An aerosol-generating article and a method for removing humidity therein

Abstract

An aerosol-generating article (1) comprises an aerosol-generating substrate (2) extending along a longitudinal direction; a filter portion (3) arranged downstream of the aerosol-generating substrate (2) and extending along the longitudinal direction; wherein the aerosol-generating substrate (2) presents a first end (2a) proximal to the filter portion (3) and a second end (2b) opposed to the first end (2a) in the longitudinal direction; the aerosol- generating article (1) further comprises means for generating an electrical field (4) arranged at the aerosol-generating substrate (2) to generate electrolysis of water contained in the aerosol generating substrate (2). A method for removing humidity in an aerosol-generating article (1) comprises the step of applying an electrical field to the aerosol-generating substrate (2).

Description

[0001] An aerosol -generating article and a method for removing humidity therein

[0002] Technical field

[0003] The present invention relates to an aerosol-generating article and a method for removing humidity therein .

[0004] For example , the present invention is applicable to heated tobacco stick (HTS ) used in heat-not-burn (HNB ) devices .

[0005] Background

[0006] Known tobacco sticks for use in Heat-not-burn devices comprise humectants such as glycerin to maintain the correct level of humidity in order to preserve the properties of tobacco over time .

[0007] The standard humectants are hygroscopic and determine non- negligible accumulation of water inside the stick, in case the stick is used at tropical regions or is stored for long period .

[0008] When the stick is heated in the heat-not-burn device , the user may experience unpleasant much vapor during the first puf f due to the energy employed in the vapori zation of water contained in the stick .

[0009] Therefore , the first puf f of the known tobacco stick may be unpleasant for many users .

[0010] Summary of the Invention

[0011] In view of the above , it is an obj ect of the present invention to provide an aerosol-generating article and a method for removing humidity therein configured or designed to deliver an improved sensory experience to users thereof . This is achieved by means of the article described in claim 1 and in the method according to claim 14 .

[0012] According to the invention, an aerosol-generating article comprises an aerosol-generating substrate extending along a longitudinal direction, a filter portion arranged downstream of the aerosol-generating substrate and extending along the longitudinal direction; the aerosol-generating substrate presents a first end proximal to the filter portion and a second end opposed to the first end in the longitudinal direction . The aerosol-generating article further comprises means for generating an electrical field arranged at the aerosol-generating substrate to generate electrolysis of water contained in the aerosol-generating substrate .

[0013] When the aerosol-generating article is in use , the molecules of water contained in the aerosol-generating substrate and exposed to the electrical field generated by the means for generating an electrical field disassociate in molecules of gaseous oxygen ( O2 ) and hydrogen (H2) through an electrolysis process .

[0014] In this way, the gaseous oxygen and hydrogen are removed from the aerosol-generating article without containing much vapor to first puf f .

[0015] When in use , the aerosol-generating article is introduced in an aerosol-generating device which heats the article . When the means for generating an electrical field are activated during the warm-up of the device , the user may experience a first puf f bringing good sensory experience as water contained in the aerosol-generating substrate has been removed by electrolysis .

[0016] The first puf f experience is therefore signi ficantly improved for the user . According to a preferred aspect of the invention, the means for generating an electrical field may comprise a first electrode and a second electrode . Preferably, the aerosol generating substrate may be arranged at least in part between the first electrode and the second electrode .

[0017] This configuration ensures that the electrical field is applied to the aerosol-generating substrate to ef fectively remove water contained therein .

[0018] According to a preferred aspect of the invention, the means for generating an electrical field may comprise a first contact portion and a second contact portion, each connected to the corresponding first and second electrode . Preferably, the first contact portion and the second contact portion being configured to be applied voltage .

[0019] This configuration allows a proper connection with a power source of an aerosol-generating device in order to apply a voltage to the electrodes generating the electrical field .

[0020] According to a preferred aspect of the invention, the first electrode may comprise a conductive plate arranged orthogonal to the longitudinal direction at the first end of the aerosol-generating substrate .

[0021] The conductive plate arranged orthogonal to the longitudinal direction allows the generation of a uni form electrical field which determines an ef fective and uni form electrolysis of water contained in the aerosol-generating substrate .

[0022] According to a preferred aspect o f the invention, the second electrode may comprise at least a conductive rod arranged at the second end of the aerosol generating substrate . This configuration allows the second electrode to be introduced in the aerosol-generating substrate in a simple and quick way . The manufacturing process of the aerosolgenerating article is then simpli fied .

