Filter for a smoking article

Abstract

A filter for a smoking article has a first filter section comprising a filter material and a smoke modifying additive disposed in an axial region thereof and a second filter section connected to the first filter section and having at least one channel located in an axial region thereof for directing smoke, in use, through the axial region of the first filter section. The smoke modifying additive can comprise a flavourant such as menthol and the second filter section can comprise a tubular section of fibrous filter material. An adsorbent filter section can also be provided.

1 . A filter for a smoking article comprising:
 a first discrete filter section comprising filter material and a smoke modifying additive disposed in an axial region thereof; and   a second discrete filter section connected to said first filter section, the second filter section comprising filter material and at least one channel located in an axial region of the filter material, for directing smoke, in use, through the axial region of the first filter section in which the smoke modifying additive is disposed, wherein the smoke modifying additive is disposed only in said axial region of the filter material of the first filter section or in a greater concentration in said axial region than in non-axial regions of the filter material of the first filter section.   
     
     
         2 . A filter according to  claim 1 , wherein the at least one channel has a lower resistance to smoke passing through it than other regions of the filter material of the first filter section. 
     
     
         3 . A filter according to  claim 1  or  2 , wherein said channel is a hollow passageway through the second filter section. 
     
     
         4 . A filter according to any preceding claim, wherein the second filter section is connected to said first filter section so as to make the second filter section immediately either downstream or upstream of said first filter section when incorporated into a smoking article. 
     
     
         5 . A filter according to any preceding claim, wherein said axial region of said filter material of said first and/or second filter sections has a radius of from 1 mm to 4 mm and is centred on the axis of the smoking article. 
     
     
         6 . A filter according to any preceding claim, wherein the first filter section comprises continuous filter material having the smoke modifying additive disposed in the axial region thereof. 
     
     
         7 . A filter according to any preceding claim, wherein the second filter section comprises a tubular filter section. 
     
     
         8 . A filter according to  claim 7 , wherein the tubular filter section is formed from a fibrous filter material. 
     
     
         9 . A filter according to any one of the preceding claims, wherein the second filter section is configured, in use, to direct a greater portion of smoke through the axial region of the first filter section than through non-axial regions of the first filter section. 
     
     
         10 . A filter according to any one of the preceding claims, wherein the smoke modifying additive comprises an encapsulated additive. 
     
     
         11 . A filter according to  claim 10 , wherein the smoke modifying additive is contained within a capsule which is located within the first filter section at a position other than a longitudinally central position within the first filter section. 
     
     
         12 . A filter according to claim ii, wherein the capsule is located within the first filter section at a position from 1 mm to 10 mm from a longitudinally central position within the first filter section. 
     
     
         13 . A filter according to any one of  claims 1  to  9 , wherein the smoke modifying additive is disposed on a carrier material. 
     
     
         14 . A filter according to  claim 13 , wherein the carrier material comprises a thread. 
     
     
         15 . A filter according to any preceding claim, further comprising a third discrete filter section connected to said first filter section so as to make it upstream of said first filter section when incorporated into a smoking article. 
     
     
         16 . A filter according to  claim 15 , wherein the third filter section comprises fibrous filter material and a granular adsorbent material. 
     
     
         17 . A filter according to  claim 13 , wherein the granular adsorbent material is disposed in a circumferential region of the third filter section, dispersed within the filter material of the third filter section, or comprises some granular adsorbent material disposed in a circumferential region of the third filter section and some granular adsorbent material dispersed within the third filter section. 
     
     
         18 . A smoking article comprising a filter according to any one of the preceding claims. 
     
     
         19 . A smoking article according to  claim 18 , wherein the second filter section is arranged immediately downstream of said first filter section and at the mouth-end of the smoking article. 
     
     
         20 . A smoking article comprising:
 a first section comprising an aerosol generating material and an aerosol modifying additive disposed in an axial region thereof; and   a second section comprising a filter having at least one channel located in an axial region thereof for directing the aerosol generated by the aerosol generating material, in use, through the axial region of the first section.   
     
     
         21 . A smoking article according to  claim 20 , wherein the second section comprises a tubular filter section. 
     
     
         22 . A smoking article according to  claim 21 , wherein the tubular filter section is formed from a fibrous filter material. 
     
     
         23 . A smoking article according to any one of  claims 20  to  22 , wherein the aerosol modifying additive is disposed in a greater concentration in said axial region than in non-axial regions of the aerosol generating material of the first section. 
     
     
         24 . A smoking article according to any one of  claims 20  to  23 , wherein the second section, in use, directs a greater portion of smoke through the axial region of the first section than through non-axial regions of the first section.