Smoking substitute consumable

Abstract

The present disclosure relates to smoking substitute consumables, including an aerosol-forming article comprising an aerosol-forming substrate and a terminal filter element at a downstream axial end of the article/consumable. The terminal filter element may comprise a hollow bore extending from an upstream axial end of the terminal filter element to a downstream axial end of the terminal filter element. The hollow bore may be off-set from the axial centre of the terminal filter element.

1 . An aerosol-forming article comprising an aerosol-forming substrate and a terminal filter element at a downstream axial end of the article/consumable wherein the terminal filter element comprises a hollow bore extending from an upstream axial end of the terminal filter element to a downstream axial end of the terminal filter element wherein the hollow bore is off-set from the axial centre of the terminal filter element. 
     
     
         2 . An article according to  claim 1 , wherein the aerosol-forming article is a heat-not-burn (HNB) consumable. 
     
     
         3 . An article according to  claim 1 , further comprising an upstream filter element provided upstream of the terminal filter element. 
     
     
         4 . An article according to  claim 3  wherein the upstream filter element is a hollow bore filter element comprising an axial bore. 
     
     
         5 . An article according to  claim 3 , wherein the diameter of the axial bore in the upstream filter element is greater than the diameter of the offset bore in the terminal filter element. 
     
     
         6 . An article according to  claim 3 , wherein the porosity of the upstream filter element is less than the porosity of the terminal filter element. 
     
     
         7 . An article according to  claim 3 , wherein the upstream and terminal filter elements are spaced apart by a cooing element and/or a spacer element. 
     
     
         8 . A system comprising:
 a smoking substitute article having a downstream axial end, the smoking substitute article comprising:
 an aerosol-forming substrate; and 
 a terminal filter element having an upstream axial end and a downstream axial end, and a hollow bore extending from the upstream axial end of the terminal filter element to the downstream axial end of the terminal filter element, wherein the hollow bore is off-set from an axial centre of the terminal filter element; and 
   a device comprising a heating element.   
     
     
         9 . A system according to  claim 8 , wherein the device comprises a main body for housing the heating element and the heating element comprises an elongated heating element. 
     
     
         10 . A method of using the system according to  claim 8 , the method comprising:
 inserting the article into the device; and   heating the article using the heating element.   
     
     
         11 . A method according to  claim 10 , comprising inserting the article into a cavity within a main body of the device and penetrating the article with the heating element upon insertion of the article. 
     
     
         12 . A Heat-Not-Burn (HNB) consumable comprising an aerosol-forming substrate and a flow restrictor element downstream of the aerosol-forming substrate. 
     
     
         13 . A HNB consumable according to  claim 12 , further comprising in axial flow arrangement, an upstream filter element, a spacer element, and a terminal filter element, wherein at least one of the filter elements is a hollow bore filter element and wherein the flow restrictor element is provided upstream of the terminal filter element and downstream of the aerosol-forming substrate. 
     
     
         14 . An aerosol-forming article comprising, in axial flow arrangement, an aerosol-forming substrate, an upstream filter element, a spacer element and a terminal filter element, wherein at least one of the filter elements is a hollow bore filter element and wherein the article further comprises a flow restrictor element upstream of the terminal filter element and downstream of the aerosol-forming substrate. 
     
     
         15 . A consumable/article according to  claim 14  wherein the flow restrictor element comprises a disc or rod having at least one axial perforation or channel. 
     
     
         16 . A consumable/article according to  claim 15  wherein the flow restrictor element has a single perforation or channel at its axial centre having a diameter of between 0.5 and 1.5 mm. 
     
     
         17 . A consumable/article according to  claim 14  wherein the flow restrictor element is formed of a vapour-impermeable material. 
     
     
         18 . A consumable/article according to  claim 14  wherein the flow restrictor element is formed of extruded tobacco. 
     
     
         19 . A consumable/article according to  claim 14  wherein the flow restrictor element is provided upstream of the spacer element. 
     
     
         20 . A consumable/article according to  claim 19  wherein the restrictor element is interposed between the upstream filter element and the spacer element. 
     
     
         21 . A consumable/article according to  claim 14  wherein the upstream filter element is a hollow bore filter having a bore diameter greater than 1.5 mm. 
     
     
         22 . A consumable/article according to  claim 14  wherein both the upstream and terminal filter element are hollow bore filter elements. 
     
