EP4436412B1 - Aerosol-generating article with an aerosol-generating substrate circumscribed by a high-porosity annular portion - Google Patents

Aerosol-generating article with an aerosol-generating substrate circumscribed by a high-porosity annular portion

Info

Publication number
EP4436412B1
EP4436412B1 EP22818042.8A EP22818042A EP4436412B1 EP 4436412 B1 EP4436412 B1 EP 4436412B1 EP 22818042 A EP22818042 A EP 22818042A EP 4436412 B1 EP4436412 B1 EP 4436412B1
Authority
EP
European Patent Office
Prior art keywords
aerosol
millimetres
generating
generating article
annular portion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP22818042.8A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP4436412C0 (en
EP4436412A1 (en
Inventor
Ricardo CALI
Yiu Chi CHEUNG
Rui Nuno Rodrigues Alves BATISTA
Cheng Peng
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Philip Morris Products SA
Original Assignee
Philip Morris Products SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Philip Morris Products SA filed Critical Philip Morris Products SA
Publication of EP4436412A1 publication Critical patent/EP4436412A1/en
Application granted granted Critical
Publication of EP4436412C0 publication Critical patent/EP4436412C0/en
Publication of EP4436412B1 publication Critical patent/EP4436412B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • A—HUMAN NECESSITIES
    • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24D—CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES OF CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
    • A24D1/00—Cigars; Cigarettes
    • A24D1/20—Cigarettes specially adapted for simulated smoking devices
    • A—HUMAN NECESSITIES
    • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24C—MACHINES FOR MAKING CIGARS OR CIGARETTES
    • A24C5/00—Making cigarettes; Making tipping materials for, or attaching filters or mouthpieces to, cigars or cigarettes
    • A24C5/14—Machines of the continuous-rod type
    • A24C5/18—Forming the rod
    • A24C5/1885—Forming the rod for cigarettes with an axial air duct
    • A—HUMAN NECESSITIES
    • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24D—CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES OF CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
    • A24D1/00—Cigars; Cigarettes
    • A24D1/02—Cigars; Cigarettes with special covers
    • A—HUMAN NECESSITIES
    • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24D—CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES OF CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
    • A24D3/00—Tobacco smoke filters, e.g. filter tips or filtering inserts; Filters specially adapted for simulated smoking devices; Mouthpieces of cigars or cigarettes
    • A24D3/02—Manufacture of tobacco smoke filters
    • A24D3/0275—Manufacture of tobacco smoke filters for filters with special features
    • A24D3/0279—Manufacture of tobacco smoke filters for filters with special features with tubes
    • A—HUMAN NECESSITIES
    • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24D—CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES OF CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
    • A24D3/00—Tobacco smoke filters, e.g. filter tips or filtering inserts; Filters specially adapted for simulated smoking devices; Mouthpieces of cigars or cigarettes
    • A24D3/06—Use of materials for tobacco smoke filters
    • A24D3/062—Use of materials for tobacco smoke filters characterised by structural features
    • A24D3/063—Use of materials for tobacco smoke filters characterised by structural features of the fibers
    • A—HUMAN NECESSITIES
    • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24F—SMOKERS' REQUISITES; MATCH BOXES; SIMULATED SMOKING DEVICES
    • A24F40/00—Electrically operated smoking devices; Component parts thereof; Manufacture thereof; Maintenance or testing thereof; Charging means specially adapted therefor
    • A24F40/20—Devices using solid inhalable precursors
    • A—HUMAN NECESSITIES
    • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24F—SMOKERS' REQUISITES; MATCH BOXES; SIMULATED SMOKING DEVICES
    • A24F40/00—Electrically operated smoking devices; Component parts thereof; Manufacture thereof; Maintenance or testing thereof; Charging means specially adapted therefor
    • A24F40/40—Constructional details, e.g. connection of cartridges and battery parts
    • A24F40/48—Fluid transfer means, e.g. pumps
    • A24F40/485—Valves; Apertures
    • A—HUMAN NECESSITIES
    • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24D—CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES OF CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
    • A24D3/00—Tobacco smoke filters, e.g. filter tips or filtering inserts; Filters specially adapted for simulated smoking devices; Mouthpieces of cigars or cigarettes
    • A24D3/17—Filters specially adapted for simulated smoking devices
    • A—HUMAN NECESSITIES
    • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24F—SMOKERS' REQUISITES; MATCH BOXES; SIMULATED SMOKING DEVICES
    • A24F40/00—Electrically operated smoking devices; Component parts thereof; Manufacture thereof; Maintenance or testing thereof; Charging means specially adapted therefor
    • A24F40/40—Constructional details, e.g. connection of cartridges and battery parts
    • A24F40/46—Shape or structure of electric heating means
    • A24F40/465—Shape or structure of electric heating means specially adapted for induction heating

Definitions

  • the present invention relates to an aerosol-generating article comprising an aerosol-generating substrate and adapted to produce an inhalable aerosol upon heating.
  • Aerosol-generating articles in which an aerosol-generating substrate, such as a tobacco-containing substrate, is heated rather than combusted, are known in the art.
  • an aerosol is generated by the transfer of heat from a heat source to a physically separate aerosol-generating substrate or material, which may be located in contact with, within, around, or downstream of the heat source.
  • volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source and are entrained in air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol.
  • a number of prior art documents disclose aerosol-generating devices for consuming aerosol-generating articles.
  • Such devices include, for example, electrically heated aerosol-generating devices in which an aerosol is generated by the transfer of heat from one or more electrical heater elements of the aerosol-generating device to the aerosol-generating substrate of a heated aerosol-generating article.
  • electrically heated aerosol-generating devices have been proposed that comprise an internal heater blade which is adapted to be inserted into the aerosol-generating substrate.
  • inductively heatable aerosol-generating articles comprising an aerosol-generating substrate and a susceptor arranged within the aerosol-generating substrate have been proposed by WO 2015/176898 .
  • WO 2020/115151 discloses an aerosol-generating article used in combination with an external heating system comprising one or more heating elements arranged around the periphery of the aerosol-generating article.
  • external heating elements may be provided in the form of flexible heating foils on a dielectric substrate, such as polyimide.
  • WO 2021/180967 describes an example of an aerosol-generating article suitable for use with a heating device.
  • the aerosol-generating article comprises a rod of aerosol-forming substrate circumscribed by a porous wrapper.
  • Another example of an aerosol-generating article suitable for use with a heating device is known from WO 2021/180968 .
  • WO 2016/023965 discloses methods of making rods for use as aerosol-forming substrates in aerosol-generating articles, the methods aiming at controlling the porosity and porosity distribution of the rods.
  • WO 2020/127116 describes a tubular element for use with an aerosol generating article, wherein the tubular element comprises a porous medium loaded with a gel.
  • Aerosol-generating articles in which a tobacco-containing substrate is heated rather than combusted present a number of challenges that were not encountered with conventional smoking articles.
  • tobacco-containing substrates are typically heated to significantly lower temperatures compared with the temperatures reached by the combustion front in a conventional cigarette. This may have an impact on nicotine release from the tobacco-containing substrate and nicotine delivery to the consumer. Additionally, it may be difficult to heat homogenously the entirety of the tobacco-containing substrate provided within the article.
  • Difficulties in transferring heat efficiently may lead to portions of the rod of aerosol-generating substrate being unable to reach a temperature sufficient to promote release of aerosol species.
  • those portions of the rod of aerosol-generating substrate may not substantially contribute to the overall aerosol delivery of the aerosol-generating article, and so an efficiency of use of the aerosol-generating substrate provided in the rod may undesirably be less than ideal.
  • Difficulties in transferring heat efficiently may also lead to portions of the rod of aerosol-generating substrate wherein a temperature sufficient to promote release of aerosol species is indeed reached, but only over a small fraction of the use cycle of the aerosol-generating article.
  • a temperature profile during use may differ from an intended temperature profile, and so the aerosol-generating substrate may undesirably be underutilised.
  • an aerosol-generating article may potentially be heated in any aerosol-generating device available on the market provided that it is compatible with the size - namely, the diameter - of the aerosol-generating article, irrespective of whether the aerosol-generating article and that specific model of aerosol-generating device have been devised to be used together or not.
  • One such potential mismatch of aerosol-generating article and device may lead to the aerosol-generating substrate being exposed to a non-optimised temperature profile, possibly in combination with a non-ideal airflow mechanism through the system during use. This may unfavourably impact aerosol delivery and temperatures, and generally alter the system's conditions of use relative to the intended ones.
  • the present invention relates to an aerosol-generating article as set forth in claim 1, for producing an inhalable aerosol upon heating.
  • the aerosol-generating article comprises an aerosol-generating rod extending from an upstream end to a downstream end.
  • the aerosol-generating article further comprises a downstream section provided downstream of the aerosol-generating rod. The downstream section abuts the downstream end of the aerosol-generating rod.
  • the aerosol-generating rod comprises a substantially cylindrical core portion having a longitudinal axis and an annular portion surrounding and extending coaxially with the core portion.
  • the annular portion is air permeable.
  • the annular portion is in fluid communication with the downstream section.
  • the annular portion may be in direct fluid communication with the downstream section.
  • the core portion comprises an aerosol-generating substrate.
  • the core portion has a cross-sectional porosity of from 0.10 to 0.45.
  • a cross-sectional porosity of the annular portion is at least 120 percent of the cross-sectional porosity of the core portion.
  • a thickness of the annular portion is at least 0.5 millimetres.
  • an aerosol-generating system as set forth in claim 15 comprising an aerosol-generating article as described above and an aerosol-generating device.
  • the aerosol-generating device comprises a heating chamber open at a proximal end to at least partly receive the aerosol-generating rod to heat the aerosol-generating substrate.
  • the aerosol-generating device comprises an opening at a distal end to admit airflow into the heating chamber along a longitudinal axis of the heating chamber. A diameter of the opening is smaller than the internal diameter of the annular portion.
  • the aerosol-generating article according to the present invention therefore provides a novel configuration of the section of the aerosol-generating article configured to generate an aerosol when heated.
  • a substantially cylindrical core portion is provided that contains an aerosol-generating substrate and is circumscribed by an air permeable annular portion having a comparatively higher cross-sectional porosity.
  • the annular portion is sized such that direct fluid communication may be established between the annular portion and the downstream section.
  • a resistance to draw (RTD) of the annular portion is substantially lower than an RTD of the core portion.
  • RTD resistance to draw
  • the aerosol-generating substrate is concentrated at the core of the aerosol-generating rod, in systems wherein heat is supplied to the aerosol-generating article internally - as will be discussed in more detail below - a homogeneous supply of heat to all of the aerosol-generating substrate during use may advantageously be facilitated.
  • the annular portion circumscribing the core portion is not meant to contribute to aerosol generation, supply of heat to the annular portion is not at all crucial.
  • the fact that air permeable annular portion is likely to be heated less in systems wherein heat is supplied to the aerosol-generating article internally may even be beneficial, as in certain embodiments the annular portion may, to an extent, work as a thermally insulating sleeve.
  • the core portion and the annular portion may be dimensioned such that the aerosol-generating article is only compatible for use with an aerosol-generating device having a specific design, such that, when the aerosol-generating article is coupled with the aerosol-generating device, an upstream end of the annular portion becomes occluded while, at the same time, airflow into the core portion is enabled.
  • the aerosol-generating article is coupled with the wrong aerosol-generating device, an upstream end of the core portion becomes at least partly occluded while, at the same time, airflow into the annular portion is enabled, which makes use of the aerosol-generating article virtually impossible.