[0023] According to a preferred aspect of the invention, the aerosol-generating article may further comprise a front plug arranged at the second end of the aerosol generating substrate . Preferably, at least a rod may penetrate the front plug .

[0024] The front plug allows a fixed pos itioning of the rod in the aerosol-generating substrate and, consequently, the generation of a stable electrical field .

[0025] According to a preferred aspect of the invention, the first electrode may comprise a conductive plate arranged orthogonal to the longitudinal direction at the first end of the aerosol generating substrate , wherein the second electrode may comprise a conductive plate arranged orthogonal to the longitudinal direction at the second end of the aerosol generating substrate , and preferably the conductive plate o f the first electrode and the conductive plate of the second electrode may comprise a plurality of spikes extending from the respective conductive plate towards the opposite one .

[0026] The spikes connected to the conductive plates allow the electrical field to be locally higher in intensity due to the corona ef fect . This determines a locally increased electrolysis ef fect of the water contained in the aerosolgenerating substrate .

[0027] The conductive plates may mechanically support the spikes and fairly apply electrical potential to each spike .

[0028] According to a preferred aspect of the invention, the first electrode and the second electrode may comprise respective conductive sheets arranged at a lateral surface of the aerosol generating substrate along the longitudinal direction . Preferably, the conductive sheets may present a cross-section with reference to the longitudinal direction shaped as a circumferential arc so as to cover the aerosol generating substrate .

[0029] This configuration allows the electrodes to envelope the aerosol-generating substrate in a more easy and ef ficient way so that an ef fective electrical field is generated on the substrate .

[0030] According to a preferred aspect of the invention, the conductive sheets may comprise a plurality of spikes extending in the aerosol generating substrate .

[0031] The presence of the spikes connected to the conductive sheets allow the electrical field to be locally higher in intensity due to the corona ef fect . This determines a locally increased electrolysis ef fect of the water contained in the aerosolgenerating substrate .

[0032] According to a preferred aspect of the invention, the first electrode may comprise a first cylindrical sheet arranged at a lateral surface of the aerosol generating substrate along the longitudinal direction and wherein the second electrode may comprise a second cylindrical sheet having a diameter smaller than the diameter of the first cylindrical sheet and arranged coaxially to the first cylindrical sheet along the longitudinal direction .

[0033] Due to this configuration, it is possible to create an intense and uni form electrical field able to promote an ef fective electrolysis of the water contained between the sheets . According to a preferred aspect of the invention, the first cylindrical sheet and / or the second cylindrical sheet may comprise a plurality of spikes extending in the aerosol generating substrate .

[0034] The spikes connected to the first and / or second cylindrical sheet allow the electrical field to be locally higher in intensity due to the corona ef fect . This determines a locally increased electrolysis ef fect of the water contained in the aerosol-generating substrate .

[0035] According to a preferred aspect of the invention, the aerosol-generating article may further comprise a front plug arranged at the second end of the aerosol generating substrate and the second cylindrical sheet may penetrate the front plug .

[0036] The front plug allows a fixed positioning of the second cylindrical sheet in the aerosol-generating substrate and, consequently, the generation of a stable electrical field .

[0037] According to a preferred aspect of the invention, the aerosol-generating article may further comprise a cigarette paper at least enveloping the aerosol generating substrate wherein the first contact portion and / or second contact portion may comprise a conductive portion of the cigarette paper impregnated with a conductive ink .

[0038] This allows to easily and quickly create the contact portions . Therefore , the manufacturing process of the aerosol-generating article can be simpli fied .

[0039] According to the invention, a method for removing humidity in the aerosol-generating article of the invention comprises the step of applying an electrical field in the aerosol generating substrate through means for generating an electrical field to generate electrolysis of water contained in the aerosol generating substrate ; and wherein the step o f applying an electrical field in the aerosol generating substrate comprises the step of applying a voltage between the first electrode and the second electrode .

[0040] The method of the invention allows the first puf f experience to be signi ficantly improved for the user .

[0041] Indeed, in use , the generation of the electrical field determines the removal of water contained in the aerosolgenerating substrate through electrolysis by dissociating water in gaseous oxygen and hydrogen .