     
         23 . A system comprising:
 a HNB consumable or smoking substitute article comprising, in axial flow arrangement:
 an aerosol-forming substrate, 
 a flow restrictor element downstream of the aerosol-forming substrate; 
 an upstream filter element, 
 a spacer element; and 
 a terminal filter element downstream of the flow restrictor element and downstream of the aerosol-forming substrate, 
 wherein at least one of the upstream filter element and the terminal filter element is a hollow bore filter element; and 
   a device comprising a heating element.   
     
     
         24 . A system according to  claim 23  wherein the device comprises a main body for housing the heating element and the heating element comprises an elongated heating element. 
     
     
         25 . A method of using the system according to  claim 23 , the method comprising:
 inserting the consumable/article into the device; and   heating the consumable/article using the heating element.   
     
     
         26 . A method according to  claim 25 , further comprising inserting the consumable/article into a cavity within a main body of the device and penetrating the consumable/article with the heating element upon insertion of the consumable/article. 
     
     
         27 . An aerosol-forming article comprising a cooling element comprising a phase change material. 
     
     
         28 . An article according to  claim 27 , wherein the article is a heat not burn (HNB) consumable. 
     
     
         29 . An article according to  claim 27 , wherein the phase change material is an organic phase change material. 
     
     
         30 . An article according to  claim 29 , wherein the phase change material is eicosane. 
     
     
         31 . An article according to  claim 27 , wherein the cooling element comprises a plurality of phase change beads each comprising a shell enclosing a core formed of the phase change material. 
     
     
         32 . An article according to  claim 27 , wherein the cooling element comprises a cylindrical body and the phase change material/beads are dispersed within the body. 
     
     
         33 . An article according to  claim 32 , wherein the cylindrical body comprises an axial bore extending therethrough. 
     
     
         34 . An article according to  claim 32 , wherein the cylindrical body comprises a matrix of fibrous, granular, sheet or solid plastics material. 
     
     
         35 . An article according to  claim 34 , wherein the plastics material comprises one or more of viscose, cellulose, polyester, polyacrylonitrile, polylactic acid, polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). 
     
     
         36 . An article according to  claim 35 , wherein the fibrous plastics material is selected from viscose, cellulose, polyester, acrylic or polylactic acid fibres. 
     
     
         37 . An article according to  claim 27 , wherein the cooling element is formed of Outlast® viscose fibres. 
     
     
         38 . An article according to  claim 27 , wherein the cooling element is sandwiched between a terminal filter element and an upstream filter element downstream of an aerosol-forming substrate. 
     
     
         39 . A system comprising a smoking substitute article according to  claim 27  and a device comprising a heating element. 
     
     
         40 . A system according to  claim 39 , wherein the device comprises a main body for housing the heating element and the heating element comprises an elongated heating element. 
     
     
         41 . A method of using the system according to  claim 39 , the method comprising: inserting the article into the device; and heating the article using the heating element. 
     
     
         42 . A method according to  claim 41 , comprising inserting the article into a cavity within a main body of the device and penetrating the article with the heating element upon insertion of the article. 
     
     
         43 . An aerosol-forming article comprising an aerosol-forming substrate wherein the article further comprises: a terminal filter element at the axial downstream of end of the article, the terminal filter element being a hollow bore filter element; and one or more of an upstream filter element, an upstream aerosol-cooling element and an upstream spacer element. 
     
     
         44 . An article according to  claim 43 , wherein the internal diameter of the bore in the terminal filter element is between 1 and 3 mm. 
     
     
         45 . An article according to  claim 43 , comprising the upstream filter element wherein the upstream filter element is a hollow bore filter element. 
     
     
         46 . An article according to  claim 45 , wherein the internal diameter of the bore in the upstream filter element is greater than the internal diameter of the bore in the terminal filter element. 
     
     
         47 . An article according to  claim 45 , wherein the density of the filter material forming the terminal filter element is greater than the density of the filter material forming the upstream filter element. 
     
     
         48 . An article according to  claim 45 , wherein the upstream filter element and terminal filter element are axially spaced. 
     
     
         49 . An article according to  claim 48 , further comprising the aerosol-cooling element wherein the upstream filter element and terminal filter element are spaced by the aerosol-cooling element. 
     
     
         50 . An article according to  claim 48 , further comprising the spacer element wherein the upstream filter element and terminal filter element are spaced by the spacer element. 
     
     
         51 . An article according to  claim 45 , wherein the spacer element is a cardboard tube. 
     
     
         52 . An article according to  claim 45 , wherein the aerosol-cooling element comprises a crimped/gathered sheet of plastics material. 
     
     
         53 . A system comprising a smoking substitute article according to  claim 45 , and a device comprising a heating element. 
     