  • an opening may be provided at a distal end of the aerosol-generating device to enable flow of air into a heating chamber into which the aerosol-generating article is received.
  • an aerosol-generating article for generating an inhalable aerosol upon heating.
  • the aerosol-generating article comprises an aerosol-generating rod that extends from an upstream end to a downstream end.
  • a core portion of the aerosol-generating rod comprises an aerosol-generating substrate.
  • aerosol generating article is used herein to denote an article wherein an aerosol generating substrate is heated to produce and deliver inhalable aerosol to a consumer.
  • aerosol generating substrate denotes a substrate capable of releasing volatile compounds upon heating to generate an aerosol.
  • a conventional cigarette is lit when a user applies a flame to one end of the cigarette and draws air through the other end.
  • the localised heat provided by the flame and the oxygen in the air drawn through the cigarette causes the end of the cigarette to ignite, and the resulting combustion generates an inhalable smoke.
  • an aerosol is generated by heating a flavour generating substrate, such as tobacco.
  • Known heated aerosol generating articles include, for example, electrically heated aerosol generating articles and aerosol generating articles in which an aerosol is generated by the transfer of heat from a combustible fuel element or heat source to a physically separate aerosol forming material.
  • aerosol generating articles according to the invention find particular application in aerosol generating systems comprising an electrically heated aerosol generating device having an internal heater blade which is adapted to be inserted into the rod of aerosol generating substrate.
  • Aerosol generating articles of this type are described in the prior art, for example, in EP 0822670 .
  • aerosol generating device refers to a device comprising a heater element that interacts with the aerosol generating substrate of the aerosol generating article to generate an aerosol.
  • rod is used to denote a generally cylindrical element of substantially circular, oval or elliptical cross-section.
  • the term “longitudinal” refers to the direction corresponding to the main longitudinal axis of the aerosol-generating article, which extends between the upstream and downstream ends of the aerosol-generating article.
  • the terms “upstream” and “downstream” describe the relative positions of elements, or portions of elements, of the aerosol-generating article in relation to the direction in which the aerosol is transported through the aerosol-generating article during use.
  • transverse refers to the direction that is perpendicular to the longitudinal axis. Any reference to the "cross-section" of the aerosol-generating article or a component of the aerosol-generating article refers to the transverse cross-section unless stated otherwise.
  • length denotes the dimension of a component of the aerosol-generating article in the longitudinal direction.
  • length may be used to denote the dimension of the rod or of the elongate tubular elements in the longitudinal direction.
  • the aerosol-generating article further comprises a downstream section at a location downstream of the aerosol-generating rod.
  • the downstream section may comprise one or more downstream elements.
  • the downstream section may comprise a hollow section between the mouth end of the aerosol-generating article and the aerosol-generating rod.
  • the hollow section may comprise a hollow tubular element.
  • the term “hollow tubular segment” or “hollow tubular element” is used to denote a generally elongate element defining a lumen or airflow passage along a longitudinal axis thereof.
  • tubular will be used in the following with reference to an element or segment having a substantially cylindrical cross-section and defining at least one airflow conduit establishing an uninterrupted fluid communication between an upstream end of the tubular element or segment and a downstream end of the tubular element or segment.
  • alternative geometries for example, alternative cross-sectional shapes
  • a hollow tubular segment or hollow tubular element provides an unrestricted flow channel.
  • the hollow tubular segment or hollow tubular element provides a negligible level of resistance to draw (RTD).
  • RTD resistance to draw
  • the term "negligible level of RTD” is used to describe an RTD of less than 1 mm H 2 O per 10 millimetres of length of the hollow tubular segment or hollow tubular element, preferably less than 0.4 mm H 2 O per 10 millimetres of length of the hollow tubular segment or hollow tubular element, more preferably less than 0.1 mm H 2 O per 10 millimetres of length of the hollow tubular segment or hollow tubular element.
  • a “hollow tubular segment” or “hollow tubular element” may also be referred to as a “hollow tube” or a “hollow tube segment”.
  • the term “porosity” refers to a fraction of void space in an air permeable or porous body.
  • porosity is used herein with reference to the "cross-sectional porosity" of one such body, that is, the fraction of void space in a cross-sectional area of the air permeable or porous body, for example a cross-section of the cylindrical core portion of the aerosol-generating rod in an aerosol-generating article in accordance with the present invention.
  • the cross-sectional porosity is the area fraction of void space in a transverse cross-sectional area of the cylindrical core portion.
  • the transverse cross-sectional area of the cylindrical core portion is the area of the cylindrical core portion in a plane that is perpendicular to the longitudinal axis of the aerosol-generating rod.
  • the transverse cross-sectional area will be substantially circular.
  • Each sub-area is preferably rectangular or square. It is preferred that a sub-area overlaps at least 50 percent of the transverse cross-sectional area before it is included in the calculation of porosity distribution, particularly preferably at least 70 percent or at least 80 percent or at least 90 percent of the transverse cross-sectional area before it is included in the calculation of porosity distribution.
  • a high cross-sectional porosity distribution value may be an indication that a cylindrical body has a small number of relatively large through-channels, whereas a low cross-sectional porosity distribution value may indicate that a cylindrical body has a high number of relatively small through-channels.
  • the core portion is substantially cylindrical and has an average diameter, for example an average diameter of about 4.5 mm.
  • each of the sub-areas is a rectangle or square having a length of between a quarter and an eighth of the diameter of the core portion, preferably about a sixth or a seventh of the diameter of the core portion.
  • the sub-areas may be squares having sides of about 0.75 mm in length.
  • the porosity value of any individual sub-area is preferably only included in the calculation for evaluating porosity distribution if more than 90 percent of that sub-area is within the transverse cross-sectional area of the core portion.
  • the digital image of the transverse cross-sectional area consists of a plurality of pixels, and every pixel making up the transverse cross-sectional area is contained within at least one of the plurality of sub-areas.
  • the core portion has a cross-sectional porosity of at least 0.15. More preferably, in aerosol-generating articles in accordance with the present invention the core portion has a cross-sectional porosity of at least 0.20.
  • the core portion has a cross-sectional porosity of less than or equal to 0.40. More preferably, the core portion has a cross-sectional porosity of less than or equal to 0.35. Even more preferably, the core portion has a cross-sectional porosity of less than or equal to 0.25.
  • the core portion has a cross-sectional porosity from 0.15 to 0.40, preferably from 0.15 to 0.35, more preferably from 0.15 to 0.25. In other embodiments, the core portion has a cross-sectional porosity from 0.20 to 0.40, preferably from 0.20 to 0.35, more preferably from 0.20 to 0.25.
  • the core portion may have a cross-sectional porosity distribution value of at least 0.04, as calculated using the method described above in which each sub-area is a square having a side length of one seventh of the core portion diameter and in which each sub-area overlaps at least one other sub-area by about 80 percent.
  • the core portion may have a cross-sectional porosity distribution value of at least 0.10, as calculated using the method described above in which each sub-area is a square having a side length of one seventh of the core portion diameter and in which each sub-area overlaps at least one other sub-area by about 80 percent.
  • the core portion may have a cross-sectional porosity distribution value of less than or equal to 0.22, as calculated using the method described above in which each sub-area is a square having a side length of one seventh of the core portion diameter and in which each sub-area overlaps at least one other sub-area by about 80 percent.
  • the core portion may have a cross-sectional porosity distribution value of less than or equal to 0.20, as calculated using the method described above in which each sub-area is a square having a side length of one seventh of the core portion diameter and in which each sub-area overlaps at least one other sub-area by about 80 percent.
  • the core portion may have a cross-sectional porosity distribution value of less than or equal to 0.15, as calculated using the method described above in which each sub-area is a square having a side length of one seventh of the core portion diameter and in which each sub-area overlaps at least one other sub-area by about 80 percent.
  • the core portion may have a cross-sectional porosity distribution value from 0.04 to 0.22, preferably from 0.04 to 0.20, more preferably from 0.04 to 0.15. In other embodiments, the core portion may have a cross-sectional porosity distribution value from 0.10 to 0.22, preferably from 0.10 to 0.20, more preferably from 0.10 to 0.15.
  • an outer diameter of the cylindrical core portion may be at least 1 millimetre. Preferably, an outer diameter of the core portion is at least 3 millimetres. More preferably, an outer diameter of the core portion is at least 3.5 millimetres. An outer diameter of the core portion is preferably less than 8 millimetres. More preferably, an outer diameter of the core portion is less than 7 millimetres. Even more preferably, outer diameter of the core portion is less than 5.75 millimetres.
  • an outer diameter of the core portion is from 3 millimetres to 8 millimetres, preferably from 3 millimetres to 7 millimetres, more preferably from 3 millimetres to 5.75 millimetres. In other embodiments, an outer diameter of the core portion is from 3.5 millimetres to 8 millimetres, preferably from 3.5 millimetres to 7 millimetres, more preferably from 3.5 millimetres to 5.75 millimetres.
  • a density of the aerosol-generating substrate is at least about 150 mg per cubic centimetre. More preferably, a density of the aerosol-generating substrate is at least about 175 mg per cubic centimetre. More preferably, a density of the aerosol-generating substrate is at least about 200 mg per cubic centimetre. Even more preferably, a density of the aerosol-generating substrate is at least about 250 mg per cubic centimetre. Even more preferably, a density of the aerosol-generating substrate is at least about 300, 400, 500 mg per cubic centimetre. Preferably, a density of the aerosol-generating substrate is less than or equal to about 1500 mg per cubic centimetre.
  • a density of the aerosol-generating substrate is less than or equal to about 1000 mg per cubic centimetre. More preferably, a density of the aerosol-generating substrate is less than or equal to about 800 mg per cubic centimetre. Even more preferably, a density of the aerosol-generating substrate is less than or equal to about 700 mg per cubic centimetre.
  • a density of the aerosol-generating substrate is preferably from about 150 mg per cubic centimetre to about 1500 mg per cubic centimetre, preferably from about 175 mg per cubic centimetre to about 450 mg per cubic centimetre, more preferably from about 200 mg per cubic centimetre to about 400 mg per cubic centimetre, even more preferably from 250 mg per cubic centimetre to 350 mg per cubic centimetre.
  • a density of the aerosol-generating substrate is about 300 mg per cubic centimetre.
  • the aerosol-generating substrate in the core portion comprises shredded tobacco material, for example tobacco cut filler, having a density of between about 150 mg per cubic centimetre and about 500 mg per cubic centimetre, preferably between about 175 mg per cubic centimetre and about 450 mg per cubic centimetre, more preferably between about 200 mg per cubic centimetre and about 400 mg per cubic centimetre, more preferably between about 250 mg per cubic centimetre and about 350 mg per cubic centimetre, most preferably about 300 mg per cubic centimetre.
  • tobacco material for example tobacco cut filler
  • the aerosol-generating substrate may be a solid aerosol-generating substrate.
  • the aerosol-generating substrate preferably comprises an aerosol former.
  • the aerosol former may be any suitable known compound or mixture of compounds that, in use, facilitates formation of a dense and stable aerosol.
  • the aerosol former may be facilitating that the aerosol is substantially resistant to thermal degradation at temperatures typically applied during use of the aerosol-generating article.
  • Suitable aerosol formers are for example: polyhydric alcohols such as, for example, triethylene glycol, 1,3-butanediol, propylene glycol and glycerine; esters of polyhydric alcohols such as, for example, glycerol mono-, di- or triacetate; aliphatic esters of mono-, di- or polycarboxylic acids such as, for example, dimethyl dodecanedioate and dimethyl tetradecanedioate; and combinations thereof.