[0042] According to a preferred aspect o f the invention, the method may further comprise a step of j udging a completion of preheating and / or removing humidity when a value of current flowing through between the first electrode and the second electrode is below a predetermined threshold value .

[0043] This allows to ef ficiently manage the power supply . Indeed, the correct evaluation of the completion of pre-heating and / or removing humidity allows to stop the power supply to the means for generating the electrical field when the removal of water from the aerosol-generating substrate is not necessary anymore .

[0044] Brief Description of the Drawings

[0045] Hereinafter, the invention will be further described with reference to a preferred embodiment thereof , in which

[0046] Fig . 1 shows a schematic view of an aerosol-generating article according to a first embodiment of the present invention; Fig . 2 shows a schematic view of an aerosol-generating article according to a second embodiment of the present invention;

[0047] Fig . 3 shows a schematic view of an aerosol-generating article according to a third embodiment of the present invention;

[0048] Fig . 4 shows a schematic view of an aerosol-generating article according to a first embodiment of the present invention;

[0049] Fig . 5 shows a schematic view of detail of the aerosolgenerating article according to the first or second embodiment of the present invention .

[0050] Detailed Description of Preferred Embodiments

[0051] As can be seen in Figs . 1 to 4 , the aerosol-generating article 1 according to the invention comprises an aerosolgenerating substrate 2 extending along a longitudinal direction and a filter portion 3 arranged downstream of the aerosol generating substrate 2 and extending along the longitudinal direction .

[0052] The term "downstream" refers to the flow of air passing through the aerosol-generating article 1 during use , and in particular during a puf f of the user .

[0053] The aerosol-generating substrate 2 presents a first end 2a proximal to the filter portion 3 and a second end 2b opposed to the first end 2a in the longitudinal direction .

[0054] In other words , the filter portion 3 is connected with the aerosol-generating substrate 2 at the first end 2a of the aerosol-generating substrate 2 , optionally by means of hollow space to condensate aerosol . In other words , the filter portion 3 is adj acent to the first end 2a of the aerosolgenerating substrate 2 .

[0055] The aerosol-generating substrate 2 may comprise a plantfilling material comprising tobacco material , botanicals , or a combination thereof . When comprising tobacco material , the latter may comprise lamina and / or stems . It may also alternatively or in combination comprise reconstituted tobacco sheet materials formed of dry tobacco leaves in particulate form so as to have a mean particle si ze of 20 pm or more but not more than 200 pm, which are then homogeni zed into a sheet-processed material . The aerosol-generating substrate 2 content is typically between about 200 mg and 800 mg, preferably between 250 mg and 350 mg for a 20 mm length and 22 mm circumference .

[0056] Various kinds of tobacco leaves can be used for making a tobacco containing aerosol generating substrate to achieve the desired taste .

[0057] In addition, the aerosol-generating substrate 2 may preferably comprise an aerosol former such as Glycerine , Propylene Glycol , triacetin, 1 , 3-butanediol and blends thereof in weight contents of between about 5 wt . % or more , preferably 10 wt . % or more , usually 50 wt . % or less , preferably 15 wt . % or more and 25 wt . % or less based on the total amount of the filling material .

[0058] The aerosol-generating substrate 2 is enveloped with cigarette paper 18 .

[0059] The filter portion 3 may comprise a filter plug that can be an acetate or paper filter enveloped with a filter paper (not shown) .

[0060] The filter portion 3 is connected to the aerosol-generating substrate 2 through a tipping paper (not shown) enveloped around the filter portion 3 and at least part of the aerosolgenerating substrate 2 .

[0061] According to the invention, the aerosol-generating article 1 further comprises means for generating an electrical field 4 arranged at the aerosol generating substrate 2 to generate electrolysis of water contained in the aerosol generating substrate 2 . The means for generating an electrical field 4 may be an electrical field generating element .

[0062] In detail , the electrical field generated by the means for generating an electrical field 4 hits the molecules of water contained in the aerosol-generating substrate and determines the disassociation of the water molecules in molecules of gaseous oxygen ( O2) and hydrogen (H2) , through an electrolysis process , which are then removed from the aerosol-generating article 1 through the air flow .

[0063] Preferably, the means for generating an electrical field 4 comprises a first electrode 5 and a second electrode 6 and the aerosol-generating substrate 2 is arranged at least in part between the first electrode 5 and the second electrode 6 .