     
         54 . A system according to  claim 53 , wherein the device comprises a main body for housing the heating element and the heating element comprises an elongated heating element. 
     
     
         55 . A method of using the system according to  claim 53 , the method comprising:
 inserting the article into the device; and   heating the article using the heating element.   
     
     
         56 . A method according to  claim 55 , comprising inserting the article into a cavity within a main body of the device and penetrating the article with the heating element upon insertion of the article. 
     
     
         57 . An aerosol-forming article comprising an aerosol-forming substrate wherein the aerosol-forming substrate comprises a first, upstream portion of aerosol-forming material and a second, downstream portion of aerosol-forming material wherein the first and second portions of aerosol-forming material are axially spaced by a cavity housing a vapour modifier. 
     
     
         58 . An aerosol-forming article according to  claim 57  wherein the first portion of aerosol-forming material and the second portion of aerosol-forming material are both formed of a first aerosol-forming material. 
     
     
         59 . An aerosol-forming article according to  claim 58  wherein the vapour modifier comprises a second aerosol-forming material. 
     
     
         60 . An aerosol-forming article according to claim  059  wherein the second aerosol-forming material is extruded tobacco. 
     
     
         61 . An aerosol-forming article according to  claim 60  wherein the second aerosol-forming material is extruded tobacco chips/pellets/granules. 
     
     
         62 . An aerosol-forming article according to any one of  claims 58  to  61  wherein the first aerosol-forming material comprises one or more of tobacco, tobacco derivatives, expanded tobacco, shredded tobacco and/or reconstituted tobacco. 
     
     
         63 . An aerosol-forming article according to any one of the preceding claims wherein the vapour modifier is an additive carrier. 
     
     
         64 . An aerosol-forming article according to claim  063  wherein the additive carrier is a crushable or meltable capsule. 
     
     
         65 . An aerosol-forming article according to claim  063  or  64  wherein the additive carrier contains a humectant or a flavourant. 
     
     
         66 . A smoking substitute system comprising an article according to any one of the preceding claims and a device comprising a heating element. 
     
     
         67 . A system according to claim  066  wherein the device comprises a main body for housing the heating element and the heating element comprises an elongated heating element. 
     
     
         68 . A method of using the system according to claim  066  or  67 , the method comprising: inserting the article into the device; and heating the article using the heating element. 
     
     
         69 . A method according to claim  068  comprising inserting the article into a cavity within a main body of the device and penetrating the article with the heating element upon insertion of the article. 
     
     
         70 . A filter element for an aerosol-forming article, the filter element comprising a bundle of filter tows with a bore extending longitudinally therethrough, at least a portion of the bore having a non-circular transverse cross-section. 
     
     
         71 . A filter element according to  claim 70 , wherein the transverse cross-section of the at least a portion of the bore comprises a central portion and a plurality of lobes projecting outwardly from the central portion. 
     
     
         72 . A filter element according to  claim 70 , wherein the transverse cross-section of at least a portion of the bore is any one of a square, triangle, heart shape, star shape or asterisk shape. 
     
     
         73 . A filter element according to  claim 70 , wherein the transverse cross-sectional area of the bore is substantially uniform for the entire axial length of the bore. 
     
     
         74 . A filter element according to  claim 70 , wherein the shape of the transverse cross-section of the bore is substantially uniform for the entire length of the bore. 
     
     
         75 . A filter element according to  claim 70 , comprising a plurality of bores, at least a portion of each of the plurality of bores having a non-circular transverse cross-section. 
     
     
         76 . An aerosol-forming article comprising an aerosol-forming substrate and a filter element according to  claim 70 , downstream of the aerosol-forming substrate. 
     
     
         77 . An aerosol-forming article according to  claim 76 , wherein the filter element is a terminal filter element located at a downstream axial end of the aerosol-forming article. 
     
     
         78 . An aerosol-forming article according to  claim 76 , that is a heat-not-burn (HNB) consumable. 
     
     
         79 . A system comprising an aerosol-forming article according to  claim 70 , and a device comprising a heating element. 
     
     
         80 . A system according to  claim 79 , wherein the device comprises a main body for housing the heating element and the heating element comprises an elongated heating element. 
     
     
         81 . A method of using the system according to  claim 79 , the method comprising:
 inserting the article into the device; and   heating the article using the heating element.   
     
     
         82 . A method according to  claim 81 , comprising inserting the article into a cavity within a main body of the device and penetrating the article with the heating element upon insertion of the article. 
     
     
         83 . An aerosol-forming article comprising an aerosol-forming substrate wherein the aerosol-forming substrate comprises at least a first aerosol-forming material and a second aerosol forming material wherein the first and second aerosol-forming materials are axially and/or radially segregated within the aerosol-forming substrate. 
     