  • polyhydric alcohols such as, for example, triethylene glycol, 1,3-butanediol, propylene glycol and glycerine
  • esters of polyhydric alcohols such as, for example, glycerol mono-, di- or triacetate
  • aliphatic esters of mono-, di- or polycarboxylic acids such as, for example, dimethyl dodecanedioate and dimethyl tetradecanedioate; and combinations
  • the aerosol former comprises one or more of glycerine and propylene glycol.
  • the aerosol former may consist of glycerine or propylene glycol or of a combination of glycerine and propylene glycol.
  • the aerosol-generating substrate comprises at least 5 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate, more preferably between 10 percent and 22 percent by weight on a dry weight basis of the cut aerosol-generating substrate, more preferably, the amount of aerosol former is between 12 percent and 19 percent by weight on a dry weight basis of the aerosol-generating substrate, most for example the amount of aerosol former is between 13 percent and 16 percent by weight on a dry weight basis of the aerosol-generating substrate.
  • the aerosol-generating substrate comprises shredded tobacco material.
  • the shredded tobacco material may be in the form of cut filler, as described in more detail below.
  • the shredded tobacco material may be in the form of a shredded sheet of homogenised tobacco material. Suitable homogenised tobacco materials for use in the present invention are described below.
  • cut filler is used to describe to a blend of shredded plant material, such as tobacco plant material, including, in particular, one or more of leaf lamina, processed stems and ribs, homogenised plant material.
  • the cut filler may also comprise other after-cut, filler tobacco or casing.
  • the cut filler comprises at least 25 percent of plant leaf lamina, more preferably, at least 50 percent of plant leaf lamina, still more preferably at least 75 percent of plant leaf lamina and most preferably at least 90 percent of plant leaf lamina.
  • the plant material is one of tobacco, mint, tea and cloves. Most preferably, the plant material is tobacco.
  • the invention is equally applicable to other plant material that has the ability to release substances upon the application of heat that can subsequently form an aerosol.
  • the cut filler comprises tobacco plant material comprising lamina of one or more of bright tobacco, dark tobacco, aromatic tobacco and filler tobacco.
  • tobacco describes any plant member of the genus Nicotiana. Bright tobaccos are tobaccos with a generally large, light coloured leaves. Throughout the specification, the term “bright tobacco” is used for tobaccos that have been flue cured. Examples for bright tobaccos are Chinese Flue-Cured, Flue-Cured Brazil, US Flue-Cured such as Virginia tobacco, Indian Flue-Cured, Flue-Cured from Africa or other African Flue Cured. Bright tobacco is characterized by a high sugar to nitrogen ratio.
  • bright tobacco is a tobacco type which, after curing, is associated with a spicy and lively sensation.
  • bright tobaccos are tobaccos with a content of reducing sugars of between about 2.5 percent and about 20 percent of dry weight base of the leaf and a total ammonia content of less than about 0.12 percent of dry weight base of the leaf.
  • Reducing sugars comprise for example glucose or fructose.
  • Total ammonia comprises for example ammonia and ammonia salts.
  • dark tobaccos are tobaccos with a generally large, dark coloured leaves. Throughout the specification, the term "dark tobacco” is used for tobaccos that have been air cured. Additionally, dark tobaccos may be fermented. Tobaccos that are used mainly for chewing, snuff, cigar, and pipe blends are also included in this category. Typically, these dark tobaccos are air cured and possibly fermented. From a sensorial perspective, dark tobacco is a tobacco type which, after curing, is associated with a smoky, dark cigar type sensation. Dark tobacco is characterized by a low sugar to nitrogen ratio. Examples for dark tobacco are Burley Malawi or other African Burley, Dark Cured Brazil Galpao, Sun Cured or Air Cured Indonesian Kasturi. According to the invention, dark tobaccos are tobaccos with a content of reducing sugars of less than about 5 percent of dry weight base of the leaf and a total ammonia content of up to about 0.5 percent of dry weight base of the leaf.
  • Aromatic tobaccos are tobaccos that often have small, light coloured leaves. Throughout the specification, the term "aromatic tobacco” is used for other tobaccos that have a high aromatic content, e.g. of essential oils. From a sensorial perspective, aromatic tobacco is a tobacco type which, after curing, is associated with spicy and aromatic sensation.
  • aromatic tobaccos are Greek Oriental, Oriental Turkey, semi-oriental tobacco but also Fire Cured, US Burley, such as Perique, Rustica, US Burley or Meriland.
  • Filler tobacco is not a specific tobacco type, but it includes tobacco types which are mostly used to complement the other tobacco types used in the blend and do not bring a specific characteristic aroma direction to the final product. Examples for filler tobaccos are stems, midrib or stalks of other tobacco types. A specific example may be flue cured stems of Flue Cure Brazil lower stalk.
  • the cut filler suitable to be used with the present invention generally may resemble cut filler used for conventional smoking articles.
  • the cut width of the cut filler preferably is between 0.3 millimetres and 2.0 millimetres, more preferably, the cut width of the cut filler is between 0.5 millimetres and 1.2 millimetres and most preferably, the cut width of the cut filler is between 0.6 millimetres and 0.9 millimetres.
  • the cut width may play a role in the distribution of heat inside the rod of aerosol-generating substrate. Also, the cut width may play a role in the resistance to draw of the core portion. Further, the cut width may impact the overall density and cross-sectional porosity of the core portion as a whole.
  • the strand length of the cut-filler is to some extent a random value as the length of the strands will depend on the overall size of the object that the strand is cut off from. Nevertheless, by conditioning the material before cutting, for example by controlling the moisture content and the overall subtlety of the material, longer strands can be cut.
  • the strands Preferably, have a length of between about 10 millimetres and about 40 millimetres before the strands are collated to form the rod of aerosol-generating substrate.
  • the final core portion of aerosol-generating substrate may comprise strands that are on average shorter than the initial strand length.
  • the strand length of the cut-filler is such that between about 20 percent and 60 percent of the strands extend along the full length of the rod of aerosol-generating substrate. This prevents the strands from dislodging easily from the rod of aerosol-generating substrate.
  • the weight of the cut filler is between 80 milligrams and 400 milligrams, preferably between 150 milligrams and 250 milligrams, more preferably between 170 milligrams and 220 milligrams.
  • This amount of cut filler typically allows for sufficient material for the formation of an aerosol. Additionally, in the light of the aforementioned constraints on diameter and size, this allows for a balanced density of the core portion comprising the aerosol-generating substrate between energy uptake, resistance to draw and fluid passageways within the rod of aerosol-generating substrate where the aerosol-generating substrate comprises plant material.
  • the cut filler is soaked with aerosol former. Soaking the cut filler can be done by spraying or by other suitable application methods.
  • the aerosol former may be applied to the blend during preparation of the cut filler.
  • the aerosol former may be applied to the blend in the direct conditioning casing cylinder (DCCC).
  • DCCC direct conditioning casing cylinder
  • Conventional machinery can be used for applying an aerosol former to the cut filler.
  • the aerosol former may be any suitable known compound or mixture of compounds that, in use, facilitates formation of a dense and stable aerosol.
  • the aerosol former may be facilitating that the aerosol is substantially resistant to thermal degradation at temperatures typically applied during use of the aerosol-generating article.
  • Suitable aerosol formers are for example to: polyhydric alcohols such as, for example, triethylene glycol, 1,3-butanediol, propylene glycol and glycerine; esters of polyhydric alcohols such as, for example, glycerol mono-, di- or triacetate; aliphatic esters of mono-, di- or polycarboxylic acids such as, for example, dimethyl dodecanedioate and dimethyl tetradecanedioate; and combinations thereof.
  • polyhydric alcohols such as, for example, triethylene glycol, 1,3-butanediol, propylene glycol and glycerine
  • esters of polyhydric alcohols such as, for example, glycerol mono-, di- or triacetate
  • aliphatic esters of mono-, di- or polycarboxylic acids such as, for example, dimethyl dodecanedioate and dimethyl tetradecanedioate
  • the aerosol former comprises one or more of glycerine and propylene glycol.
  • the aerosol former may consist of glycerine or propylene glycol or of a combination of glycerine and propylene glycol.
  • the amount of aerosol former is at least 5 percent by weight on a dry weight basis, preferably between 10 percent and 22 percent by weight on a dry weight basis of the cut filler, more preferably, the amount of aerosol former is between 12 percent and 19 percent by weight on a dry weight basis of the cut filler, for example the amount of aerosol former is between 13 percent and 16 percent by weight on a dry weight basis of the cut filler.
  • the cut filler may become relatively sticky.
  • the amount of aerosol former has a target value of about 13 percent by weight on a dry weight basis of the cut filler.
  • the most efficient amount of aerosol former will depend also on the cut filler, whether the cut filler comprises plant lamina or homogenized plant material. For example, among other factors, the type of cut filler will determine to which extent the aerosol-former can facilitate the release of substances from the cut filler.
  • a core portion comprising cut filler as described above as the aerosol-generating substrate is capable of efficiently generating sufficient amount of aerosol at relatively low temperatures.
  • a temperature of between 150 degrees Celsius and 200 degrees Celsius in the heating chamber may be sufficient for one such cut filler to generate sufficient amounts of aerosol while in aerosol-generating devices using tobacco cast leave sheets typically temperatures of about 250 degrees Celsius are employed.
  • a further advantage connected with operating at lower temperatures is that there is a reduced need to cool down the aerosol. As generally low temperatures are used, a simpler cooling function may be sufficient. This in turn allows using a simpler and less complex structure of the aerosol-generating article.
  • the aerosol-generating substrate comprises homogenised plant material, preferably a homogenised tobacco material.
  • homogenised plant material encompasses any plant material formed by the agglomeration of particles of plant.
  • sheets or webs of homogenised tobacco material for the aerosol-generating substrates of the present invention may be formed by agglomerating particles of tobacco material obtained by pulverising, grinding or comminuting plant material and optionally one or more of tobacco leaf lamina and tobacco leaf stems.
  • the homogenised plant material may be produced by casting, extrusion, paper making processes or other any other suitable processes known in the art.
  • the homogenised plant material can be provided in any suitable form.
  • the homogenised plant material may be in the form of one or more sheets.
  • sheet describes a laminar element having a width and length substantially greater than the thickness thereof.
  • the homogenised plant material may be in the form of a plurality of pellets or granules.
  • the sheets may be produced by a casting process.
  • sheets of homogenised plant material may be produced by a paper-making process.
  • the strip or blade preferably has a rectangular shape having a width of preferably from 2 millimetres to 6 millimetres, more preferably from 2.5 millimetres to 5.5 millimetres, even more preferably from 3 millimetres to 5 millimetres.
  • a susceptor in the form of a strip of blade may have a width of about 3.75 millimetres.
  • a cross-sectional porosity of the annular portion may be from 130 percent to 600 percent of the cross-sectional porosity of the core portion or from 130 percent to 500 percent of the cross-sectional porosity of the core portion or from 130 percent to 400 percent of the cross-sectional porosity of the core portion or from 130 percent to 300 percent of the cross-sectional porosity of the core portion or from 130 percent to 200 percent of the cross-sectional porosity of the core portion.
  • a cross-sectional porosity of the annular portion may be from 140 percent to 600 percent of the cross-sectional porosity of the core portion or from 140 percent to 500 percent of the cross-sectional porosity of the core portion or from 140 percent to 400 percent of the cross-sectional porosity of the core portion or from 140 percent to 300 percent of the cross-sectional porosity of the core portion or from 140 percent to 200 percent of the cross-sectional porosity of the core portion.