[0064] As a mere example , the first electrode 5 can be a negative electrode ( cathode ) at which gaseous hydrogen (H2) is generated during electrolysis and the second electrode 6 can be a positive ( anode ) at which gaseous oxygen ( O2) is generated during electrolysis .

[0065] Alternatively, the first electrode 5 can be a positive electrode ( anode ) and the second electrode 6 can be a negative ( cathode ) .

[0066] Additionally, the means for generating an electrical field 4 may comprise a first contact portion 7 and a second contact portion 8 . The first contact portion 7 is connected to the first electrode 5 and the second contact portion 8 is connected to the second electrode 6 .

[0067] The first contact portion 7 and the second contact portion 8 are configured to be applied with a voltage necessary for the generation of the electrical field .

[0068] Preferably, the voltage to be applied to the first contact portion 7 and the second contact portion 8 may be 46 V to 50 V .

[0069] As a mere example , the voltage to be applied to the first contact portion 7 and the second contact portion 8 may be 48 V .

[0070] The first contact portion 7 and the second contact portion 8 are configured to be contacted by a first electrical terminal and a second electrical terminal , correspondingly, of an aerosol-generating device (not shown) in which the aerosolgenerating article of the invention is introduced to be heated .

[0071] In this regard, the aerosol-generating device may comprise a power source (not shown) configured to apply a voltage di f ference between the first electrical terminal and the second electrical terminal and, consequently, to the first contact portion 7 and the second contact portion 8 .

[0072] The first and second electrical terminals of the aerosolgenerating device are located in positions corresponding to the positions of the first contact portion 7 and the second contact portion 8 . The first and second electrical terminals of the aerosolgenerating device allow the voltage to be applied to the first contact portion 7 and the second contact portion 8 .

[0073] The aerosol-generating article 1 of the invention further comprises a front plug 11 arranged at the second end 2b o f the aerosol generating substrate 2 .

[0074] The front plug 11 may be made of acetate . The front plug 11 is enveloped in the cigarette paper 18 .

[0075] According to a first embodiment of the invention shown in Fig . 1 , the first electrode 5 comprises a conductive plate 9 arranged orthogonal to the longitudinal direction at the first end 2a of the aerosol generating substrate 2 .

[0076] In other words , the conductive plate 9 is arranged between the aerosol generating substrate 2 and the filter portion 3 .

[0077] The conductive plate 9 is made of a conductive material . Preferably, the conductive plate 9 is made of metal . As an example , the conductive plate 9 is made of copper, graphite or nickel .

[0078] Preferably, the conductive plate 9 is disk-shaped . Preferably, the diameter of the conductive plate 9 is substantially the same as that of the aerosol generating substrate 2 measured in a plane orthogonal to the longitudinal direction .

[0079] Alternatively, the conductive plate 9 can have any other proper shape and / or dimension as long as it does not exceed the transversal dimension of the aerosol-generating substrate 2 .

[0080] The conductive plate 9 may include pores of hole to discharge gaseous hydrogen (H2) and / or oxygen ( 02) . In the first embodiment , preferably, but not exclusively, the first contact portion 7 may comprise a conductive portion 19 of the cigarette paper 18 impregnated with a conductive ink ( see Fig . 5 ) .

[0081] As an example , the conductive ink may include silver particles and / or carbon particles .

[0082] The conductive ink impregnates the entire thickness of the cigarette paper 18 at the conductive portion 19 in such a way to allow the electrical connection between the corresponding electrical terminal of the aerosol-generating device and the conductive plate 9 .

[0083] According to the first embodiment , the second electrode 6 comprises at least a conductive rod 10 arranged at the second end 2b of the aerosol generating substrate 2 .

[0084] Preferably, the second electrode 6 comprises a plurality of conductive rods 10 arranged at the second end 2b of the aerosol generating substrate 2 .

[0085] The conductive rods 10 are made of a conductive material . Preferably, the conductive rods 10 are made of metal . As an example , the conductive rods 10 are made of copper, graphite or nickel .

[0086] The conductive rods 10 may be arranged parallel to each other in the longitudinal direction . Such arrangement may contribute uni formity of electrical field and avoiding unexpected contact among rods .

[0087] Alternatively, the conductive rods 10 may be arranged with di f ferent orientations with respect to the longitudinal direction . The conductive rods 10 may all have the same cross section . Preferably, the conductive rods 10 may all have a circular cross section .

