the tow material 232 before the paper 205 is wrapped around the article 200. In either case, the wax may be applied by spraying, rolling or soaking. The total volume of the filter section 230 (including the wax) is about 1035 mm3. The volume of the wax structure 250 is about 207 mm3. Thus, the volume of wax structure 250 is about 20% of the total volume of the filter section 230. While the wax tube 252 is depicted here has having a constant thickness, alternatively it may have a variable thickness so as to provide a variable density (e.g., a gradient) of wax along the length of the article 200.

[0059] Figures 3a to 3c shows a second embodiment of an aerosol-generating article 300. The article 300 shares several features with the article 200 described previously, such as the first portion 310 with aerosol-generating substrate 312 and end plug 314, and a second portion 320 containing a filter section 330 and a cooling section 340. The second portion 320 also comprises a wax structure 350 in the form of a wax tube 352. These common features will not be described again in detail.

[0060] The article 300 differs from article 200 in that the wax tube 352 is arranged between an inner portion 332-1 and an outer portion 332-2 of tow material. The inner portion 332-1 may be a cylindrical piece of tow material 332-1 , and the outer portion 332-2 may be a tube of tow material 332-2. Thus, the wax tube 352 is supported on both sides by the tow material 332-1 , 332-2.

[0061] The article 300 may be manufactured by drawing the inner portion 332-1 through a melt bath to cover it in wax. Alternatively, wax may be applied to the inner portion 332-1 by spraying it with wax from a heated nozzle, or by spraying a dissolved solution of the wax in a solvent. Subsequently, the inner portion 332-1 and wax tube 352 are wrapped with the outer portion 332-2.

[0062] Similarly to the article 200, the volume of the filter section 330 (including wax) is about 1035 mm3, and the volume of the wax structure 350 is about 207mm3(about 20% of the total volume).

[0063] Figures 4a to 4c show a third embodiment of an aerosol-generating article 400. This article 400 is identical to the article 300 described in relation to figures 3a to 3c, except in that the wax structure 450 further comprises a wax ring 454 arranged upstream of the outer portion of wax material 432-2. The wax ring 454 diverts hot aerosol through the inner portion 432-1 of tow material, rather than allowing it to flow through the outer portion 432-2 of tow material. This means that the outer portion 432-2 of tow material can act as insulation to reduce heating of the external layer of paper 405.

[0064] Similarly to the articles 200, 300, the volume of the filter section 430 (including wax) is about 1035 mm3, and the volume of the wax structure 450 is about 207mm3(about 20% of the total volume).

[0065] Figures 5a to 5c show a fourth embodiment of an aerosol-generating article 500. The article 500 shares several features with the articles 200-400 described previously, such as the first portion 510 with aerosol-generating substrate 512 and end plug 514, and a second portion 520 containing a filter section 530 and a cooling section 540. The second portion 520 also comprises a wax structure 550. These common features will not be described again in detail.

[0066] However, in the article 500, the wax structure 550 is instead provided by a wax layer 554 extending across the cross-section of the article 500. The wax layer 554 therefore blocks the airflow pathway through the article 500. In this example, the wax layer 554 is located at a distal end of the filter section 530, though in other examples, the wax layer 554 may be located elsewhere. This article 500 advantageously prevents hot aerosol from reaching the proximal end 502 for inhalation without first passing through the wax structure 550, which means that hot vapour is more completely cooled by the wax structure 550.

[0067] The article 500 may be manufactured by applying wax to an upstream end of the filter section 530 prior to the article 500 being assembled with the cooling section 540. The volume of the filter section 530 (including the wax) is about 1035 mm3. The volume of the wax layer 554 is about 103mm3(about 10% of the total volume of the filter section 530).

[0068] Figures 6a to 6c show a fifth embodiment of an aerosol-generating article 600. The article 600 shares several features with the articles 200-500 described previously, such as the first portion 610 with aerosol-generating substrate 612 and end plug 614, and a second portion 620 containing a filter section 630 and a cooling section 640. The second portion 620 also comprises a wax structure 650. These common features will not be described again in detail.