  • a cross-sectional porosity of the annular portion may be from 150 percent to 600 percent of the cross-sectional porosity of the core portion or from 150 percent to 500 percent of the cross-sectional porosity of the core portion or from 150 percent to 400 percent of the cross-sectional porosity of the core portion or from 150 percent to 300 percent of the cross-sectional porosity of the core portion or from 150 percent to 200 percent of the cross-sectional porosity of the core portion.
  • a cross-sectional porosity of the annular portion may be up to 0.99.
  • a cross-section porosity of the annular portion is less than 0.95. More preferably, a cross-section porosity of the annular portion is less than 0.90. Even more preferably, a cross-section porosity of the annular portion is less than 0.85. This is beneficial in that it may ensure a certain structural strength of the annular portion and of the rod as a whole.
  • a cross-sectional porosity of the annular portion may be at least 0.3.
  • a cross-sectional porosity of the annular portion is at least 0.35. More preferably, a cross-sectional porosity of the annular portion is at least 0.4. Even more preferably, a cross-sectional porosity of the annular portion is at least 0.45.
  • a cross-sectional porosity of the annular portion is from 0.3 to 0.95, preferably from 0.35 to 0.95, more preferably from 0.4 to 0.95, even more preferably from 0.5 to 0.95.
  • a cross-sectional porosity of the annular portion is from 0.3 to 0.90, preferably from 0.35 to 0.90, more preferably from 0.4 to 0.90, even more preferably from 0.5 to 0.90.
  • a cross-sectional porosity of the annular portion is from 0.3 to 0.85, preferably from 0.35 to 0.85, more preferably from 0.4 to 0.85, even more preferably from 0.5 to 0.85.
  • the annular portion presents a resistance to draw (RTD) that is significantly lower than an RTD of the core portion.
  • RTD resistance to draw
  • an RTD of the annular portion is preferably less than 65 millimetres H 2 O. More preferably, an RTD of the annular portion is preferably less than 60 millimetres H 2 O. Even more preferably, an RTD of the annular portion is preferably less than 55 millimetres H 2 O.
  • An RTD of the annular portion may be at least 5 millimetres H 2 O.
  • an RTD of the annular portion is at least 10 millimetres H 2 O. More preferably, an RTD of the annular portion is at least 20 millimetres H 2 O. Even more preferably, an RTD of the annular portion is at least 30 millimetres H 2 O.
  • an RTD of the annular portion is from 10 millimetres H 2 O to 65 millimetres H 2 O, preferably from 10 millimetres H 2 O to 60 millimetres H 2 O, more preferably from 10 millimetres H 2 O to 55 millimetres H 2 O. In other embodiments, an RTD of the annular portion is from 20 millimetres H 2 O to 65 millimetres H 2 O, preferably from 20 millimetres H 2 O to 60 millimetres H 2 O, more preferably from 20 millimetres H 2 O to 55 millimetres H 2 O.
  • an RTD of the annular portion is from 30 millimetres H 2 O to 65 millimetres H 2 O, preferably from 30 millimetres H 2 O to 60 millimetres H 2 O, more preferably from 30 millimetres H 2 O to 55 millimetres H 2 O.
  • the annular portion may comprise a porous material, such as for example a foam or a fibrous material, such as a non-woven material.
  • the annular portion may comprise a fibrous material.
  • the annular portion comprises a plurality of fibres, preferably linear and axially oriented fibres.
  • the expression "linear and axially oriented fibres” is used to describe a plurality of fibres that are substantially aligned with one another along an axial direction, or aerosol draw direction, of the annular portion. This is in contrast to multidirectional or random or multidirectional and random oriented fibres, that is, in contrast to a plurality of fibres which are predominantly misaligned, having a plurality of different or random or different and random orientations, including both parallel and perpendicular with respect to the axial or aerosol draw direction.
  • the annular portion comprises fibres selected from: cellulose acetate fibres, poly lactic acid (PLA) fibres, polypropylene fibres, poly(3-hydroxybutyrate-co-hydroxyvalerate)(PHVB) fibres, rayon fibres, viscose fibres, regenerated cellulose fibres, and combinations thereof.
  • PLA poly lactic acid
  • PHVB poly(3-hydroxybutyrate-co-hydroxyvalerate)
  • the annular portion may comprise two or more longitudinal segments of tow material, and the tow material of adjacent ones of the two or more longitudinal segments is bonded together at least along longitudinal edges of the segments to form an integral annular portion. At least two or all of the segments may be formed from the same tow.
  • the annular portion comprises fibres having a denier per filament (dpf) of at least 3.0. More preferably, the annular portion comprises fibres having a dpf of at least 5.0. More preferably, the annular portion comprises fibres having a dpf of at least 6.0.
  • dpf denier per filament
  • the annular portion comprises fibres having a dpf of less than or equal to 15.0. More preferably, the annular portion comprises fibres having a dpf of less than or equal to 10.0. Even more preferably, the annular portion comprises fibres having a dpf of less than or equal to 9.0.
  • the annular portion comprises fibres having a dpf of from 3.0 to 15.0, preferably from 3.0 to 10.0, more preferably from 3.0 to 9.0. In other embodiments, the annular portion comprises fibres having a dpf of from 5.0 to 15.0, preferably from 5.0 to 10.0, more preferably from 5.0 to 9.0. In further embodiments, the annular portion comprises fibres having a dpf of from 6.0 to 15.0, preferably from 6.0 to 10.0, more preferably from 6.0 to 9.0.
  • the fibres may have a Y-shaped cross-section.
  • An outer diameter of the annular portion may be up to 10 millimetres. Preferably, an outer diameter of the annular portion is less than 9 millimetres. More preferably, an outer diameter of the annular portion is less than 7.7 millimetres.
  • a thickness of the annular portion is at least 0.5 millimetres.
  • a thickness of the annular portion is at least 1.0 millimetres. More preferably, a thickness of the annular portion is at least 1.5 millimetres.
  • a thickness of the annular portion may be less than 5.0 millimetres.
  • a thickness of the annular portion is less than 4.0 millimetres. More preferably, a thickness of the annular portion is less than 3.5 millimetres. Even more preferably, a thickness of the annular portion is less than 3.0 millimetres.
  • a thickness of the annular portion is from 0.5 millimetres to 4 millimetres, preferably from 0.5 millimetres to 3.5 millimetres, more preferably from 0.5 millimetres to 3 millimetres. In other embodiments, a thickness of the annular portion is from 1.0 millimetres to 4 millimetres, preferably from 1.0 millimetres to 3.5 millimetres, more preferably from 1.0 millimetres to 3 millimetres. In further embodiments, a thickness of the annular portion is from 1.5 millimetres to 4 millimetres, preferably from 1.5 millimetres to 3.5 millimetres, more preferably from 1.5 millimetres to 3 millimetres.
  • the annular portion radially abuts the core portion.
  • the annular portion immediately circumscribes the core portion.
  • an inner periphery of the annular portion is immediately adjacent an outer periphery of the cylindrical core portion, for example as defined by an outer surface of the core wrapper, and the annular portion thus extends radially from the outer periphery of the cylindrical core portion to the outer periphery of the annular portion.
  • an internal diameter of the annular portion substantially matches the outer diameter of the core portion.
  • an aerosol-generating article in accordance with the present invention comprises a downstream section provided downstream of the aerosol-generating rod and abutting the downstream end of the aerosol-generating rod.
  • the downstream section may have any length.
  • the downstream section may have a length of at least 10 millimetres.
  • the downstream section may have a length of at least 15 millimetres, at least 20 millimetres, at least 25 millimetres, or at least 30 millimetres.
  • a downstream section having a length greater than the values set out above may advantageously provide space for the aerosol to cool and condense before reaching the consumer. This may also ensure a user is spaced apart from the heating element when the aerosol-generating article is used in conjunction with an aerosol generating device.
  • the downstream section may have a length of no more than 80 millimetres.
  • the downstream section may have a length of no more than 70 millimetres, no more than 60 millimetres, no more than 50 millimetres, or no more than 40 millimetres.
  • a ratio between the length of the downstream section and the length of the aerosol-generating rod may be from 1.0 to 4.5.
  • a ratio between the length of the downstream section and the length of the aerosol-generating rod is at least 1.25, more preferably at least 1.5, even more preferably at least 2.0.
  • a ratio between the length of the downstream section and the length of the aerosol-generating rod is less than or equal to 4.0, preferably less than 3.5, even more preferably less than 3.0.
  • a length of the downstream section substantially corresponds to the sum of the lengths of the individual components forming the downstream section.
  • the downstream section comprises a hollow tubular element.
  • the hollow tubular element defines an internal cavity, and an upstream end of the hollow tubular element abuts the downstream end of the aerosol-generating rod.
  • an internal diameter of the annular portion is preferably smaller than an internal diameter of the hollow tubular element, such that the annular portion is in direct fluid communication with the internal cavity of the hollow tubular element.
  • a length of the hollow tubular element may be at least 5 millimetres.
  • a length of the hollow tubular element is at least 10 millimetres. More preferably, a length of the hollow tubular element is at least 12 millimetres. Even more preferably, a length of the hollow tubular element is at least 15 millimetres.
  • a length of the hollow tubular element is less than or equal to 45 millimetres. More preferably, a length of the hollow tubular element is less than or equal to 40 millimetres. Even more preferably, a length of the hollow tubular element is less than or equal to 40 millimetres.
  • a length of the hollow tubular element is less than or equal to 35 millimetres. More preferably, a length of the hollow tubular element is less than or equal to 30 millimetres. Even more preferably, a length of the hollow tubular element is less than or equal to 25 millimetres. In particularly preferred embodiments, a length of the hollow tubular element is less than or equal to 22 millimetres.
  • a length of the hollow tubular element is from 10 millimetres to 45 millimetres, preferably from 10 millimetres to 40 millimetres, more preferably from 10 millimetres to 35 millimetres, even more preferably from 10 millimetres to 30 millimetres. In particularly preferred embodiments, a length of the hollow tubular element is from 10 millimetres to 25 millimetres, preferably from 10 millimetres to 22 millimetres.
  • a length of the hollow tubular element is from 12 millimetres to 45 millimetres, preferably from 12 millimetres to 40 millimetres, more preferably from 12 millimetres to 35 millimetres, even more preferably from 12 millimetres to 30 millimetres. In particularly preferred embodiments, a length of the hollow tubular element is from 12 millimetres to 25 millimetres, preferably from 12 millimetres to 22 millimetres.
  • a length of the hollow tubular element is from 15 millimetres to 45 millimetres, preferably from 15 millimetres to 40 millimetres, more preferably from 15 millimetres to 35 millimetres, even more preferably from 15 millimetres to 30 millimetres. In particularly preferred embodiments, a length of the hollow tubular element is from 15 millimetres to 25 millimetres, preferably from 15 millimetres to 22 millimetres.
  • the hollow tubular element may have an internal diameter of at least 3.5 millimetres.
  • the hollow tubular element may have an internal diameter of at least 4 millimetres, at least 5 millimetres, or at least 6 millimetres.
  • a hollow tubular element having an internal diameter as set out above may advantageously provide sufficient rigidity and strength to the hollow tubular element.
  • the hollow tubular element may have an internal diameter of no more than 7 millimetres.
  • the hollow tubular element may have an internal diameter of no more than about 6.5 millimetres.
