Smoking article with mouth end cavity

Abstract

A smoking article ( 10 ) comprises a tobacco rod ( 12 ) and a filter ( 14 ) connected to the tobacco rod ( 12 ). The filter ( 14 ) comprises a first filter segment ( 18, 20 ) comprising one or more breakable capsules, wherein each breakable capsule comprises an outer shell and an inner core containing an additive. The filter ( 14 ) further comprises a hollow tube segment ( 22 ) downstream of the first filter segment ( 18, 20 ) and positioned between a downstream end of the first filter segment ( 18, 20 ) and the mouth end of the filter ( 14 ). The hollow tube segment ( 22 ) defines a cavity ( 24 ) at the mouth end of the filter ( 14 ). A plug wrap ( 23 ) circumscribes the first filter segment ( 18, 20 ) and the hollow tube segment ( 22 ), wherein the plug wrap ( 23 ) has a basis weight of less than 90 grams per square metre.

1 . A smoking article comprising:
 a tobacco rod; and   a filter connected to the tobacco rod, the filter comprising:
 a first filter segment comprising one or more breakable capsules, each breakable capsule comprising an outer shell and an inner core containing an additive; 
 a hollow tube segment downstream of the first filter segment and defining a cavity at the mouth end of the filter, the hollow tube segment positioned between a downstream end of the first filter segment and the mouth end of the filter; and 
 a plug wrap circumscribing the first filter segment and the hollow tube segment, wherein the plug wrap has a basis weight of less than 90 grams per square metre. 
   
     
     
         2 . The smoking article according to  claim 1 , wherein the ovality of the hollow tube segment after a 50% deformation of the filter is less than 25%. 
     
     
         3 . The smoking article according to  claim 1  wherein the ovality of the tube segment is less than 25% after a capsule crush test in which a force corresponding to the crush strength of the one or more capsules is applied to the first filter segment. 
     
     
         4 . A smoking article comprising:
 a tobacco rod; and   a filter connected to the tobacco rod, the filter comprising:
 a first filter segment; and 
 a hollow tube segment downstream of the first filter segment and defining a cavity at the mouth end of the filter, the hollow tube segment positioned between a downstream end of the first filter segment and the mouth end of the filter; 
 wherein the ovality of the hollow tube segment after a 50% deformation of the filter is less than 25%. 
   
     
     
         5 . The smoking article according to  claim 1 , wherein the hollow tube segment is formed from a plurality of overlapping paper layers. 
     
     
         6 . The smoking article according to  claim 5 , wherein the hollow tube segment is formed from a plurality of spirally wound paper layers. 
     
     
         7 . The smoking article according to  claim 5 , wherein adjacent paper layers of the hollow tube segment are adhered together by an intermediate layer of an adhesive. 
     
     
         8 . The smoking article according to  claim 5 , wherein the hollow tube segment comprises at least two paper layers. 
     
     
         9 . The smoking article according to  claim 1 , wherein the difference between the ovality of the tube segment after 50% deformation of the filter and the ovality of the tube segment prior to deformation of the filter is less than 25%. 
     
     
         10 . The smoking article according to  claim 1 , wherein the ovality of the hollow tube segment after a 50% deformation of the filter performed after the smoking article has been subjected to a smoking test is less than 35%. 
     
     
         11 . The smoking article according to  claim 1  wherein the hollow tube segment comprises a coating layer on an inner surface thereof. 
     
     
         12 . The smoking article according to  claim 1  wherein the compressive strength of the filter is at least 20 Newtons at 50% compression. 
     
     
         13 . The smoking article according to  claim 1  wherein the wall of the hollow tube segment has a thickness of between 150 micrometres and 500 micrometres. 
     
     
         14 . The smoking article according to  claim 1  wherein the hollow tube segment extends at least 2 mm from the downstream end of the first filter segment. 
     
     
         15 . The smoking article according to  claim 1  further comprising a rod end segment between the first filter segment and the tobacco rod.