[0069] However, in the article 600, the wax structure 650 is provided as a wax bead 656 embedded within the filter portion 630. The wax bead 656 is in the shape of an ellipsoid with its axis of symmetry aligned along the longitudinal axis of the article 600. In this way, the bead 656 is provided in the airflow pathway of the hot vapour through the article 600 to provide maximum interaction with the airflow but not completely blocking the airflow. The wax bead 656 could be a crushable ball; this may allow the wax to be used at the user’s discretion if they enjoy the extra warmth, prefer to inhale hot water vapour, or would like to use cooling later in a vaping session. The crushable ball may have an outer polymer layer such as polyethylene or polypropylene; this outer layer can be broken to release the wax. The wax may include a flavouring component. The volume of the filter section 630 (including the wax) is about 1035 mm3. The volume of the wax bead 656 is about 103mm3(about 10% of the total volume of the filter section 630).

[0070] Figures 7a to 7c show a sixth embodiment of an aerosol-generating article 700. The article 700 shares several features with the article 600 described previously, such as the first portion 710 with aerosol-generating substrate 712 and end plug 714, and a second portion 720 containing a filter section 730 and a cooling section 740. The second portion 720 also comprises a wax structure 750. These common features will not be described again in detail.

[0071] However, in the article 700 the wax structure 750 is provided by a plurality of wax beads, labelled 756-1. 756-2, 756-3. Each of the beads 756 are substantially spherical and are embedded in the filter portion 730 along the longitudinal axis of the article 700. The volume of the filter section 730 (including the wax beads 756) is about 1035 mm3. The volume of each wax bead 756 is about 34mm3to provide a total volume of wax of about 103mm3(about 10% of the total volume of the filter section 730). Figures 8a to 8d show a comparative example of an aerosol-generating article 800. The article 800 shares several features with the articles 200-700 described previously, such as the first portion 810 with aerosol-generating substrate 812 and end plug 814, and a second portion 820 containing a filter section 830 and a cooling section 840. The second portion 820 also comprises a wax structure 850. These common features will not be described again in detail.

[0072] However, this article 800 differs in that the wax structure 850 does not comprise a continuous volume of wax. Instead, wax is distributed throughout the filter section 830. This may be achieved by soaking the filter section 830 in a wax with a low viscosity and / or increasing the time that the filter section 830 is soaked in the wax; this means that the wax can spread evenly throughout the filter section 830. This arrangement is advantageous since it can allow for more consistent airflow through the filter with a high contact area of the vapour with the wax. However, it may take longer to manufacture (increased soaking time) and may limit which waxes can be used. The volume of the filter section 830 is approximately 1035mm3, and the wax occupies approximately 20% of this volume.

[0073] While in the embodiments above, the wax structure is located in the filter section, it will be appreciated that the wax structure may instead be located in the cooling section. Figures 9 to 11 show three aerosol-generating articles 900, 1000, 1100 where the wax structure is located in only the cooling section. Unless otherwise stated, these articles share features with the articles 200-800 already described.

[0074] In the embodiment shown in Figure 9, the article 900 the wax structure 950 is a wax tube 952 located inside the cooling tube 942 of the cooling section 940. The wax tube 952 may have a volume of about 201 mm3.

[0075] In the embodiment shown in Figure 10, the wax structure 1050 is a plurality of wax beads 1056 disposed inside the cooling tube 1042. Each of the three wax beads 1056 may have a volume of about 53 mm3, so the total volume of the wax structure 1050 is about 159 mm3. In the comparative example shown in Figure 11 , the wax structure 1150 is provided by distributing wax evenly through the cooling tube 1142. The wax may occupy about 40% of the volume of the cooling tube 1042 (equivalent to a volume of 135 mm3of wax).

[0076] While in the embodiments above, the wax structure is located in either the filter section or the cooling section, it will be appreciated that the wax structure may be located in both the filter section and the cooling section. Figures 12 to 14 show three aerosol-generating articles 1200, 1300, 1400 where the wax structure is located in both the filter section and the cooling section. Unless otherwise stated, these articles share features with the articles 200-1100 already described.

[0077] In the embodiment shown in Figure 12, the wax structure 1250 includes a first wax tube 1252-1 in the filter section 1230 and a second wax tube 1252-2 in the cooling section 1240. The first wax tube 1252-1 is located between a first (inner) portion of tow material 1232-1 and a second (outer) portion of tow material 1232-2 (similarly to article 300). The second wax tube 1252-2 is located inside the cooling tube 1242 (similarly to article 900).

[0078] In the comparative example shown in Figure 13, the wax structure 1350 includes wax distributed evenly throughout both the tow material 1332 of the filter section 1330 (similarly to article 800) and the cooling tube 1342 of the cooling section 1340 (similarly to article 1100).