[0088] The conductive rods 10 may all have the same length . This configuration may contribute alignment of electric field vector .

[0089] Alternatively, the conductive rods 10 may have di f ferent lengths as shown in Fig 1 . Such configuration may contribute various unaligned electric field vectors which occur electrolysis at a lot of positions in the aerosol generating substrate 2 .

[0090] Preferably, at least some of the conductive rods 10 protrude from the second end 2b of the aerosol-generating substrate 2 . To enhance discharging gaseous hydrogen (H2) and / or oxygen ( O2) from the aerosol generating substrate 2 , the first electrode 5 preferably includes pores or hole , as described above . It may not require to the second electrode 6 . Accordingly, the conductive rods 10 may be preferable to implement as the second end 2b of the aerosol-generating substrate 2 .

[0091] Preferably, at least one of the conductive rods 10 penetrates the front plug 11 .

[0092] Preferably, all the conductive rods 10 penetrate the front plug 11 .

[0093] Preferably, the conductive rods 10 penetrate the entire length of the front plug 11 along the longitudinal direction . These may ensure mechanical support of the conductive rods 10 . The aerosol-generating article 1 of the first embodiment of the invention may further compri se a conductive element 20 arranged at a tip end of the aerosol-generating article 1 .

[0094] The conductive element 20 defines the second contact portion 8 .

[0095] The conductive element 20 is made of a conductive material . Preferably, the conductive element 20 is made of metal . As an example , the conductive element 20 is made of copper, graphite or nickel .

[0096] Preferably, the conductive element 20 is a disk-shaped element arranged orthogonal to the longitudinal direction . Preferably, the conductive element 20 is arranged in contact with the front plug 11 .

[0097] Preferably, the conductive element 20 is arranged in contact with the conductive rods 10 allowing the electrical connection between the corresponding electrical terminal of the aerosol-generating device and the conductive rods 10 .

[0098] According to a second embodiment of the invention shown in Fig . 2 , analogously to the first embodiment , the first electrode 5 comprises the conductive plate 9 arranged orthogonal to the longitudinal direction at the first end 2 a of the aerosol generating substrate 2 .

[0099] Analogously to the first embodiment , the first contact portion 7 of the aerosol-generating article 1 of the second embodiment may comprise the conductive portion 19 of the cigarette paper 18 impregnated with the conductive ink .

[0100] According to the second embodiment of the invention, the second electrode 8 comprises a conductive plate 12 which is substantially analogous to the conductive plate 9 of the first electrode 5 . Speci fically, the conductive plate 12 of the second electrode 8 is arranged orthogonal to the longitudinal direction at the second end 2b of the aerosol generating substrate 2 .

[0101] Preferably, the conductive plate 12 of the second electrode 8 is arranged between the aerosol-generating substrate 2 and the front plug 11 .

[0102] The conductive plate 12 of the second electrode 6 is made of a conductive material . Preferably, the conductive plate 12 of the second electrode 6 is made of metal . As an example , the conductive plate 12 of the second electrode 6 is made of copper, graphite or nickel .

[0103] Preferably, the conductive plate 12 of the second electrode 6 is disk-shaped . Preferably, the diameter of the conductive plate 12 of the second electrode 6 is substantially the same as that of the aerosol generating substrate 2 measured in a plane orthogonal to the longitudinal direction .

[0104] Alternatively, the conductive plate 12 of the second electrode 6 can have any other proper shape and / or dimension as long as it does not exceed the transversal dimension of the aerosol-generating substrate 2 .

[0105] As can be seen in Fig . 2 , the conductive plate 9 of the first electrode 5 and the conductive plate 12 of the second electrode 6 are arranged parallel to each other and the aerosol-generating substrate 2 is arranged between the conductive plates 9 , 12 .

[0106] The second contact portion 8 of the aerosol-generating article 1 of the second embodiment may comprise a further conductive portion 19 of the cigarette paper 18 impregnated with the conductive ink analogous to the conductive portion 19 defining the first contact portion 7 . According to a modi fication of the second embodiment of the invention, the conductive plate 9 of the first electrode 5 and / or the conductive plate 12 of the second electrode 6 comprises at least a spike 13 extending from the respective conductive plate 9 , 12 towards the opposite one .

