Article with tubular aerosol-forming substrate

Abstract

An aerosol-generating article for producing an inhalable aerosol upon heating comprises a plurality of components including an aerosol-forming substrate. The aerosol-forming substrate is in the form of a hollow tubular segment defining a substrate cavity extending between an upstream end of the aerosol-forming substrate and a downstream end of the aerosol-forming substrate. The aerosol-forming substrate comprises a plurality of thermally conductive particles and an aerosol-former. The combination of tubular geometry and thermally conductive particles allows swifter time to first puff, improved efficiency of aerosol extraction and lighter weight of aerosol-generating article.

1 . An aerosol-generating article for producing an inhalable aerosol upon heating, the aerosol-generating article comprising a plurality of components including an aerosol-forming substrate, wherein the aerosol-forming substrate is in the form of a hollow tubular segment defining a substrate cavity extending between an upstream end of the aerosol-forming substrate and a downstream end of the aerosol-forming substrate, in which the aerosol-forming substrate comprises a plurality of thermally conductive particles and an aerosol-former. 
     
     
         2 . An aerosol-generating article according to  claim 1  in which the aerosol-forming substrate comprises, on a dry weight basis: between 5 and 95 wt %, for example between 10 and 90 wt %, of thermally conductive particles, each thermally conductive particle of the thermally conductive particles having a thermal conductivity of at least 1 W/(mK) in at least one direction at 25 degrees Celsius. 
     
     
         3 . An aerosol-generating article according to  claim 1 , wherein the aerosol-forming substrate has a thermal conductivity of at least 0.12 W/(mK) in at least one direction at 25 degrees Celsius. 
     
     
         4 . An aerosol-generating article according to  claim 1  in each of the thermally conductive particles consists of one or more of graphite, expanded graphite, graphene, carbon nanotubes, charcoal, and diamond. 
     
     
         5 . An aerosol-generating article according to  claim 1  in which the aerosol-forming substrate comprises, on a dry weight basis: between 10 and 90 wt % thermally conductive particles; between 7 and 60 wt % of an aerosol former; between 2 and 20 wt % of fibres; and between 2 and 10 wt % of a binder, wherein each of the thermally conductive particles consists of one or more of graphite, expanded graphite, graphene, carbon nanotubes, charcoal, and diamond. 
     
     
         6 . An aerosol-generating article according to  claim 1 , wherein the thermally conductive particles are substantially homogeneously distributed throughout the aerosol-forming substrate. 
     
     
         7 . An aerosol-generating article according to  claim 1 , wherein the aerosol-forming substrate comprises one or more organic materials such as tobacco. 
     
     
         8 . An aerosol-generating article according to  claim 1 , wherein the aerosol-forming substrate is a tobacco-free aerosol-forming substrate. 
     
     
         9 . An aerosol-generating article according to  claim 1  in which the aerosol forming substrate is in the form of a tube having an outer diameter, an inner diameter, and a length, in which the length of the tube is between 5 mm and 100 mm, the outer diameter is between 3 mm and 20 mm, and the inner diameter is between 2.5 mm and 19.5 mm. 
     
     
         10 . An aerosol-generating article according to  claim 9  in which the length of the tube is between 8 mm and 25 mm, the outer diameter of the tube is between 6 mm and 8 mm, and the inner diameter of the tube is between 5 mm and 7.9 mm. 
     
     
         11 . An aerosol-generating article according to  claim 1  in which the hollow tubular segment is a rolled sheet of aerosol-forming material, for example a rolled sheet of homogenised tobacco material or for example a rolled sheet of tobacco free aerosol-forming material. 
     
     
         12 . An aerosol-generating article according to  claim 1  any of  claims 1 to 10  in which the hollow tubular segment is an extruded tube of aerosol-forming material, for example an extruded tube of homogenised tobacco material or for example an extruded tube of tobacco-free aerosol-forming material. 
     
     
         13 . A method of forming a hollow tubular aerosol-forming substrate for an aerosol-generating article, for example an aerosol-generating article as defined by  claim 1 , the method comprising:
 forming a slurry comprising thermally conductive particles, an aerosol former, fibres, and a binder;   casting and drying the slurry to form a sheet of aerosol-forming material, and   forming the sheet into a hollow tube.   
     
     
         14 . A method according to  claim 13 , wherein forming the slurry comprises:
 forming a first mixture comprising:
 the aerosol former; 
 the fibres; 
 water; 
 optionally, a acid; and 
 optionally, nicotine, 
   forming a second mixture comprising:
 the thermally conductive particles; and 
 the binder, 
   and adding the second mixture to the first mixture to form a combined mixture.   
     
     
         15 . An aerosol-generating system comprising an aerosol-generating article according to  claim 1  and an electrical aerosol-generating device, preferably wherein the electrical aerosol-generating device is configured to resistively heat the aerosol-generating article in use, or wherein the electrical aerosol-generating device is configured to inductively heat the aerosol-generating article, for example the aerosol forming substrate of the aerosol-generating article, in use.