[0079] In the embodiment shown in Figure 14, the wax structure 1450 includes a wax bead 1454 in the filter section 1430 (similarly to article 600) and a wax tube 1452 in the cooling section 1440 (similarly to article 900).

[0080] While Figures 12 to 14 show three possible combinations of wax structures in the filter section and the cooling section, it will be appreciated that any of the wax structures described above can be used in any of the cooling sections or filter sections. In particular, tubes, beads, layers, rings, or distributed wax can be used or combined in one or both of the filter section and the cooling section. Where the wax structure includes more than one continuous volume of wax (e.g., different tubes, beads, layers, and / or rings), the waxes may have different melting points. For example, in the articles 700, 1000, the beads 756-3, 1056-3 that are closer to the distal end 701 , 1001 may have a higher melting point than the beads 756-1 , 1056-1 closer to the proximal end 702, 1002. This allows the hot vapour to be cooled more gradually, which reduces the likelihood of condensation within the articles 700, 1000. Likewise, in the article 1200, the first wax tube 1252-1 may have a lower melting point than the second wax tube 1252-2.

[0081] Furthermore, in any of the articles 200-1400 above, the wax structure may include flavouring. When the wax structure is heated, the flavouring may be released throughout the session. Where the wax structure includes more than one continuous volume of wax (e.g., different tubes, beads, layers, and / or rings), the waxes may have different flavourings. For example, an outer or downstream layer may include tobacco flavouring to provide additional flavour towards the end of the session.

[0082] While the foregoing is directed to exemplary embodiments of the present invention, it will be understood that the present invention is described herein purely by way of example, and modifications of detail can be made within the scope of the invention. Moreover, other and further embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and may be devised without departing from the basic scope thereof, which is determined by the claims that follow.

Claims

CLAIMS1 . An aerosol-generating article for an aerosol-generating device, the article comprising: a first portion containing an aerosol generating substrate, and a second portion downstream of the first portion, the second portion comprising a filter section to filter aerosol passing through the second portion from the first portion; wherein the second portion comprises a wax structure configured to melt when hot aerosol passes through the second portion thereby cooling the hot aerosol, the wax structure comprising a continuous volume of wax.

2. The aerosol-generating consumable article of claim 1 , wherein the wax structure is continuous over at least 5% of a dimension of the second portion.

3. The aerosol-generating consumable article of claim 1 or claim 2, wherein the wax structure comprises a wax layer supported within the article on both of its sides.

4. The aerosol-generating consumable article of any preceding claim, wherein the wax structure comprises a wax tube.

5. The aerosol-generating consumable article of claim 4, wherein the wax tube is arranged directly beneath an outer paper layer of the article.

6. The aerosol-generating consumable article of claim 4, wherein the wax tube is arranged between an inner portion and an outer portion of tow material.

7. The aerosol-generating consumable article of claim 6, wherein the wax structure further comprises a ring of wax upstream of the outer portion of tow material, thereby diverting aerosol through the inner portion of tow material.

8. The aerosol-generating consumable article of any preceding claim, wherein the wax structure comprises a wax layer extending across the crosssection of the article, thereby blocking an airflow pathway through the article.

9. The aerosol-generating consumable article of any preceding claim, wherein the wax structure comprises one or more beads of wax embedded within the second portion.

10. The aerosol-generating consumable article of claim 9, wherein the one or more beads of wax are aligned along a longitudinal axis of the article.

11. The aerosol-generating consumable article of any preceding claim, wherein the second portion further comprises a tubular cooling section disposed between the filter section and the first portion.

12. The aerosol-generating consumable article of any preceding claim, wherein the wax structure is located in the filter section.

13. The aerosol-generating consumable article of any preceding claim, wherein the wax structure comprises a wax and a flavouring component.

14. The aerosol-generating consumable article of any preceding claim, wherein the wax structure is formed from a plurality of waxes with different melting points.

15. A method of manufacturing an aerosol-generating article, the method comprising: providing a first portion containing an aerosol generating substrate, and providing a second portion downstream of the first portion, the second portion comprising a filter section to filter aerosol passing through the second portion from the first portion; anddisposing a continuous volume of wax within the second portion to provide a wax structure that is configured to melt when hot aerosol passes through the second portion thereby cooling the hot aerosol.

Images