[0107] Preferably, the conductive plate 9 of the first electrode 5 and / or the conductive plate 12 of the second electrode 6 comprises a plurality of spikes 13 extending from the respective conductive plate 9 , 12 towards the opposite one .

[0108] Preferably, both the conductive plate 9 of the first electrode 5 and the conductive plate 12 of the second electrode 6 comprises a plurality of spikes 13 extending from the respective conductive plate 9 , 12 towards the opposite one .

[0109] The spikes 13 are made of a conductive material . For example , the spikes 13 are made of copper, graphite or nickel .

[0110] According to a third embodiment of the invention shown in Fig . 3 , the first electrode 5 and the second electrode 6 comprise respective conductive sheets 14 , 15 arranged at a lateral surface of the aerosol generating substrate 2 along the longitudinal direction .

[0111] Each conductive sheet 14 , 15 develops along the longitudinal direction and has a cross-section with reference to the longitudinal direction shaped as a circumferential arc .

[0112] Each conductive sheet 14 , 15 is arranged at opposite positions at a lateral surface of the aerosol generating substrate 2 in such a way to enclose the aerosol generating substrate 2 . The conductive sheets 14 , 15 are arranged such that their rectilinear edges parallel to the longitudinal direction are next to each other . However, the conductive sheets 14 , 15 do not contact each other .

[0113] Preferably, the conductive sheets 14 , 15 have each the same shape and dimension .

[0114] The conductive sheets 14 , 15 are made of a conductive material . For example , the conductive sheets 14 , 15 are made of copper, graphite or nickel .

[0115] The conductive sheets 14 , 15 are connected to the respective first contact portion 7 and second contact portion 8 .

[0116] For example , the first contact portion 7 and the second contact portion 8 may comprise respective conductive portions 19 of the cigarette paper 18 of the impregnated conductive ink .

[0117] According to a modi fication of the third embodiment of the invention, the conductive sheet 14 of the first electrode 5 and / or the conductive sheet 15 of the second electrode 6 comprises at least a spike 13 extending from the respective conductive sheet 14 , 15 towards the opposite one .

[0118] Preferably, the conductive sheet 14 of the first electrode 5 and / or the conductive sheet 15 of the second electrode 6 comprises a plurality of spikes 13 extending from the respective conductive plate 9 , 12 towards the opposite one .

[0119] Preferably, both the conductive sheet 14 of the first electrode 5 and / or the conductive sheet 15 of the second electrode 6 comprise a plurality of spikes 13 extending from the respective conductive plate 9 , 12 towards the opposite one . According to another modi fication of the third embodiment of the invention, the conductive sheet 14 of the first electrode 5 and / or the conductive sheet 15 of the second electrode 6 are microperforated .

[0120] In other words , the conductive sheet 14 of the first electrode 5 and / or the conductive sheet 15 of the second electrode 6 present a plurality o f perforations therethrough which are preferably evenly distributed .

[0121] Due to less usage of materials , this allows a reduction of costs and environmental impact .

[0122] According to a further modi fication of the third embodiment of the invention, the conductive sheet 14 of the first electrode 5 and / or the conductive sheet 15 of the second electrode 6 are microperforated and present the plurality of spikes 13 .

[0123] Comparing with the first and second embodiments , the third embodiment may be beneficial in view of discharging gaseous hydrogen (H2) and / or oxygen ( 02) .

[0124] According to a fourth embodiment of the invention shown in Fig . 4 , the first electrode 5 comprises a first cylindrical sheet 16 arranged at a lateral surface of the aerosol generating substrate 2 along the longitudinal direction .

[0125] Further, the second electrode 6 comprises a second cylindrical sheet 17 having a diameter smaller than the diameter of the first cylindrical sheet 16 and arranged coaxially to the first cylindrical sheet 16 along the longitudinal direction .

[0126] In other words , the first and second cylindrical sheets 16 , 17 are tube-like elements arranged coaxially to each other . The first and second cylindrical sheets 16 , 17 are made of a conductive material . Preferably, the first and second cylindrical sheets 16 , 17 are made of metal . As an example , the first and second cylindrical sheets 16 , 17 are made of copper, graphite or nickel .

[0127] The first and second cylindrical sheets 16 , 17 may have the same length .

[0128] Preferably, the first and second cylindrical sheets 16 , 17 have di f ferent lengths .