  • a hollow tubular element having an internal diameter as set out above may advantageously reduce the resistance to draw of the hollow tubular element.
  • the hollow tubular element may have an internal diameter of between 3.5 millimetres and 7 millimetres, between 4 millimetres and 7 millimetres, between about 5 millimetres and 7 millimetres, or between 6 millimetres and 7 millimetres.
  • the hollow tubular element may have an internal diameter of between 3.5 millimetres and 6.5 millimetres, between 4 millimetres and 6.5 millimetres, between about 5 millimetres and 6.5 millimetres, or between 6 millimetres and 6.5 millimetres.
  • An outer diameter of the hollow tubular element preferably substantially matches the outer diameter of the annular portion. This may also be approximately equal to the outer diameter of the aerosol-generating article.
  • a ratio between an internal diameter of the hollow tubular element and an external diameter of the hollow tubular element may be at least about 0.8.
  • the ratio between an internal diameter of the hollow tubular element and the external diameter of the hollow tubular element may be at least about 0.85, at least about 0.9, or at least about 0.95.
  • the ratio between an internal diameter of the hollow tubular element and the external diameter of the hollow tubular element may be no more than about 0.99.
  • the ratio between an internal diameter of the hollow tubular element and the external diameter of the hollow tubular element may be no more than about 0.98.
  • the ratio between an internal diameter of the hollow tubular element and the external diameter of the hollow tubular element may be about 0.97.
  • the provision of relatively large internal diameter may advantageously reduce the resistance to draw of the hollow tubular element.
  • the lumen of the hollow tubular element may have any cross sectional shape.
  • the lumen of the hollow tubular element may have a circular cross sectional shape.
  • the hollow tubular element may be formed from any material.
  • the hollow tubular element may comprise cellulose acetate tow.
  • the hollow tubular element may have a thickness of between about 0.1 millimetre and about 1 millimetre.
  • the hollow tubular element may have a thickness of about 0.5 millimetres.
  • the hollow tubular element comprises cellulose acetate tow
  • the cellulose acetate tow may have a dpf of between about 2 and about 4 and a total denier of between about 25 and about 40.
  • the hollow tubular element may comprise paper.
  • the hollow tubular element may comprise at least one layer of paper.
  • the paper may be very rigid paper.
  • the paper may be crimped paper, such as crimped heat resistant paper or crimped parchment paper.
  • the paper may be cardboard.
  • the hollow tabular element may be a paper tube.
  • the hollow tubular element may be a tube formed from spirally wound paper.
  • the hollow tabular element may be formed from a plurality of layers of the paper.
  • the paper may have a basis weight of at least about 50 grams per square meter, at least about 60 grams per square meter, at least about 70 grams per square meter, or at least about 90 grams per square meter.
  • the paper may have a thickness of at least about 50 micrometres.
  • the paper may have a thickness of at least about 70 micrometres, at least about 90 micrometres, or at least about 100 micrometres.
  • the hollow tubular element may comprise a polymer.
  • the hollow tubular element may comprise a polymeric film.
  • the polymeric film may comprise a cellulosic film.
  • the hollow tubular element may comprise low density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibres.
  • LDPE low density polyethylene
  • PHA polyhydroxyalkanoate
  • an internal diameter of the annular portion is smaller than an internal diameter of the hollow tubular element.
  • direct fluid communication is established between the annular portion and the internal cavity defined by the hollow tubular element.
  • the aerosol-generating article when the aerosol-generating article is not received within an aerosol-generating device or is received within an aerosol-generating device not devised for use with the aerosol-generating article, air drawn into the aerosol-generating rod from the upstream end will flow primarily through the annular portion and directly into the cavity of the hollow tubular element.
  • the RTD encountered by such flow of air along the aerosol-generating article will depend solely on any component of the downstream section other than the hollow tubular element, if one such component is present at all.
  • the overall RTD encountered by such flow of air along the aerosol-generating article may depend solely on an RTD of the mouthpiece, which will be described in more detail below.
  • an aerosol-generating article in accordance with the present invention comprises a ventilation zone at a location along the hollow tubular element.
  • the ventilation zone may allow cooler air from outside the aerosol-generating article to enter the internal cavity of the hollow tubular element.
  • the aerosol-generating article may typically have a ventilation level of at least about 10 percent, preferably at least about 20 percent.
  • the aerosol-generating article has a ventilation level of at least about 20 percent or 25 percent or 30 percent. More preferably, the aerosol-generating article has a ventilation level of at least about 35 percent.
  • the aerosol-generating article preferably has a ventilation level of less than about 80 percent. More preferably, the aerosol-generating article has a ventilation level of less than about 60 percent or less than about 50 percent.
  • the aerosol-generating article may typically have a ventilation level of between about 10 percent and about 80 percent.
  • the aerosol-generating article has a ventilation level from about 20 percent to about 80 percent, preferably from about 20 percent to about 60 percent, more preferably from about 20 percent to about 50 percent. In other embodiments, the aerosol-generating article has a ventilation level from about 25 percent to about 80 percent, preferably from about 25 percent to about 60 percent, more preferably from about 25 percent to about 50 percent. In further embodiments, the aerosol-generating article has a ventilation level from about 30 percent to about 80 percent, preferably from about 30 percent to about 60 percent, more preferably from about 30 percent to about 50 percent.
  • the aerosol-generating article has a ventilation level from about 40 percent to about 50 percent. In some particularly preferred embodiments, the aerosol-generating article has a ventilation level of about 45 percent.
  • the inventors have found that the temperature drop caused by the admission of cooler, external air into the hollow tubular segment may have an advantageous effect on the nucleation and growth of aerosol particles.
  • Formation of an aerosol from a gaseous mixture containing various chemical species depends on a delicate interplay between nucleation, evaporation, and condensation, as well as coalescence, all the while accounting for variations in vapour concentration, temperature, and velocity fields.
  • the so-called classical nucleation theory is based on the assumption that a fraction of the molecules in the gas phase are large enough to stay coherent for long times with sufficient probability (for example, a probability of one half).
  • These molecules represent some kind of a critical, threshold molecule clusters among transient molecular aggregates, meaning that, on average, smaller molecule clusters are likely to disintegrate rather quickly into the gas phase, while larger clusters are, on average, likely to grow.
  • Such critical cluster is identified as the key nucleation core from which droplets are expected to grow due to condensation of molecules from the vapour. It is assumed that virgin droplets that just nucleated emerge with a certain original diameter, and then may grow by several orders of magnitude. This is facilitated and may be enhanced by rapid cooling of the surrounding vapour, which induces condensation. In this connection, it helps to bear in mind that evaporation and condensation are two sides of one same mechanism, namely gas-liquid mass transfer. While evaporation relates to net mass transfer from the liquid droplets to the gas phase, condensation is net mass transfer from the gas phase to the droplet phase. Evaporation (or condensation) will make the droplets shrink (or grow), but it will not change the number of droplets.
  • the temperature and rate of cooling can play a critical role in determining how the system responds.
  • different cooling rates may lead to significantly different temporal behaviours as concerns the formation of the liquid phase (droplets), because the nucleation process is typically nonlinear.
  • nucleation burst a strong, short-lived increase in this growth.
  • This nucleation burst would appear to be more significant at lower temperatures.
  • higher cooling rates may favour an earlier onset of nucleation.
  • a reduction of the cooling rate would appear to have a favourable effect on the final size that the aerosol droplets ultimately reach.
  • the rapid cooling induced by the admission of external air into the hollow tubular segment can be favourably used to favour nucleation and growth of aerosol droplets.
  • the admission of external air into the hollow tubular segment has the immediate drawback of diluting the aerosol stream delivered to the consumer.
  • the inventors have surprisingly found that the diluting effect on the aerosol - which can be assessed by measuring, in particular, the effect on the delivery of aerosol former (such as glycerol) included in the aerosol-generating substrate) is advantageously minimised when the ventilation level is within the ranges described above.
  • aerosol former such as glycerol
  • ventilation levels between 25 percent and 50 percent, and even more preferably between 28 and 42 percent, have been found to lead to particularly satisfactory values of glycerin delivery.
  • the extent of nucleation and, as a consequence, the delivery of nicotine and aerosol-former (for example, glycerol) are enhanced.
  • a thickness of a peripheral wall (in other words, the wall thickness) of the hollow tubular element may be at least about 100 micrometres.
  • the wall thickness of the hollow tubular element may be at least about 150 micrometres.
  • the wall thickness of the hollow tubular element may be at least about 200 micrometres, preferably at least about 250 micrometres and even more preferably at least about 500 micrometres (or 0.5 mm).
  • the wall thickness of the hollow tubular element may be less than or equal to 2 millimetres, preferably less than or equal to 1.5 millimetres and even more preferably less than or equal to 1.25 mm.
  • the wall thickness of the hollow tubular element may be less than or equal to 1 millimetre.
  • the wall thickness of the hollow tubular element may be less than or equal to 500 micrometres.
  • the wall thickness of the hollow tubular element may between 100 micrometres and 2 millimetres, preferably between 150 micrometres and 1.5 millimetres, even more preferably between 200 micrometres and 1.25 millimetres.
  • the wall thickness of the hollow tubular element may preferably be about 250 micrometres (0.25 mm).
  • the thickness of the peripheral wall of the hollow tubular element relatively low ensures that the overall internal volume of the hollow tubular element - which is made available for the aerosol to begin the nucleation process as soon as the aerosol components leave the rod of aerosol-generating substrate - and the cross-sectional surface area of the hollow tubular element are effectively maximised, whilst at the same time ensuring that the hollow tubular element has the necessary structural strength to prevent a collapse of the aerosol-generating article as well as to provide some support to the aerosol-generating rod, and that the RTD of the hollow tubular element is minimised.
  • the ventilation zone may comprise a first line of perforation holes circumscribing the hollow tubular element.
  • the ventilation zone may comprise two circumferential rows of perforation holes.
  • the perforation holes may be formed online during manufacturing of the aerosol-generating article.
  • Each circumferential row of perforation holes may comprise between about 5 and about 40 perforations, for example each circumferential row of perforation holes may comprise between about 8 and about 30 perforations.
  • the ventilation zone preferably comprises at least one corresponding circumferential row of perforation holes provided through a portion of the combining plug wrap. These may also be formed online during manufacture of the smoking article. Preferably, the circumferential row or rows of perforation holes provided through a portion of the combining plug wrap are in substantial alignment with the row or rows of perforations through the downstream section.
  • the ventilation zone preferably comprises at least one corresponding circumferential row of perforation holes provided through the band of tipping paper. These may also be formed online during manufacture of the smoking article.
  • the circumferential row or rows of perforation holes provided through the band of tipping paper are in substantial alignment with the row or rows of perforations through the downstream section.
  • the ventilation zone may be located anywhere along the length of the hollow tubular element.
  • the ventilation zone may be located at least 8 millimetres from a downstream end of the aerosol-generating article.
  • the ventilation zone may be located at least 10 millimetres, at least 12 millimetres, or at least 15 millimetres from the downstream end of the aerosol-generating article. Locating the first ventilation zone as outlined above may advantageously prevent the first ventilation zone being occluded by a consumer's mouth or lips when the aerosol-generating article is in use.
  • the ventilation zone may be located no more than 25 millimetres from the downstream end of the aerosol-generating article.
  • the ventilation zone may be located 20 millimetres from the downstream end of the aerosol generating article. Locating the ventilation zone as outlined above may advantageously prevent the ventilation zone being occluded when the aerosol-generating article is inserted into an aerosol generating device.
