Ventilated smoking article

Abstract

The invention concerns a smoking article filter plug ( 16 ) for a cigarette, the filter plug being cylindrical and having a plug wrap ( 18 ), grooves ( 20 ) being impressed into the plug wrap, and a tipping paper ( 22 ) for the attachment of the filter plug to the tobacco rod ( 12 ). Some grooves are axially extending with respect to the axis of the filter plug and are open on the side of the tobacco rod and extend continuously only over a part of the length of the filter plug. All grooves are covered by a ventilated tipping paper, which allows ventilating air into the axially extending grooves only. In addition, the invention concerns the use of such a filter for the reduction of the CO/tar ratio as a function of the filter ventilation.

1 . A smoking article incorporating a filter ( 14 ) for the reduction of the CO/tar, ratio delivered during smoking comprising a cylindrical filter plug ( 16 ) of filtration material; a plug wrap of air-impermeable material ( 18 ) around the filter plug ( 16 ); the filter comprising a first section having circumferentially spaced grooves ( 20 ) extending longitudinally along the first section of the filter plug ( 16 ) and also impressed into the plug wrap ( 18 ); and a ventilated tipping paper, connecting the filter plug ( 16 ) to a tobacco rod ( 12 ); and all of said grooves ( 20 ) being open to the tobacco rod ( 12 ) of said smoking article and extending continuously only over about 60% of the length of the filter plug ( 16 ) and separated from the mouth end of the filter ( 16 ); and wherein all grooves ( 20 ) are covered with the ventilated tipping paper ( 22 ) such that ventilating air entering said grooves ( 20 ) through said ventilated tipping paper ( 22 ) flows toward the tobacco rod and into said filter plug during smoking, wherein the grooves ( 20 ) do not connect with each other, the filter further comprising a second section aligned with the first and receiving air from the first section during smoking, wherein the second section comprises particles of activated carbon, and the first section does not contain particles of activated carbon. 
     
     
         2 . A smoking article in accordance with  claim 1 , wherein the filtration material of filter plug ( 16 ) is homogeneous over the full length of the first section of the filter plug ( 16 ). 
     
     
         3 . A smoking article in accordance with  claim 1 , wherein two to ten grooves ( 20 ) are provided. 
     
     
         4 . A smoking article in accordance with  claim 3 , wherein three to five grooves are provided. 
     
     
         5 . A smoking article in accordance with  claim 4 , wherein four grooves are provided. 
     
     
         6 . A smoking article in accordance with  claim 1 , wherein the grooves ( 20 ) are distributed symmetrically over the circumference of the filter plug ( 16 ). 
     
     
         7 . A smoking article in accordance with  claim 1  wherein the grooves ( 20 ) are V-shaped or U-shaped. 
     
     
         8 . A smoking article in accordance with  claim 1 , wherein the grooves have a depth from 0.5 to 2 mm. 
     
     
         9 . A smoking article in accordance with  claim 1 , wherein the grooves ( 20 ) at the circumference have a width of 1 to 3 mm. 
     
     
         10 . A smoking article in accordance with  claim 9 , wherein the grooves ( 20 ) at the circumference have a width of from 1.5 to 2.5 mm. 
     
     
         11 . A smoking article in accordance with  claim 1 , wherein the filter plug ( 16 ) comprises filter tow made of cellulose acetate. 
     
     
         12 . A smoking article in accordance with  claim 1 , wherein the filter plug ( 16 ) contains additives selected from the group consisting of activated charcoal, zeolites, Duolite, flavor modifiers or combinations thereof. 
     
     
         13 . A smoking article in accordance with  claim 1 , wherein the tipping paper ( 22 ) is porous. 
     
     
         14 . A smoking article in accordance with  claim 1 , wherein the tipping paper ( 22 ) is provided with ventilation openings ( 24 ) by mechanical or electrostatic means or by laser beams. 
     
     
         15 . A smoking article in accordance with  claim 1 , wherein the plug wrap of air-impermeable material is provided with ventilation openings. 
     
     
         16 . A smoking article in accordance with  claim 15 , wherein the ventilation openings are provided by on-line machine perforation. 
     
     
         17 . A smoking article in accordance with  claim 1 , wherein the degree of ventilation provided to the smoking article by the tipping paper lies between 30% and 80%. 
     
     
         18 . A smoking article in accordance with  claim 1  wherein the degree of ventilation provided to the smoking article by the tipping paper lies between 40% and 70%.