[0129] Speci fically, the second cylindrical sheet 17 is longer than the first cylindrical sheet 16 .

[0130] In this case , preferably, the second cylindrical sheet 17 protrudes from the aerosol-generating substrate 2 to penetrate at least in part the front plug 11 .

[0131] Preferably, the second cylindrical sheet 17 penetrates the entire length of the front plug 11 along the longitudinal direction .

[0132] In this case , the aerosol-generating article 1 of the fourth embodiment of the invention may further comprise the conductive element 20 , analogous to that of the first embodiment , arranged at the tip end of the aerosol-generating article 1 .

[0133] The conductive element 20 defines the second contact portion

[0134] The first contact portion 8 of the aerosol-generating article 1 of the fourth embodiment may comprise the conductive portions 19 of the cigarette paper 18 of the impregnated conductive ink . According to a modi fication of the fourth embodiment of the invention, the first cylindrical sheet 16 and / or the second cylindrical sheet 17 comprise at least a spike 13 extending from the respective cylindrical sheet 16 , 17 towards the opposite one .

[0135] Preferably, the first cylindrical sheet 16 and / or the second cylindrical sheet 17 comprise a plurality of spikes 13 extending from the respective cylindrical sheet 16 , 17 towards the opposite one .

[0136] Preferably, both the first cylindrical sheet 16 and / or the second cylindrical sheet 17 comprise a plurality of spikes 13 extending from the respective cylindrical sheet 16 , 17 towards the opposite one .

[0137] According to another modi fication of the fourth embodiment of the invention, first cylindrical sheet 16 and / or the second cylindrical sheet 17 are microperforated .

[0138] In other words , the first cylindrical sheet 16 and / or the second cylindrical sheet 17 present a plurality of perforations therethrough which are preferably evenly distributed .

[0139] Due to less usage of materials , this allows a reduction of costs and environmental impact .

[0140] According to a further modi fication of the fourth embodiment of the invention, the first cylindrical sheet 16 and / or the second cylindrical sheet 17 are microperforated and present the plurality of spikes 13 .

[0141] The fourth embodiment may be also beneficial in view of discharging gaseous hydrogen (H2) and / or oxygen ( 02) , as same as the third embodiment . The invention also provides a method for removing humidity in the described aerosol-generating article 1 .

[0142] As already mentioned, the method comprises a step of generating and applying the electrical field in the aerosol generating substrate 2 through means for generating an electrical field 4 .

[0143] In this way, electrolysis of water contained in the aerosol generating substrate 2 is determined and water i s disassociated in gaseous oxygen and hydrogen which are then removed .

[0144] In particular, the step of generating and applying the electrical field comprises the step of applying a voltage between the first electrode 5 and the second electrode 6 . Such the applied voltage may be boosted battery voltage by converter and so on .

[0145] Preferably, the step of generating and applying the electrical field to the aerosol-generating substrate 2 is performed during a pre-heating step in which the aerosolgenerating article 1 of the invention is introduced in the aerosol-generating device and warmed up .

[0146] In other words , the step of generating and applying the electrical field to the aerosol-generating substrate 2 is performed before the aerosol-generating device is ready to be used by the user and, in particular, before the first puf f of the user has been made .

[0147] Preferably, the method of the invention further comprises a step of j udging a completion of pre-heating and / or removing humidity when a value of the current flowing between the first electrode 5 and the second electrode 6 is below a predetermined threshold value . This allows to evaluate in a precise way when the preliminary operations of the aerosol-generating device are concluded and the step of generating and applying the electrical field can be stopped .

[0148] Naturally, the description set forth herein above concerning embodiments and examples that apply the principles recogni zed by the inventors is provided solely by way of example of these principles and therefore not to be understood as a limitation of the scope of the invention claimed herein . Thus , although detailed embodiments and examples have been described, they only serve to provide a better understanding of the invention defined by the independent claims and are not to be seen as limiting .

Claims

CLAIMS1. An aerosol-generating article (1) comprising: an aerosol-generating substrate (2) extending along a longitudinal direction; a filter portion (3) arranged downstream of the aerosolgenerating substrate (2) and extending along the longitudinal direction; wherein the aerosol-generating substrate (2) presents a first end (2a) proximal to the filter portion (3) and a second end (2b) opposed to the first end (2a) in the longitudinal direction; characterized by means for generating an electrical field (4) arranged at the aerosol-generating substrate (2) to generate electrolysis of water contained in the aerosol generating substrate (2) .