  • the ventilation zone may be located at least 2 millimetres from an upstream end of the hollow tubular element.
  • the ventilation zone may be located at least 3 millimetres from an upstream end of the hollow tubular element or at least 4 millimetres from an upstream end of the hollow tubular element or at least 5 millimetres from an upstream end of the hollow tubular element.
  • the ventilation zone may be located less than 20 millimetres from a downstream end of the hollow tubular element, preferably less than 18 millimetres from a downstream end of the hollow tubular element, more preferably less than 16 millimetres from a downstream end of the hollow tubular element, even more preferably less than 14 millimetres from a downstream end of the hollow tubular element.
  • a hollow tubular element provides an unrestricted flow channel. This means that the hollow tubular element provides a negligible level of resistance to draw (RTD).
  • RTD resistance to draw
  • the term "negligible level of RTD” is used to describe an RTD of less than 1 mm H 2 O per 10 millimetres of length of the hollow tubular element or hollow tubular element, preferably less than 0.4 mm H 2 O per 10 millimetres of length of the hollow tubular element or hollow tubular element, more preferably less than 0.1 mm H 2 O per 10 millimetres of length of the hollow tubular element or hollow tubular element.
  • the resistance to draw (RTD) of a component or the aerosol-generating article is measured in accordance with ISO 6565-2015.
  • the RTD refers the pressure required to force air through the full length of a component.
  • the terms "pressure drop” or “draw resistance” of a component or article may also refer to the "resistance to draw”.
  • Such terms generally refer to the measurements in accordance with ISO 6565-2015 are normally carried out at under test at a volumetric flow rate of about 17.5 millilitres per second at the output or downstream end of the measured component at a temperature of about 22 degrees Celsius, a pressure of about 101 kPa (about 760 Torr) and a relative humidity of about 60 percent.
  • the RTD of a hollow tubular element is preferably less than or equal to about 10 millimetres H 2 O. More preferably, the RTD of a hollow tubular element is less than or equal to about 5 millimetres H 2 O. Even more preferably, the RTD of a hollow tubular element is less than or equal to about 2.5 millimetres H 2 O. Even more preferably, the RTD of the hollow tubular element is less than or equal to about 2 millimetres H 2 O. Even more preferably, the RTD of the hollow tubular element is less than or equal to about 1 millimetre H 2 O.
  • the RTD of a hollow tubular element may be at least 0 millimetres H 2 O, or at least about 0.25 millimetres H 2 O or at least about 0.5 millimetres H 2 O or at least about 1 millimetre H 2 O.
  • the RTD of a hollow tubular element is from about 0 millimetre H 2 O to about 10 millimetres H 2 O, preferably from about 0.25 millimetres H 2 O to about 10 millimetres H 2 O, preferably from about 0.5 millimetres H 2 O to about 10 millimetres H 2 O. In other embodiments, the RTD of a hollow tubular element is from about 0 millimetres H 2 O to about 5 millimetres H 2 O, preferably from about 0.25 millimetres H 2 O to about 5 millimetres H 2 O preferably from about 0.5 millimetres H 2 O to about 5 millimetres H 2 O.
  • the RTD of a hollow tubular element is from about 1 millimetre H 2 O to about 5 millimetres H 2 O. In further embodiments, the RTD of a hollow tubular element is from about 0 millimetres H 2 O to about 2.5 millimetres H 2 O, preferably from about 0.25 millimetres H 2 O to about 2.5 millimetres H 2 O, more preferably from about 0.5 millimetres H 2 O to about 2.5 millimetres H 2 O.
  • the RTD of a hollow tubular element is from about 0 millimetres H 2 O to about 2 millimetres H 2 O, preferably from about 0.25 millimetres H 2 O to about 2 millimetres H 2 O, more preferably from about 0.5 millimetres H 2 O to about 2 millimetres H 2 O. In a particularly preferred embodiment, the RTD of a hollow tubular element is about 0 millimetre H 2 O.
  • the overall RTD of the article depends essentially on the RTD of the aerosol-generating rod and may optionally also depend on the RTD of other components of the downstream section, such as for example a mouthpiece, as will be described below.
  • the hollow tubular segment is substantially empty and, as such, substantially only marginally contribute to the overall RTD of the aerosol-generating article.
  • the internal cavity of the hollow tubular element should therefore be free from any components that would obstruct the flow of air in a longitudinal direction.
  • the internal cavity is substantially empty.
  • the overall RTD of the article is primarily dependent on the core portion and optionally on components of the downstream section other than the hollow tubular element.
  • the downstream section may comprise a mouthpiece element.
  • the downstream section comprises a mouthpiece element downstream of the hollow tubular element, and the article further comprises a wrapper circumscribing the aerosol-generating rod, the hollow tubular element and the mouthpiece.
  • the mouthpiece element may be located immediately downstream of the hollow tubular element.
  • the mouthpiece element may extend from a downstream end of the hollow tubular element to a mouth end of the aerosol-generating article or to the downstream end of the downstream section.
  • the internal cavity of the hollow tubular element is in direct fluid communication with the mouthpiece element.
  • a length of the mouthpiece element may be at least 5 millimetres.
  • a length of the mouthpiece element is at least 10 millimetres. More preferably, a length of the mouthpiece element is at least 12 millimetres. Even more preferably, a length of the mouthpiece element is at least 15 millimetres.
  • a length of the mouthpiece element is less than or equal to 45 millimetres. More preferably, a length of the mouthpiece element is less than or equal to 40 millimetres. Even more preferably, a length of the mouthpiece element is less than or equal to 40 millimetres.
  • a length of the mouthpiece element is less than or equal to 35 millimetres. More preferably, a length of the mouthpiece element is less than or equal to 30 millimetres. Even more preferably, a length of the mouthpiece element is less than or equal to 25 millimetres. In particularly preferred embodiments, a length of the mouthpiece element is less than or equal to 22 millimetres.
  • a length of the mouthpiece element is from 10 millimetres to 45 millimetres, preferably from 10 millimetres to 40 millimetres, more preferably from 10 millimetres to 35 millimetres, even more preferably from 10 millimetres to 30 millimetres. In particularly preferred embodiments, a length of the mouthpiece element is from 10 millimetres to 25 millimetres, preferably from 10 millimetres to 22 millimetres.
  • a length of the mouthpiece element is from 12 millimetres to 45 millimetres, preferably from 12 millimetres to 40 millimetres, more preferably from 12 millimetres to 35 millimetres, even more preferably from 12 millimetres to 30 millimetres. In particularly preferred embodiments, a length of the mouthpiece element is from 12 millimetres to 25 millimetres, preferably from 12 millimetres to 22 millimetres.
  • a length of the mouthpiece element is from 15 millimetres to 45 millimetres, preferably from 15 millimetres to 40 millimetres, more preferably from 15 millimetres to 35 millimetres, even more preferably from 15 millimetres to 30 millimetres. In particularly preferred embodiments, a length of the mouthpiece element is from 15 millimetres to 25 millimetres, preferably from 15 millimetres to 22 millimetres.
  • An outer diameter of the mouthpiece element preferably substantially matches an outer diameter of the annular portion or an outer diameter of the hollow tubular element or both.
  • the mouthpiece element may be formed of a fibrous material.
  • the mouthpiece element may be formed of a porous material.
  • the mouthpiece element may be formed of a biodegradable material.
  • the mouthpiece element may be formed of a cellulose material, such as cellulose acetate.
  • the mouthpiece element may be formed of a polylactic acid based material.
  • the mouthpiece element may be formed of a bioplastic material, preferably a starch-based bioplastic material.
  • the mouthpiece element may be made by injection moulding or by extrusion.
  • Bioplastic-based materials are advantageous because they are able to provide mouthpiece element structures that are simple and cheap to manufacture with a particular and complex cross-sectional profile, which may comprise a plurality of relatively large air flow channels extending through the mouthpiece element material, that provides suitable RTD characteristics.
  • the mouthpiece element may be formed from a sheet of suitable material that has been crimped, pleated, gathered, woven or folded into an element that defines a plurality of longitudinally extending channels.
  • Such sheet of suitable material may be formed of paper, cardboard, a polymer, such as polylactic acid, or any other cellulose-based, paper-based material or bioplastic-based material.
  • a cross-sectional profile of such a mouthpiece element may show the channels as being randomly oriented.
  • the mouthpiece element may be formed in any other suitable manner.
  • the mouthpiece element may be formed from a bundle of longitudinally extending tubes.
  • the longitudinally extending tubes may be formed from polylactic acid.
  • the mouthpiece element may be formed by extrusion, moulding, lamination, injection, or shredding of a suitable material.
  • the mouthpiece element may comprise at least one filter (air flow) channel extending along the mouthpiece element.
  • the at least one filter air flow channel extend along the whole length of the mouthpiece element.
  • the at least one filter channel may have a substantially circular cross-section.
  • the at least one filter channel may have a substantially Y-shaped or T-shaped cross-section.
  • the mouthpiece element may comprises a plurality of such filter air flow channels extending along the mouthpiece element.
  • the mouthpiece element may comprise at least three filter air flow channels. The provision of at least one filter air flow channel in the mouthpiece element allows the mouthpiece element to meet particular RTD values.
  • the resistance to draw (RTD) of the mouthpiece element may be at least about 0 mm H 2 O.
  • the RTD of the mouthpiece element may be at least about 3 mm H 2 O.
  • the RTD of the mouthpiece element may be at least about 6 mm H 2 O.
  • the RTD of the mouthpiece element may be no greater than about 12 mm H 2 O.
  • the RTD of the mouthpiece element may be no greater than about 11 mm H 2 O.
  • the RTD of the mouthpiece element may be no greater than about 10 mm H 2 O.
  • the resistance to draw of the mouthpiece element may be greater than or equal to about 0 mm H 2 O and less than about 12 mm H 2 O.
  • the resistance to draw of the mouthpiece element may be greater than or equal to about 3 mm H 2 O and less than about 12 mm H 2 O.
  • the resistance to draw of the mouthpiece element may be greater than or equal to about 0 mm H 2 O and less than about 11 mm H 2 O.
  • the resistance to draw of the mouthpiece element may be greater than or equal to about 3 mm H 2 O and less than about 11 mm H 2 O.
  • the resistance to draw of the mouthpiece element may be greater than or equal to about 6 mm H 2 O and less than about 10 mm H 2 O.
  • the resistance to draw of the mouthpiece element may be about 8 mm H 2 O.
  • the aerosol-generating article may have an overall length from about 30 millimetres to about 110 millimetres.
  • an overall length of an aerosol-generating article in accordance with the invention is at least about 30 millimetres. More preferably, an overall length of an aerosol-generating article in accordance with the invention is at least about 40 millimetres. Even more preferably, an overall length of an aerosol-generating article in accordance with the invention is at least about 42 millimetres.
  • An overall length of an aerosol-generating article in accordance with the invention is preferably less than or equal to 90 millimetres. More preferably, an overall length of an aerosol-generating article in accordance with the invention is preferably less than or equal to 80 millimetres. Even more preferably, an overall length of an aerosol-generating article in accordance with the invention is preferably less than or equal to 70 millimetres.
  • an overall length of the aerosol-generating article is preferably from 30 millimetres to 90 millimetres, more preferably from 40 millimetres to 90 millimetres, even more preferably from 42 millimetres to 90 millimetres. In other embodiments, an overall length of the aerosol-generating article is preferably from 30 millimetres to 80 millimetres, more preferably from 40 millimetres to 80 millimetres, even more preferably from 42 millimetres to 80 millimetres. In further embodiments, an overall length of the aerosol-generating article is preferably from 30 millimetres to 70 millimetres, more preferably from 40 millimetres to 70 millimetres, even more preferably from 42 millimetres to 70 millimetres.