     
         84 . An aerosol-forming article according to  claim 83 , wherein the aerosol-forming materials are axially segregated and the aerosol-forming substrate comprises at least a first rod- or tube-shaped portion and a second rod- or tube-shaped portion. 
     
     
         85 . An aerosol-forming article according to  claim 84 , wherein the first and second rod/tube portions are axially adjacent one another within the substrate. 
     
     
         86 . An aerosol-forming article according to  claim 83 , wherein the aerosol-forming materials are radially segregated and the aerosol-forming substrate comprises at least a first, radially outer rod- or tube-shaped portion (formed of the first aerosol-forming material) and a second, radially inner tube-shaped portion (formed of the second aerosol-forming material). 
     
     
         87 . An aerosol-forming article according to  claim 86 , wherein the first and second rod/tube portions are radially adjacent one another. 
     
     
         88 . An aerosol-forming article according to  claim 83 , wherein one of the first and second aerosol-forming materials comprises extruded tobacco. 
     
     
         89 . An aerosol-forming article according to  claim 88 , wherein the extruded tobacco is in the form of a rod- or tube-shaped extrudate or chips/granules/pellets. 
     
     
         90 . A smoking substitute article according to  claim 83 , wherein one of the first and second aerosol-forming materials comprises reconstituted tobacco and the other comprises extruded tobacco. 
     
     
         91 . A smoking substitute system comprising an article according to  claim 83 , and a device comprising at least one heating element. 
     
     
         92 . A system according to  claim 91 , wherein the device comprises a first heating element for heating the first aerosol-forming material within the substrate and a second heating element for heating the second aerosol forming material. 
     
     
         93 . A system according to  claim 92 , wherein the first and second heating elements are separately controllable. 
     
     
         94 . A method of using the system according to  claim 91 , the method comprising: inserting the article into the device; and heating the article using the heating element(s). 
     
     
         95 . A method according to  claim 94 , comprising heating the first aerosol-forming material in the aerosol-forming substrate using a the first heating element and heating the second aerosol-forming material in the aerosol-forming substrate using the second heating element. 
     
     
         96 . A method according to  claim 95 , comprising heating the first aerosol-forming material at a different rate and/or temperature than the second aerosol-forming material. 
     
     
         97 . An aerosol-forming article comprising an aerosol-forming substrate and a terminal filter element, wherein the terminal filter element comprises an upstream filter portion and an axially adjacent downstream filter portion, and wherein one of the upstream and downstream filter portions is a hollow bore filter element and the other is a solid filter element. 
     
     
         98 . An aerosol-forming article according to  claim 97 , wherein the upstream filter portion is the solid filter element, and the downstream filter portion is the hollow bore filter element. 
     
     
         99 . An aerosol-forming article according to  claim 97 , wherein the terminal filter element has an axial length of between 11 mm and 13 mm. 
     
     
         100 . An aerosol-forming article according to  claim 97 , wherein the upstream filter portion and the downstream filter portion have substantially the same axial length. 
     
     
         101 . An aerosol-forming article according to  claim 100 , wherein the axial length of each of the upstream and downstream filter portions is around 6 mm. 
     
     
         102 . An aerosol-forming article according to  claim 97 , wherein the upstream and downstream filter portions are joined by way of a plug wrap at least partly circumscribing the upstream and downstream filter portions. 
     
     
         103 . An aerosol-forming article according to  claim 97 , wherein the filter portion that is the solid filter element comprises a flavourant. 
     
     
         104 . An aerosol-forming article according to  claim 97 , further comprising a hollow bore upstream filter element located between the aerosol-forming substrate and the terminal filter element. 
     
     
         105 . An aerosol-forming article according to  claim 97 , wherein the article is a heat not burn (HNB) consumable. 
     
     
         106 . A method of forming an aerosol-forming article, the method comprising:
 joining a first filter portion to a second filter portion to form a terminal filter element; and   combining the terminal filter element with an aerosol-forming substrate to form the aerosol-forming article.   
     
     
         107 . A method according to  claim 106 , wherein the first filter portion is a hollow bore filter element and the second filter portion is a solid filter element. 
     
     
         108 . A method according to  claim 106 , wherein the first and second filter portions are joined by a plug wrap. 
     
     
         109 . A method according to  claim 106 , wherein the combined axial length of the first and second filter portions is around 12 mm and the step of combining the terminal filter element with the substrate is performed using a combining machine configured for combining terminal filter elements having an axial length of 12 mm. 
     
