Cigarette with carbon on tow filter

Abstract

A cigarette comprises a tobacco rod and a carbon-on-tow filter comprising a fiber tow with flavored or unflavored carbon particles distributed throughout the tow. The carbon particles have high activity in the range of 90 to 115%, preferably 95%. As mainstream smoke is drawn through the filter, gas phase smoke constituents are removed and flavor is released when the particles are flavored. Ventilation is provided to limit the amount of tobacco being combusted during each puff and such ventilation is arranged at a location near the downstream end of the carbon-on-tow filter to lower mainstream smoke velocity through the filter. The filter achieves significant reductions in gas phase constituents of mainstream smoke, including 90% reductions or greater in at least one of 1, 3 butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile, benzene, toluene, and 80% reductions or greater in acetaldehyde over extended shelf life of the cigarettes.

1 . A cigarette comprising a tobacco rod and a carbon-on-tow filter comprising a fiber tow with carbon particles distributed amongst the tow, the carbon-on-tow filter being constructed and arranged to substantially remove at least one smoke constituent from mainstream tobacco smoke as mainstream smoke is drawn through the filter, and the carbon particles having an activity in the range of 90 to 115%.  
   
   
       2 . The cigarette as in  claim 1  wherein the carbon comprises approximately 75 to 120 milligrams or greater.  
   
   
       3 . The cigarette as in  claim 2  wherein the carbon particles are flavored.  
   
   
       4 . The cigarette as in  claim 1  wherein the carbon comprises approximately 120 milligrams.  
   
   
       5 . The cigarette as in  claim 4  wherein the carbon particles are flavored.  
   
   
       6 . The cigarette as in  claim 1  wherein the activity of the carbon particles is approximately 95%.  
   
   
       7 . The cigarette as in  claim 1  wherein the filter includes ventilation and the ventilation is in the range of 45 to 55%, and wherein a mouth end filter component is downstream of the carbon-on-tow filter component.  
   
   
       8 . The cigarette as in  claim 7  wherein the ventilation comprises at least one circumferential row of perforations through a tipping paper, the tipping paper attaching the carbon-on-tow filter to the tobacco rod.  
   
   
       9 . The cigarette as in  claim 8  wherein the ventilation is located at least 12 mm from a buccal end of the cigarette.  
   
   
       10 . The cigarette as in  claim 1 , wherein the carbon-on-tow filter achieves significant reductions in gas phase constituents of the mainstream smoke, including 90% reductions or greater in at least one of 1,3 butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile, benzene and toluene over an extended shelf life of at least six months.  
   
   
       10 . The cigarette as in  claim 1  wherein the carbon-on-tow filter achieves significant reductions in gas phase constituents of the mainstream smoke, including 80% reductions or greater of acetaldehyde.  
   
   
       11 . The cigarette as in  claim 1  wherein the filter includes a flavor release element located downstream of the carbon-on-tow.