Thermally-enhanced aerosol forming substrate

Abstract

An aerosol-forming substrate comprises a first material and a second material, the first material being comprised in the aerosol-forming substrate as a first plurality of discrete elements and the second material being comprised in the aerosol-forming substrate as a second plurality of discrete elements. The first material comprises an aerosol-former and has a first thermal conductivity, and the second material has a second thermal conductivity that is greater than the first thermal conductivity. The presence of the discrete elements of the second material in the aerosol-forming substrate produces a substrate with augmented thermal conductivity resulting in improvements in aerosol generation and delivery.

1 . An aerosol-forming substrate comprising a first material and a second material, the first material being comprised in the aerosol-forming substrate as a first plurality of discrete elements and the second material being comprised in the aerosol-forming substrate as a second plurality of discrete elements, in which the first material comprises an aerosol-former and has a first thermal conductivity, and in which the second material has a second thermal conductivity that is greater than the first thermal conductivity, in which the second material comprises thermally conductive particles, the thermally conductive particles being substantially homogeneously distributed throughout the second material. 
     
     
         2 . An aerosol-forming substrate according to  claim 1  in which the thermal conductivity of the second material is at least 10% greater than the thermal conductivity of the first material, for example at least 12% greater, or at least 15% greater, or at least 20% greater. 
     
     
         3 . An aerosol-forming substrate according to  claim 1  in which both the first and second plurality of discrete elements are elongated elements, each having a length dimension that is greater than a width dimension and a thickness dimension, and in which the second material comprises an aerosol former. 
     
     
         4 . An aerosol-forming substrate according to  claim 1  in which the discrete elements of the first plurality of discrete elements, or the second plurality of discrete elements, or both the first and second plurality of discrete elements have an average thickness of between 5 microns and 2000 microns, for example between 50 microns and 500 microns, for example between 150 microns and 300 microns. 
     
     
         5 . An aerosol-forming substrate according to  claim 1  in which both the first and second plurality of discrete elements are elongated elements, each having a length dimension that is greater than a width dimension and a thickness dimension. 
     
     
         6 . An aerosol-forming substrate according to  claim 1  in which the discrete elements of the first plurality of discrete elements, or the second plurality of discrete elements, or both the first and second plurality of discrete elements have an average length of between 100 microns and 60 millimetres, for example between 300 microns and 45 millimetres microns, for example between 500 microns and 30 millimetres microns, for example between 800 microns and 20 millimetres microns, for example between 1000 microns and 10 millimetres microns, for example between 1500 microns and 6000 microns. 
     
     
         7 . An aerosol-forming substrate according to  claim 1  in which the second material comprises between 1% and 95% thermally conductive particles on a dry weight basis, for example between 2% and 90% thermally conductive particles on a dry weight basis, for example between 3% and 80% thermally conductive particles on a dry weight basis, for example between 4% and 50% thermally conductive particles on a dry weight basis. 
     
     
         8 . An aerosol-forming substrate according to  claim 1  in which:
 the second material comprises thermally conductive particles formed from a thermally conductive material selected from the list consisting of carbon, graphite, expanded graphite, graphene, carbon nanoparticles, carbon nanotubes, charcoal, diamond. 
 
     
     
         9 . An aerosol-forming substrate according to  claim 1  in which the first material has a thermal conductivity of less than 0.2 W/mK, for example at 25° C., and the second material has a thermal conductivity of greater than 0.22 W/mK, for example at 25° C., for example between 0.22 W/mK and 1700 W/mK. 
     
     
         10 . An aerosol-forming substrate according to  claim 1  in which the first material comprises tobacco, for example in which the first material is formed from homogenised tobacco. 
     
     
         11 . An aerosol-forming substrate according to  claim 1  in which the second material comprises an aerosol-former and conductive particles constituting between 3 wt % and 90 wt % of the second material on a dry weight basis, the second material being configured to generate an aerosol when heated to a temperature of between 120 degrees Centigrade and 395 degrees Centigrade. 
     
     
         12 . An aerosol-forming substrate according to  claim 1  in which the second material comprises tobacco and an aerosol-former and conductive particles constituting between 3 wt % and 90 wt % of the second material on a dry weight basis, the second material being configured to generate an aerosol when heated to a temperature of between 120 degrees Centigrade and 395 degrees Centigrade. 
     
     
         13 . An aerosol-forming substrate according to  claim 11  in which the second material does not comprise tobacco, for example in which the second material is a thermally conductive tobacco-free material, and further comprises fibres and a binder. 
     
     
         14 . An aerosol-forming substrate according to  claim 1  in which the second material comprises, on a dry weight basis: between 10 and 90 wt %, for example between 20 and 85 wt % or between 40 and 80 wt %, of particulate carbon material; between 10 and 40 wt % of an aerosol former; between 4 and 20 wt % of fibres; and between 2 and 10 wt % of a binder, wherein the particulate carbon material consists of one or more of graphite, expanded graphite, graphene, carbon nanotubes, and charcoal. 
     
     
         15 . An aerosol-generating article comprising an aerosol-forming substrate according to  claim 1 , wherein the aerosol-generating article further comprises a mouth plug filter arranged at a most downstream end of the article.