     
         110 . A system comprising a smoking substitute article according to  claim 97 , and a device comprising a heating element. 
     
     
         111 . A system according to  claim 110 , wherein the device comprises a main body for housing the heating element and the heating element comprises an elongated heating element. 
     
     
         112 . A method of using the system according to  claim 110 , the method comprising:
 inserting the article into the device; and   heating the article using the heating element.   
     
     
         113 . A method according to  claim 112  comprising inserting the article into a cavity within a main body of the device and penetrating the article with the heating element upon insertion of the article. 
     
     
         114 . An aerosol-forming article comprising an aerosol-forming substrate at least partly comprising a rod of extruded plant material wherein the article further comprises a terminal filter element at the downstream axial end and an upstream filter element upstream and axially spaced from the terminal filter element. 
     
     
         115 . An article according to  claim 114 , wherein the article is a heat not burn (HNB) consumable. 
     
     
         116 . An article according to  claim 114 , wherein the rod of extruded plant material has an axial bore adapted to receive an external heating element. 
     
     
         117 . An article according to  claim 114 , wherein the aerosol-forming substrate comprises a rod of extruded tobacco. 
     
     
         118 . An article according to  claim 114 , wherein the aerosol-forming substrate further comprises one or more additives selected from humectants, fillers, solvents, flavourants, and binders. 
     
     
         119 . An article according to  claim 114 , wherein the upstream filter element and terminal filter element are axially spaced by a cooling element or a spacer. 
     
     
         120 . An article according to  claim 114 , wherein the upstream filter element is axially adjacent the aerosol-forming substrate. 
     
     
         121 . An article according to  claim 114 , wherein the filter element and/or the terminal filter element is/are a hollow bore element. 
     
     
         122 . An article according to  claim 121 , wherein both the upstream and terminal filer elements are hollow bore filter elements. 
     
     
         123 . A smoking substitute system comprising an article according to an  claim 114 , and a device comprising a heating element. 
     
     
         124 . A system according to  claim 123 , wherein the device comprises a main body for housing the heating element and the heating element comprises an elongated heating element. 
     
     
         125 . A method of using the system according to  claim 123 , the method comprising:
 inserting the article into the device; and   heating the article using the heating element.   
     
     
         126 . A heat not burn consumable comprising an aerosol-forming substrate and a terminal filter element, wherein the axial length of the terminal filter element is adjustable. 
     
     
         127 . A consumable according to  claim 126 , wherein the terminal filter element comprises a plurality of filter portions in axial abutment with one another and wherein one or more of the filter portions is/are removable from the consumable to adjust the axial length of the terminal filter element. 
     
     
         128 . A consumable according to  claim 126 , wherein the terminal filter element comprises a hollow bore filter portion. 
     
     
         129 . A consumable according to  claim 128 , wherein the hollow bore filter portion is upstream from the downstream axial end of the consumable. 
     
     
         130 . A consumable according to  claim 129 , further comprising a solid filter portion at the axial downstream end of the consumable. 
     
     
         131 . A consumable according to  claim 127 , wherein the terminal filter element is circumscribed by a tipping paper and wherein the tipping paper comprises a region of weakness aligned with a join between two filter portions. 
     
     
         132 . A consumable according to  claim 131 , wherein the region of weakness comprises an array of perforations in the tipping paper. 
     
     
         133 . An aerosol-forming article comprising an aerosol-forming substrate and a terminal filter element wherein the axial length of the terminal filter element is adjustable and wherein the terminal filter element comprises a hollow bore filter portion and a solid filter portion. 
     
     
         134 . An article according to  claim 133 , wherein the terminal filter element is circumscribed by a tipping paper and wherein the tipping paper comprises a region of weakness aligned with a join between the two filter portions. 
     
     
         135 . An article according to  claim 134 , wherein the region of weakness comprises an array of perforations in the tipping paper. 
     
     
         136 . A system comprising a consumable or an article according to  claim 126 , and a device comprising a heating element. 
     
     
         137 . A system according to  claim 136 , wherein the device comprises a main body for housing the heating element and the heating element comprises an elongated heating element. 
     
     
         138 . A method of using the system according to  claim 136 , the method comprising:
 inserting the consumable/article into the device; and   heating the consumable/article using the heating element.   
     
     
         139 . A method according to  claim 135 , comprising inserting the consumable/article into a cavity within a main body of the device and penetrating the consumable/article with the heating element upon insertion of the consumable. 
     
     
         140 . A method according to  claim 135 , comprising reducing the axial length of the terminal filter element. 
     