  • An outer diameter of the aerosol-generating article may be at least 4 millimetres. Preferably, an outer diameter of the aerosol-generating article is at least 5 millimetres. More preferably, outer diameter of the aerosol-generating article is at least 6 millimetres. An outer diameter of the aerosol-generating article is preferably less than or equal to 12 millimetres, more preferably less than or equal to 10 millimetres, even more preferably less than or equal to 8 millimetres.
  • an outer diameter of the aerosol-generating article is from 4 millimetres to 12 millimetres, preferably from 4 millimetres to 10 millimetres, more preferably from 4 millimetres to 8 millimetres. In other embodiments, an outer diameter of the aerosol-generating article is from 5 millimetres to 12 millimetres, preferably from 5 millimetres to 10 millimetres, more preferably from 5 millimetres to 8 millimetres. In further embodiments, an outer diameter of the aerosol-generating article is from 6 millimetres to 12 millimetres, preferably from 6 millimetres to 10 millimetres, more preferably from 6 millimetres to 8 millimetres.
  • the outer diameter of the aerosol-generating article may be substantially constant over the whole length of the aerosol-generating article. As an alternative, different portions of the aerosol-generating article may have different outer diameters.
  • one or more of the components of the aerosol-generating article are individually circumscribed by their own wrapper.
  • the aerosol-generating rod and the mouthpiece element are individually wrapped.
  • the aerosol-generating rod and the hollow tubular element are then combined together with an outer wrapper.
  • the combined aerosol-generating rod and hollow tubular element are further combined with the mouthpiece element - which has its own wrapper - by means of tipping paper.
  • At least one of the components of the aerosol-generating article is wrapped in a hydrophobic wrapper.
  • hydrophobic refers to a surface exhibiting water repelling properties.
  • the “water contact angle” is the angle, conventionally measured through the liquid, where a liquid/vapour interface meets a solid surface. It quantifies the wettability of a solid surface by a liquid via the Young equation. Hydrophobicity or water contact angle may be determined by utilizing TAPPI T558 test method and the result is presented as an interfacial contact angle and reported in "degrees" and can range from near zero to near 180 degrees.
  • the hydrophobic wrapper is one including a paper layer having a water contact angle of about 30 degrees or greater, and preferably about 35 degrees or greater, or about 40 degrees or greater, or about 45 degrees or greater.
  • the paper layer may comprise PVOH (polyvinyl alcohol) or silicon.
  • PVOH polyvinyl alcohol
  • the PVOH may be applied to the paper layer as a surface coating, or the paper layer may comprise a surface treatment comprising PVOH or silicon.
  • an aerosol-generating article in accordance with the present invention comprises, in linear sequential arrangement, an aerosol-generating rod, a hollow tubular element located immediately downstream of the aerosol-generating rod, a mouthpiece element located immediately downstream of the hollow tubular element, and one or more outer wrappers combining the aerosol-generating rod, the hollow tubular element and the mouthpiece element.
  • the hollow tubular element and the mouthpiece element form the downstream section of the aerosol-generating article.
  • the hollow tubular element may abut the aerosol-generating rod.
  • the mouthpiece element may abut the hollow tubular element.
  • the hollow tubular element abuts the aerosol-generating rod and the mouthpiece element abuts the hollow tubular element.
  • the aerosol-generating article has a substantially cylindrical shape and an outer diameter of from 4.9 millimetres to 9 millimetres. In an especially preferred embodiment, the aerosol-generating article has a substantially cylindrical shape and an outer diameter of 7.7 millimetres.
  • An overall length of the aerosol-generating article is from 30 millimetres to 75 millimetres, in an especially preferred embodiment 45 millimetres.
  • the aerosol-generating rod has a length of from 5 millimetres to 25 millimetres. In an especially preferred embodiment, the aerosol-generating rod has a length of about 11 millimetres.
  • the hollow tubular element has a length of from 5 millimetres to 35 millimetres. In an especially preferred embodiment, the hollow tubular element has a length of about 11 millimetres.
  • the mouthpiece element has a length of from 5 millimetres to 15 millimetres. In an especially preferred embodiment, the mouthpiece has a length of about 22 millimetres.
  • An overall length of the article is from 15 millimetres to 75 millimetres.
  • the aerosol-generating article has a length of about 45 millimetres.
  • the aerosol-generating rod comprises a core portion that contains at least one of the types of aerosol-generating substrate described above, and preferably a shredded tobacco material or a gathered homogenised tobacco material.
  • the core portion comprises a shredded tobacco material comprising from 13 percent by weight to 18 percent by weight of glycerol.
  • the aerosol-generating rod comprises an annular portion that radially abuts the core portion and has an outer diameter substantially matching an outer diameter of the aerosol-generating article and .
  • a thickness of the annular portion is 1.8 millimetres.
  • An internal diameter of the annular portion substantially matches an outer diameter of the core portion.
  • the annular portion is formed of a plurality of linear, axially extending fibres of at least one of the types described above.
  • the hollow tubular element is in the form of a cardboard tube or a cellulose acetate tube and has an internal diameter of from 3.4 millimetres to 9.5 millimetres.
  • a thickness of a peripheral wall of the hollow tube segment is about 0.5 millimetres to 1.8 millimetres.
  • a ventilation zone comprising a circumferential row of openings is provided along the hollow tubular element at 5 to 30 millimetres from an upstream end of the hollow tubular element.
  • the mouthpiece element is in the form of a low-density cellulose acetate filter segment.
  • an aerosol-generating system comprising an aerosol-generating device having a distal end and a mouth end.
  • the aerosol-generating device may comprise a body.
  • the body or housing of the aerosol-generating device may define a device cavity for removably receiving the aerosol-generating article at the mouth end of the device.
  • the aerosol-generating device may comprise a heating element or heater for heating the aerosol-generating substrate when the aerosol-generating article is received within the device cavity.
  • the device cavity may be referred to as the heating chamber of the aerosol-generating device.
  • the device cavity may extend between a distal end and a mouth, or proximal, end.
  • the distal end of the device cavity may be a closed end and the mouth, or proximal, end of the device cavity may be an open end.
  • An aerosol-generating article may be inserted into the device cavity, or heating chamber, via the open end of the device cavity.
  • the device cavity may be cylindrical in shape so as to conform to the same shape of an aerosol-generating article.
  • the expression “received within” may refer to the fact that a component or element is fully or partially received within another component or element.
  • the expression “aerosol-generating article is received within the device cavity” refers to the aerosol-generating article being fully or partially received within the device cavity of the aerosol-generating article.
  • the aerosol-generating article may abut the distal end of the device cavity.
  • the aerosol-generating article may be in substantial proximity to the distal end of the device cavity.
  • the distal end of the device cavity may be defined by an end-wall.
  • the length of the device cavity may be between about 10 mm and about 50 mm.
  • the length of the device cavity may be between about 20 mm and about 40 mm.
  • the length of the device cavity may be between about 25 mm and about 30 mm.
  • the length of the device cavity may be the same as or greater than the length of the aerosol-generating rod.
  • the length of the device cavity may be such that the downstream section or a portion thereof is configured to protrude from the device cavity, when the aerosol-generating article is received within the device cavity.
  • the length of the device cavity may be such that a portion of the downstream section (such as the hollow tubular element or mouthpiece element) is configured to protrude from the device cavity, when the aerosol-generating article is received within the device cavity.
  • the length of the device cavity may be such that a portion of the downstream section (such as the hollow tubular element or mouthpiece element) is configured to be received within the device cavity, when the aerosol-generating article is received within the device cavity.
  • a diameter of the device cavity may be between about 4 mm and about 10 mm.
  • a diameter of the device cavity may be between about 5 mm and about 9 mm.
  • a diameter of the device cavity may be between about 6 mm and about 8 mm.
  • a diameter of the device cavity may be between about 7 mm and about 8 mm.
  • a diameter of the device cavity may be between about 7 mm and about 7.5 mm.
  • a diameter of the device cavity may be substantially the same as or greater than a diameter of the aerosol-generating article.
  • a diameter of the device cavity may be the same as a diameter of the aerosol-generating article in order to establish a tight fit with the aerosol-generating article.
  • the device cavity may be configured to establish a tight fit with an aerosol-generating article received within the device cavity. Tight fit may refer to a snug fit.
  • the aerosol-generating device may comprise a peripheral wall. Such a peripheral wall may define the device cavity, or heating chamber. The peripheral wall defining the device cavity may be configured to engage with an aerosol-generating article received within the device cavity in a tight fit manner, so that there is substantially no gap or empty space between the peripheral wall defining the device cavity and the aerosol-generating article when received within the device.
  • Such a tight fit may establish an airtight fit or configuration between the device cavity and an aerosol-generating article received therein.
  • the tight fit with an aerosol-generating article may be established along the entire length of the device cavity or along a portion of the length of the device cavity.
  • the aerosol-generating device comprises an air-flow channel extending between a channel inlet and a channel outlet.
  • the airflow channel may be configured to establish a fluid communication between the interior of the device cavity and the exterior of the aerosol-generating device.
  • the airflow channel of the aerosol-generating device may be defined within the housing of the aerosol-generating device to enable fluid communication between the interior of the device cavity and the exterior of the aerosol-generating device.
  • the airflow channel When an aerosol-generating article is received within the device cavity, the airflow channel may be configured to provide air flow into the article in order to deliver generated aerosol to a user drawing from the mouth end of the article.
  • the aerosol-generating device comprises a heating chamber at a proximal end to at least partly receive the aerosol-generating rod to heat the aerosol-generating substrate, and the aerosol-generating device comprising an opening at a distal end to admit airflow into the heating chamber along a longitudinal axis of the heating chamber.
  • a diameter of such opening, which defines an airflow channel as described above, is smaller than the internal diameter of the annular portion.
  • an overall RTD of the aerosol-generating article will substantially correspond to a sum of the RTD of the core portion and an RTD of the downstream section.
  • an RTD of the aerosol-generating system may be at least 60 millimetres H 2 O, preferably at least 70 millimetres H 2 O, more preferably at least 80 millimetres H 2 O.
  • an RTD of the aerosol-generating system may be less than or equal to 160 millimetres H 2 O, preferably less than or equal to 150 millimetres H 2 O, more preferably less than or equal to 140 millimetres H 2 O.
  • the heater in the aerosol-generating device is an internal heater, such as a pin heater of blade heater that is configured for insertion into the core portion when the aerosol-generating article is received within the heating chamber.
  • the heater may be positioned within the device cavity, or heating chamber.
  • the heater may comprises one or more resistive heating elements.
  • Suitable materials for forming the one or more resistive heating elements include but are not limited to: semiconductors such as doped ceramics, electrically 'conductive' ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys and composite materials made of a ceramic material and a metallic material.
  • Such composite materials may comprise doped or undoped ceramics.
  • suitable doped ceramics include doped silicon carbides.
  • suitable metals include titanium, zirconium, tantalum and metals from the platinum group.
  • suitable metal alloys include stainless steel, nickel-, cobalt-, chromium-, aluminium- titanium- zirconium-, hafnium-, niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese- and iron-containing alloys, and super-alloys based on nickel, iron, cobalt, stainless steel, Timetal ® and iron-manganese-aluminium based alloys.
