Filter with improved hardness and filtration efficiency

Abstract

There is provided a smoking article comprising an aerosol generating substrate and a mouthpiece attached to the aerosol generating substrate. The mouthpiece includes a segment comprising a filtration material comprising polylactic acid, and an additive for reducing phenols. The mouthpiece further comprises one or more wrappers circumscribing the segment, the one or more wrappers have a combined basis weight of at least about 50 grams per square metre (gm- 2 ).

1 . A smoking article comprising:
 an aerosol generating substrate; and   a mouthpiece attached to the aerosol generating substrate, the mouthpiece comprising a segment comprising:
 a filtration material comprising a gathered sheet of material comprising polylactic acid; 
   wherein the mouthpiece further comprises one or more wrappers circumscribing the segment, the one or more wrappers have a combined basis weight of at least about 50 grams per square metre (gm −2 ).   
     
     
         2 . A smoking article according to  claim 1  wherein the segment further comprises an additive for reducing phenols. 
     
     
         3 . (canceled) 
     
     
         4 . A smoking article according to  claim 1 , wherein the filtration material comprises a blend of polylactic acid and at least one other polymer. 
     
     
         5 . A smoking article according to  claim 4 , wherein the blend comprises a blend of polylactic acid, polyglicolic acid and poly-(L)-lactic acid. 
     
     
         6 . A smoking article according to  claim 2 , wherein the additive for reducing phenols is dispersed amongst the filtration material. 
     
     
         7 . A smoking article according to  claim 2 , wherein the additive for reducing phenols is the only additive provided in the segment. 
     
     
         8 . A smoking article according to  claim 1 , wherein the one or more wrappers comprise a first wrapper, the first wrapper being in direct abutment with the filtration material and having a basis weight of at least about 50 grams per square metre (gm −2 ). 
     
     
         9 . A smoking article according to  claim 1 , wherein the mouthpiece segment has a hardness of at least about 75%. 
     
     
         10 . A smoking article according to  claim 1 , wherein the mouthpiece segment has an ovality, after a 50% deformation of the mouthpiece segment, of less than about 25%. 
     
     
         11 . A smoking article according to  claim 1 , wherein the one or more wrappers have a combined thickness of at least about 80 μm. 
     
     
         12 . A smoking article according to  claim 1 , wherein the one or more wrappers have a combined bending stiffness of at least about 0.08 N in the machine direction of the wrapper. 
     
     
         13 . A mouthpiece for a smoking article, the mouthpiece comprising:
 a segment comprising:
 a filtration material comprising a gathered sheet of material comprising polylactic acid; 
   wherein the mouthpiece further comprises one or more wrappers circumscribing the segment, the one or more wrappers have a combined basis weight of at least about 50 grams per square metre (gm −2 ).   
     
     
         14 . A mouthpiece according to  claim 16 , wherein the blend comprises a blend of polylactic acid, polyglicolic acid and poly-(L)-lactic acid. 
     
     
         15 . A mouthpiece according to  claim 13 , wherein the one or more wrappers comprise a first wrapper, the first wrapper being in direct abutment with the filtration material and having a basis weight of at least about 50 grams per square metre (gm −2 ). 
     
     
         16 . A mouthpiece according to  claim 13 , wherein the filtration material comprises a blend of polylactic acid and at least one other polymer. 
     
     
         17 . A mouthpiece according to  claim 13 , wherein the segment further comprises an additive for reducing phenols. 
     
     
         18 . A mouthpiece according to  claim 17 , wherein the additive for reducing phenols is dispersed amongst the filtration material. 
     
     
         19 . A mouthpiece according to  claim 17 , wherein the additive for reducing phenols is the only additive provided in the segment.