     
         141 . An aerosol-forming article comprising an aerosol-forming substrate and a plurality of filter elements having different axial lengths. 
     
     
         142 . An article according to  claim 141 , wherein the article is a heat-not-burn (HNB) consumable. 
     
     
         143 . An article according to  claim 141 , comprising a terminal filter element at the downstream/mouth end of the article and an upstream filter element upstream of the terminal filter element. 
     
     
         144 . An article according to  claim 143 , wherein the axial length of the terminal filter element is greater than the axial length of the upstream filter element. 
     
     
         145 . An article according to  claim 143 , wherein the axial length of the terminal filter element is 2 mm or more greater than the axial length of the upstream filter element. 
     
     
         146 . An article according to  claim 143 , wherein the terminal filter element is a hollow bore filter element. 
     
     
         147 . An article according to  claim 146 , wherein the upstream filter element is a hollow bore filter element. 
     
     
         148 . An article according to  claim 147 , wherein the terminal filter element has an axial bore having a smaller diameter than an axial bore in the upstream filter element. 
     
     
         149 . An article according to  claim 143 , wherein the upstream filter element has a greater porosity than the terminal filter element. 
     
     
         150 . An article according to  claim 143 , wherein the upstream filter element and terminal filter element are spaced by an aerosol-cooling element and/or a spacer element. 
     
     
         151 . A system comprising a smoking substitute article according to  claim 143 , and a device comprising a heating element. 
     
     
         152 . A system according to  claim 151 , wherein the device comprises a main body for housing the heating element and the heating element comprises an elongated heating element. 
     
     
         153 . A method of using the system according to  claim 151 , the method comprising:
 inserting the article into the device; and   heating the article using the heating element.   
     
     
         154 . A method according to  claim 153 , comprising inserting the article into a cavity within a main body of the device and penetrating the article with the heating element upon insertion of the article. 
     
     
         155 . An aerosol-forming article comprising an aerosol-forming substrate and a plurality of hollow bore filter elements having different internal bore diameters. 
     
     
         156 . An article according to  claim 155 , wherein the article is a heat-not-burn (HNB) consumable. 
     
     
         157 . An article according to  claim 155 , comprising a terminal hollow bore filter element at the downstream/mouth end of the article and an upstream hollow bore filter element upstream of the terminal filter element. 
     
     
         158 . An article according to  claim 157 , wherein the terminal hollow bore filter element has an axial bore having a smaller diameter than an axial bore in the upstream hollow bore filter element. 
     
     
         159 . An article according to  claim 158 , wherein the diameter of the axial bore in the upstream hollow bore filter element is at least 1 mm greater than the diameter of the axial bore in the terminal filter element. 
     
     
         160 . An article according to  claim 157 , wherein the axial length of the terminal hollow bore filter element is greater than the axial length of the upstream hollow bore filter element. 
     
     
         161 . An article according to  claim 160 , wherein the axial length of the terminal hollow bore filter element is 2 mm or more greater than the axial length of the upstream hollow bore filter element. 
     
     
         162 . An article according to  claim 157 , wherein the upstream hollow bore filter element has a greater porosity than the terminal hollow bore filter element. 
     
     
         163 . An article according to  claim 157 , wherein the upstream hollow bore filter element and terminal hollow bore filter element are spaced by an aerosol-cooling element and/or a spacer element. 
     
     
         164 . A system comprising a smoking substitute article according to  claim 157 , and a device comprising a heating element. 
     
     
         165 . A system according to  claim 164 , wherein the device comprises a main body for housing the heating element and the heating element comprises an elongated heating element. 
     
     
         166 . A system according to  claim 164 , comprising a rod-shaped heater having an external diameter wherein the internal diameter of the bore of the upstream hollow bore filter element is greater than the external diameter of the rod-shaped heater. 
     
     
         167 . A method of using the system according to  claim 164 , the method comprising:
 inserting the article into the device; and   heating the article using the heating element.   
     
     
         168 . A method according to  claim 167 , comprising inserting the article into a cavity within a main body of the device and penetrating the article with the heating element upon insertion of the article. 
     
     
         169 . An aerosol-forming article comprising an aerosol-forming substrate and a plurality of filter elements wherein at least two of the filter elements have different hardness from one another. 
     
     
         170 . An article according to  claim 169 , wherein the article is a heat-not-burn (HNB) consumable. 
     
     
         171 . An article according to  claim 169 , comprising a terminal filter element at the downstream/mouth end of the article and an upstream filter element upstream of the terminal filter element. 
     