  • the one or more resistive heating elements comprise one or more stamped portions of electrically resistive material, such as stainless steel.
  • the at least one resistive heating element may comprise a heating wire or filament, for example a Ni-Cr (Nickel-Chromium), platinum, tungsten or alloy wire.
  • the heater comprises an electrically insulating substrate, wherein the one or more resistive heating element are provided on the electrically insulating substrate.
  • the electrically insulating substrate may comprise any suitable material.
  • the electrically insulating substrate may comprise one or more of: paper, glass, ceramic, anodized metal, coated metal, and Polyimide.
  • the ceramic may comprise mica, Alumina (Al 2 O 3 ) or Zirconia (ZrO 2 ).
  • the electrically insulating substrate has a thermal conductivity of less than or equal to about 40 Watts per metre Kelvin, preferably less than or equal to about 20 Watts per metre Kelvin and ideally less than or equal to about 2 Watts per metre Kelvin.
  • the heater may comprise a heating element comprising a rigid electrically insulating substrate with one or more electrically conductive tracks or wire disposed on its surface.
  • the size and shape of the electrically insulating substrate may allow it to be inserted directly into an aerosol-generating substrate. If the electrically insulating substrate is not sufficiently rigid, the heating element may comprise a further reinforcement means. A current may be passed through the one or more electrically conductive tracks to heat the heating element and the aerosol-generating substrate.
  • the aerosol-generating article comprises a susceptor element embedded within the core portion and adapted to heat the aerosol-generating substrate.
  • the heater in the aerosol-generating device may comprise an inductive heating arrangement.
  • the inductive heating arrangement may comprise an inductor coil and a power supply configured to provide high frequency oscillating current to the inductor coil.
  • a high frequency oscillating current means an oscillating current having a frequency of between about 500 kHz and about 30 MHz.
  • the heater may advantageously comprise a DC/AC inverter for converting a DC current supplied by a DC power supply to the alternating current.
  • the inductor coil may be arranged to generate a high frequency oscillating electromagnetic field on receiving a high frequency oscillating current from the power supply.
  • the inductor coil may be arranged to generate a high frequency oscillating electromagnetic field in the device cavity.
  • the inductor coil may substantially circumscribe the device cavity.
  • the inductor coil may extend at least partially along the length of the device cavity.
  • the heater may be controlled to operate within a defined operating temperature range, below a maximum operating temperature.
  • An operating temperature range between about 150 degrees Celsius and about 300 degrees Celsius in the heating chamber (or device cavity) is preferable.
  • the operating temperature range of the heater may be between about 150 degrees Celsius and about 250 degrees Celsius.
  • the operating temperature range of the heater may be between about 150 degrees Celsius and about 200 degrees Celsius. More preferably, the operating temperature range of the heater may be between about 180 degrees Celsius and about 200 degrees Celsius.
  • the aerosol-generating device may comprise a power supply.
  • the power supply may be a DC power supply.
  • the power supply is a battery.
  • the power supply may be a nickel-metal hydride battery, a nickel cadmium battery, or a lithium based battery, for example a lithium-cobalt, a lithium-iron-phosphate or a lithium-polymer battery.
  • the power supply may be another form of charge storage device, such as a capacitor.
  • the power supply may require recharging and may have a capacity that allows for the storage of enough energy for one or more user operations, for example one or more aerosol-generating experiences.
  • the power supply may have sufficient capacity to allow for continuous heating of an aerosol-generating substrate for a period of around six minutes, corresponding to the typical time taken to smoke a conventional cigarette, or for a period that is a multiple of six minutes.
  • the power supply may have sufficient capacity to allow for a predetermined number of puffs or discrete activations of the heater.
  • the aerosol-generating article 10 shown in Figure 1 comprises an aerosol-generating rod 12 and a downstream section 14 at a location downstream of the aerosol-generating rod 12.
  • the aerosol-generating article 10 extends from an upstream or distal end 16 - which substantially coincides with an upstream end of the aerosol-generating rod 12 - to a downstream or mouth end 18, which coincides with a downstream end of the downstream section 14.
  • the downstream section 14 comprises a hollow tubular element 30 and a mouthpiece element 50.
  • a wrapper 24 circumscribes the aerosol-generating rod 12, the hollow tubular element 30 and the mouthpiece element 50.
  • the aerosol-generating article 10 has an overall length of about 45 millimetres and an outer diameter of about 7.7 mm.
  • the aerosol-generating rod has a length of 11 millimetres.
  • the aerosol-generating rod comprises a core portion 20, which comprises a shredded tobacco material.
  • the core portion 20 comprises a homogenised tobacco material in the form of a sheet gathered into a cylindrical shape, the homogenised tobacco material comprising from 13 percent by weight to 16 percent by weight of glycerine.
  • An average porosity of the core portion is about 0.3.
  • the aerosol-generating article 10 further comprises an elongate susceptor element 22 in the form of a plate embedded in, and thermally coupled with, the aerosol-generating substrate in the core portion 20.
  • the aerosol-generating rod further comprises an annular portion 24, which surrounds and radially abuts the core portion 20.
  • annular portion 24 substantially matches and outer diameter of the core portion.
  • the annular portion is formed of a plurality of linear, axially oriented fibres of cellulose acetate.
  • the hollow tubular element 30 has a length of about 12 millimetres, an external diameter of about 7.7 millimetres, and an internal diameter of about 5.5 millimetres. Thus, a thickness of a peripheral wall of the hollow tubular element 30 is about 1.1 millimetres.
  • the hollow tubular element 30 defines an internal cavity 32 that extends all the way from an upstream end of the hollow tubular element 30 to a downstream end of the hollow tubular element 30.
  • the internal cavity 32 is substantially empty, and so substantially unrestricted airflow is enabled along the internal cavity 32.
  • the hollow tubular element 30 does not substantially contribute to the overall RTD of the aerosol-generating article 10.
  • the annular portion 24 is in direct fluid communication with the internal cavity 32.
  • the aerosol-generating article 10 comprises a ventilation zone 40 provided at a location along the hollow tubular element 30.
  • the ventilation zone 40 is provided at about 26 millimetres from a downstream end of the article 10.
  • the ventilation zone 40 is provided 4 mm upstream from an upstream end of the mouthpiece element 50.
  • the ventilation zone 40 comprises a circumferential row of openings or perforations circumscribing the hollow tubular element 30.
  • the perforations of the ventilation zone 40 extend through the wall of the hollow tubular element 30, in order to allow fluid ingress into the internal cavity 32 from the exterior of the article 10.
  • a ventilation level of the aerosol-generating article 10 is about 16 percent.
  • the mouthpiece element 50 extends from the downstream end of the hollow tubular element 30 to the downstream or mouth end of the aerosol-generating article 10.
  • the mouthpiece element 50 has a length of about 22 mm.
  • An external diameter of the mouthpiece element 50 is about 7.7 mm.
  • the mouthpiece element 50 comprises a low-density, cellulose acetate filter segment.
  • the RTD of the mouthpiece element 50 is about 8 mm H 2 O.
  • the mouthpiece element 50 may be individually wrapped by a plug wrap (not shown).
  • the aerosol-generating article further comprises an elongate susceptor 60 in the form of a rectangular strip provided within the core portion 20.
  • Figure 3 illustrates an aerosol-generating system 100 comprising an exemplary aerosol-generating device 1 and the aerosol-generating article 10, equivalent to that shown in Figures 1 and 2 .
  • Figure 3 illustrates a downstream, mouth end portion of the aerosol-generating device 1 where the device cavity is defined and the aerosol-generating article 10 can be received.
  • the aerosol-generating device 1 comprises a housing (or body) 4.
  • the housing 4 comprises a peripheral wall 6 and an end wall 8.
  • the peripheral wall 6 defines a device cavity for receiving an aerosol-generating article 10.
  • the device cavity is defined by a closed, distal end and an open, mouth end.
  • the mouth end of the device cavity is located at the mouth end of the aerosol-generating device 1.
  • the aerosol-generating article 10 is configured to be received through the mouth end of the device cavity and is configured to abut a closed end of the device cavity.
  • a device airflow inlet 5 is defined within the end wall 8. Air may enter the core portion 20 via the device airflow inlet 5, as illustrated by the dotted arrows in Figure 3 .
  • the end wall 8 effectively occludes an end surface of the annular portion. As such, a fluid communication is selectively established between an exterior of the aerosol-generating device 1 and the aerosol-generating substrate in the core portion 20, while airflow into the annular portion is disabled.
  • the aerosol-generating device 1 further comprises a heater element in the form of an inductor coil 7 adapted to induce a current in the susceptor element 24.
  • the aerosol-generating device 1 further comprises a power source (not shown) for supplying power to the heater.
  • a controller (not shown) is also provided to control such supply of power to the heater.
  • the heater is configured to controllably heat the aerosol-generating article 10 during use, when the aerosol-generating article 1 is received within the device 1.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Medicinal Preparation (AREA)
  • Catching Or Destruction (AREA)
  • Cigarettes, Filters, And Manufacturing Of Filters (AREA)
EP22818042.8A 2021-11-23 2022-11-17 Aerosol-generating article with an aerosol-generating substrate circumscribed by a high-porosity annular portion Active EP4436412B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP21210012 2021-11-23
PCT/EP2022/082231 WO2023094254A1 (en) 2021-11-23 2022-11-17 Aerosol-generating article with an aerosol-generating substrate circumscribed by a high-porosity annular portion

Publications (3)

Publication Number Publication Date
EP4436412A1 EP4436412A1 (en) 2024-10-02
EP4436412C0 EP4436412C0 (en) 2026-02-18
EP4436412B1 true EP4436412B1 (en) 2026-02-18

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US (1) US20250009012A1 (enExample)
EP (1) EP4436412B1 (enExample)
JP (1) JP2024539441A (enExample)
KR (1) KR20240101853A (enExample)
CN (1) CN118234390A (enExample)
WO (1) WO2023094254A1 (enExample)

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GB202311831D0 (en) * 2023-08-01 2023-09-13 Nicoventures Trading Ltd A component for an aerosol provision article
TW202525173A (zh) * 2023-12-18 2025-07-01 南韓商韓國煙草人參股份有限公司 含有萊賽爾過濾嘴的吸菸製品

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US5774493A (en) 1996-08-02 1998-06-30 General Electric Company Sequence constructions for delay-and-correlate transmitted reference signaling
CN115944117A (zh) 2014-05-21 2023-04-11 菲利普莫里斯生产公司 具有内部感受器的气溶胶生成制品
NO3136881T3 (enExample) 2014-08-13 2018-04-21
EP3890517A1 (en) 2018-12-06 2021-10-13 Philip Morris Products, S.A. Aerosol-generating article with high aerosol former content
CN113260262A (zh) * 2018-12-17 2021-08-13 菲利普莫里斯生产公司 用于与气溶胶生成制品一起使用的包括多孔介质和包装物的管状元件
EP4117467B1 (en) * 2020-03-12 2024-05-01 Philip Morris Products S.A. Aerosol-generating article having a plurality of air ingress zones
WO2021180967A1 (en) * 2020-03-12 2021-09-16 Philip Morris Products S.A. Aerosol-generating system having an air ingress zone

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Publication number Publication date
KR20240101853A (ko) 2024-07-02
EP4436412C0 (en) 2026-02-18
CN118234390A (zh) 2024-06-21
EP4436412A1 (en) 2024-10-02
JP2024539441A (ja) 2024-10-28
US20250009012A1 (en) 2025-01-09
WO2023094254A1 (en) 2023-06-01

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