2. The aerosol-generating article (1) according to claim 1, wherein the means for generating an electrical field (4) comprises a first electrode (5) and a second electrode (6) ; wherein the aerosol-generating substrate (2) is arranged at least in part between the first electrode (5) and the second electrode ( 6 ) .

3. The aerosol-generating article (1) according to claim 2, wherein the means for generating an electrical field (4) comprises a first contact portion (7) and a second contact portion (8) , each connected to the corresponding first (5) and second electrode (6) ; the first contact portion (7) and the second contact portion (8) being configured to be applied voltage .

4. The aerosol-generating article (1) according to claim 2 or 3, wherein the first electrode (5) comprises a conductive plate (9) arranged orthogonal to the longitudinal direction at the first end (2a) of the aerosol generating substrate (2) .

5. The aerosol-generating article (1) according to any one of claims 2 to 4, wherein the second electrode (6) comprises at least a conductive rod (10) arranged at the second end (2b) of the aerosol generating substrate (2) .

6. The aerosol-generating article (1) according to claim 5, further comprising a front plug (11) arranged at the second end (2b) of the aerosol generating substrate (2) ; the at least one conductive rod (10) penetrating the front plug (11) •7. The aerosol-generating article (1) according to any one of claims 1 to 3, wherein the first electrode (5) comprises a conductive plate (9) arranged orthogonal to the longitudinal direction at the first end (2a) of the aerosol generating substrate (2) , wherein the second electrode (6) comprises a conductive plate (12) arranged orthogonal to the longitudinal direction at the second end (2b) of the aerosol generating substrate (2) , and the conductive plate (9) of the first electrode (5) and / or the conductive plate (12) of the second electrode (6) comprises at least a spike (13) extending from the respective conductive plate (9, 12) towards the opposite one .

8. The aerosol-generating article (1) according to claim 2 or 3, wherein the first electrode (5) and the second electrode (6) comprise respective conductive sheets (14,15) arranged at a lateral surface of the aerosol generating substrate (2) along the longitudinal direction; and wherein the conductive sheets (14,15) present a cross-section with reference to the longitudinal direction shaped as a circumferential arc so as to cover the aerosol generating substrate ( 2 ) .

9. The aerosol-generating article (1) according to claim 8, wherein the conductive sheets (14,15) comprise a plurality of spikes extending in the aerosol generating substrate (2) .

10. The aerosol-generating article (1) according to claim 2 or 3, wherein the first electrode (5) comprises a first cylindrical sheet (16) arranged at a lateral surface of the aerosol generating substrate (2) along the longitudinal direction; wherein the second electrode (6) comprises a second cylindrical sheet (17) having a diameter smaller than the diameter of the first cylindrical sheet (16) and arranged coaxially to the first cylindrical sheet (16) along the longitudinal direction.

11. The aerosol-generating article (1) according to claim 10, wherein the first cylindrical sheet (16) and / or the second cylindrical sheet (17) comprise a plurality of spikes extending in the aerosol generating substrate (2) .

12. The aerosol-generating article (1) according to claim 10 or claim 11, further comprising a front plug (11) arranged at the second end (2b) of the aerosol generating substrate (2) ; the second cylindrical sheet (17) penetrating the front plug (11) •13. The aerosol-generating article (1) according to any one of claims 3 to 12, further comprising a cigarette paper (18) at least enveloping the aerosol generating substrate (2) ; the first contact portion (7) and / or second contact portion (8) comprising a conductive portion (19) of the cigarette paper (18) impregnated with a conductive ink.

14. A method for removing humidity in an aerosol-generating article (1) , the aerosol-generating article (1) being in accordance with any one of claims 1 to 13, comprising the step of applying an electrical field in the aerosol generating substrate (2) through means for generating anelectrical field (4) to generate electrolysis of water contained in the aerosol generating substrate (2) ; and wherein the step of applying an electrical field in the aerosol generating substrate (2) comprises the step of applying a voltage between the first electrode (5) and the second electrode (6) .

15. A method according to claim 14, further comprising a step of judging a completion of pre-heating and / or removing humidity when a value of current flowing through between the first electrode (5) and the second electrode (6) is below a predetermined threshold value.

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