     
         172 . An article according to  claim 171 , wherein the hardness of the terminal filter element is greater than the hardness of the upstream filter element. 
     
     
         173 . An article according to  claim 172 , wherein the hardness of the terminal filter element is at least 3% greater than the hardness of the upstream filter element. 
     
     
         174 . An article according to  claim 171 , wherein the axial length of the terminal filter element is greater than the axial length of the upstream filter element. 
     
     
         175 . An article according to  claim 174 , wherein the axial length of the terminal filter element is 2 mm or more greater than the axial length of the upstream filter element. 
     
     
         176 . An article according to  claim 171 , wherein the terminal filter element is a hollow bore filter element. 
     
     
         177 . An article according to  claim 176 , wherein the upstream filter element is a hollow bore filter element. 
     
     
         178 . An article according to  claim 177 , wherein the terminal filter element has an axial bore having a smaller diameter than an axial bore in the upstream filter element. 
     
     
         179 . An article according to  claim 171 , wherein the upstream filter element and terminal filter element are spaced by an aerosol-cooling element and/or a spacer element. 
     
     
         180 . A system comprising a smoking substitute article according to  claim 171 , and a device comprising a heating element. 
     
     
         181 . A system according to  claim 180 , wherein the device comprises a main body for housing the heating element and the heating element comprises an elongated heating element. 
     
     
         182 . A method of using the system according to  claim 180 , the method comprising:
 inserting the article into the device; and   heating the article using the heating element.   
     
     
         183 . A method according to  claim 181 , comprising inserting the article into a cavity within a main body of the device and penetrating the article with the heating element upon insertion of the article. 
     
     
         184 . An aerosol-forming article comprising an aerosol-forming substrate and a hollow bore terminal filter element at a downstream axial end of the article/consumable wherein the article comprises at least one radial air flow path into the aerosol-forming substrate. 
     
     
         185 . An article according to  claim 184 , wherein the article is a heat-not-burn (HNB) consumable. 
     
     
         186 . An article according to  claim 184 , comprising a plurality of radial air flow paths which may be circumferentially-arranged around the aerosol-forming article. 
     
     
         187 . An article according to  claim 184 , wherein the aerosol-forming substrate is circumscribed by a wrapping layer and the radial air flow path(s) may be provided by one or more ventilation holes provided in the wrapping layer. 
     
     
         188 . An article according to  claim 184 , further comprising a spacer element or an aerosol-cooling element upstream and axially adjacent the terminal filter element. 
     
     
         189 . An article according to  claim 184 , further comprising an upstream filter element provided upstream of terminal filter element and downstream of the aerosol-forming substrate. 
     
     
         190 . An article according to  claim 189  wherein the upstream filter element is a hollow bore filter element. 
     
     
         191 . An article according to  claim 184 , wherein the aerosol-forming substrate comprises a gathered sheet of homogenised tobacco or gathered shreds/strips formed from such a sheet. 
     
     
         192 . An article according to  claim 184 , wherein the aerosol-forming substrate further comprises one or more additives selected from humectants, flavourants, fillers, aqueous/non-aqueous solvents and binders. 
     
     
         193 . A system comprising a smoking substitute article according to  claim 184 , and a device comprising a heating element. 
     
     
         194 . A system according to  claim 193 , wherein the device comprises a main body for housing the heating element and the heating element comprises an elongated heating element. 
     
     
         195 . A method of using the system according to  claim 193 , the method comprising:
 inserting the article into the device; and   heating the article using the heating element.   
     
     
         196 . A method according to  claim 195 , comprising inserting the article into a cavity within a main body of the device and penetrating the article with the heating element upon insertion of the article. 
     
     
         197 . An aerosol-forming article comprising an aerosol-forming substrate and a terminal filter element at the downstream axial end of the article wherein the terminal filter element comprises an adsorbent additive. 
     
     
         198 . An article according to  claim 197 , wherein the adsorbent additive is selected from one or more of a zeolite, an activated carbon, a silica gel, a clay, a porous polymer and activated alumina. 
     
     
         199 . An article according to  claim 198 , wherein the adsorbent is activated carbon. 
     
     
         200 . An article according to  claim 197 , wherein the terminal filter element comprises a terminal filter portion and an upstream filter portion and wherein at least a portion of adsorbent additive is sandwiched between the upstream filter portion and the terminal filter portion. 
     
     
         201 . An article according to  claim 197 , wherein the adsorbent additive is evenly distributed throughout the terminal filter portion. 
     
     
         202 . An article according to  claim 197 , further comprising an upstream filter element. 
     
     
         203 . An article according to  claim 202 , wherein the terminal filter element and the upstream filter element are axially spaced by an aerosol-cooling element and/or a spacer element. 
     
     
         204 . An aerosol-forming article comprising an aerosol-forming substrate and at least one filter element wherein the at least one filter element comprises at least one polar solvent. 
     
     
         205 . An aerosol-forming article according to  claim 204 , wherein the at least one polar solvent is one or more polar solvents selected from water and polar organic solvents. 
     
     
         206 . An aerosol-forming article according to  claim 205 , wherein the polar organic solvent(s) is/are selected from ethanol, isopropyl alcohol and dimethylsulfoxide. 
     
     
         207 . An aerosol-forming article according to  claim 204 , wherein the at least one polar solvent is evenly distributed throughout the filter element. 
     
     
         208 . An aerosol-forming article according to  claim 204 , wherein the at least one polar solvent is concentrated in discrete regions within the filter element. 
     
     
         209 . An aerosol-forming article according to  claim 208 , wherein the polar solvent is contained in one or more frangible capsules. 
     
     
         210 . An aerosol-forming article according to  claim 209 , wherein the or each capsule is a crushable capsule configured to break and release the polar solvent when crushed. 
     
     
         211 . An aerosol-forming article according to  claim 209 , wherein the or each capsule is a thermally labile capsule configured to melt/deform and release the polar solvent when heated. 
     
     
         212 . An aerosol-forming article according to  claim 204 , wherein the filter element is a terminal filter element. 
     
     
         213 . A method comprising: using a polar solvent in a filter element of an aerosol-forming article to filter hazardous substances from an aerosol that is drawn through the filter element. 
     
     
         214 . The method according to  claim 213 , wherein the aerosol forming article comprises an aerosol-forming substrate and at least one filter element wherein the at least one filter element comprises at least one polar solvent. 
     
     
         215 . An article according to  claim 197 , wherein the article is a heat not burn (HNB) consumable. 
     
     
         216 . A system comprising an article according to  claim 197  a device comprising a heating element. 
     
     
         217 . A system according to  claim 216  wherein the device comprises a main body for housing the heating element and the heating element comprises an elongated heating element. 
     
     
         218 . A method of using the system according to  claim 216 , the method comprising:
 inserting the article into the device; and   heating the article using the heating element.   
     
     
         219 . A method according to  claim 218 , comprising inserting the article into a cavity within a main body of the device main body and penetrating the article with the heating element upon insertion of the article. 
     
     
         220 . An aerosol-forming article comprising an aerosol-forming substrate and at least one filter element downstream of the substrate wherein the at least one filter element is a hollow bore filter element and wherein the article has at least one unimpeded flow path along the outer surface of the filter element. 
     
     
         221 . An article according to  claim 220  wherein the article is a heat-not-burn (HNB) consumable. 
     
     
         222 . A heat-not-burn (HNB) consumable comprising an aerosol-forming substrate and at least one filter element downstream of the substrate wherein the consumable has at least one unimpeded flow path along the outer surface of the filter element. 
     
     
         223 . The consumable of  claim 222  wherein the filter element is a solid filter element. 
     
     
         224 . The consumable of  claim 222 , wherein the filter element has an outer surface comprising a plurality of longitudinally-extending channels. 
     
     
         225 . The consumable of  claim 222 , further comprising a sleeve circumscribing the filter element. 
     
     
         226 . The consumable of  claim 222 , wherein the filter element comprises a flavourant. 
     
     
         227 . The consumable according to  claim 226 , wherein the filter element comprises a longitudinally-extending thread carrying the flavourant. 
     
     
         228 . The consumable of  claim 222 , wherein the filter element is a terminal filter element provided at the downstream axial end of the article/consumable. 
     
     
         229 . The consumable according to  claim 228 , further comprising an upstream filter element upstream from the terminal filter element. 
     
     
         230 . The consumable according to  claim 229 , wherein the terminal filter element and the upstream filter element are axially spaced by an aerosol-cooling element and/or a spacer element. 
     
     
         231 . A system comprising the consumable according to  claim 222 , and a device comprising a heating element. 
     
     
         232 . A system according to  claim 231 , wherein the device comprises a main body for housing the heating element and the heating element comprises an elongated heating element. 
     
     
         233 . A method of using the system according to  claim 231 , the method comprising:
 inserting the consumable into the device; and   heating the consumable using the heating element.   
     
     
         234 . A method according to  claim 233 , comprising inserting the consumable into a cavity within a main body of the device and penetrating the consumable with the heating element upon insertion of the consumable.