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 element ( 14 ) comprising a filter plug ( 16 ) of homogeneous filtration material, a plug wrap ( 18 ) overwrapping the filter plug ( 16 ), circumferentially spaced grooves extending longitudinally of the filter plug ( 16 ) wherein said grooves run over the circumference of the filter plug ( 16 ), and a ventilating tipping paper interconnecting the filter element ( 14 ) to a tobacco rod ( 12 ), a number of grooves ( 20 ) being open on the side of the tobacco rod ( 12 ) and extending continuously only over a part of the length of the filter element ( 14 ), and hence not up to the mouth end of the filter element ( 14 ), which grooves ( 20 ) are axially aligned with respect to the filter axis, in to which axially extending grooves ( 20 ) ventilating air enters via overlying ventilating tipping paper, and any mouth end extending groove not being ventilated.  
     
     
         2 . A smoking article in accordance with  claim 1 , characterised in that the filtration material of filter plug ( 16 ) is homogeneous over the full length of the filter plug ( 16 ).  
     
     
         3 . A smoking article in accordance with  claim 1 , characterised in that the grooves ( 20 ) extend over a maximum of 80% of the length of the filter plug ( 16 ).  
     
     
         4 . A smoking article in accordance with  claim 1 , characterised in that the length of the grooves ( 20 ) amounts to about 40 to 70%, in particular about 55 to 65% of the length of the filter plug ( 16 ).  
     
     
         5 . A smoking article in accordance with  claim 4 , characterised in that the length of the grooves ( 20 ) amounts to 55 to 65% of the length of the filter plug ( 16 ).  
     
     
         6 . A smoking article in accordance with  claim 1 , characterised in that two to ten grooves ( 20 ) are provided.  
     
     
         7 . A smoking article in accordance with  claim 6 , characterised in that three to five grooves are provided.  
     
     
         8 . A smoking article in accordance with  claim 7 , characterised in that four grooves are provided.  
     
     
         9 . A smoking article in accordance with  claim 1 , characterised in that the grooves ( 20 ) are distributed symmetrically over the circumference of the filter plug ( 16 ).  
     
     
         10 . A smoking article in accordance with  claim 1 , characterised in that the grooves ( 20 ) are V-shaped or U-shaped.  
     
     
         11 . A smoking article in accordance with  claim 1 , characterised in that the grooves have a depth from 0.5 to 2 mm.  
     
     
         12 . A smoking article in accordance with  claim 1 , characterised in that the grooves ( 20 ) at the circumference have a width of 1 to 3 mm.  
     
     
         13 . A smoking article in accordance with  claim 12 , characterised in that the grooves ( 20 ) at the circumference have a width of from 1.5 to 2.5 mm.  
     
     
         14 . A smoking article in accordance with  claim 1 , characterised in that the filter plug ( 16 ) consists of filter tow made of cellulose acetate.  
     
     
         15 . A smoking article in accordance with  claim 14 , characterised in that the filter plug ( 16 ) contains additives such as activated charcoal, zeolites, Duolite or flavour-altering additives.  
     
     
         16 . A smoking article in accordance with  claim 1 , characterised in that the plug wrap ( 18 ) is air impermeable.  
     
     
         17 . A smoking article in accordance with  claim 1 , characterised in that the plug wrap is porous and/or provided with ventilation holes.  
     
     
         18 . A smoking article in accordance with  claim 1 , characterised in that the tipping paper ( 22 ) is porous.  
     
     
         19 . A smoking article in accordance with  claim 1 , characterised in that the tipping paper ( 22 ) is provided with ventilation openings ( 24 ) by mechanical or electrostatic means or by laser beams.  
     
     
         20 . A smoking article in accordance with  claim 1 , characterised in that the degree of ventilation of the tipping paper ( 22 ) lies between 30 and 80%, more particularly between 40 and 70%.  
     
     
         21 . A smoking article in accordance with  claim 20 , characterised in that the degree of ventilation of the tipping paper ( 22 ) lies between 40 and 70%.  
     
     
         22 . A smoking article in accordance with  claim 1 , characterised in that additional, short grooves intended as indication for the existence of the grooves ( 20 ) are provided on the mouth side of the filter plug ( 16 ).  
     
     
         23 . A smoking article comprising a cylindrical filter plug ( 16 ) of homogeneous filtration material, a plug wrap ( 18 ) for the filter plug ( 16 ), grooves ( 20 ) extending longitudinally along the filter plug ( 16 ) also impressed into the plug wrap ( 18 ), and a tipping paper for connecting the filter plug ( 16 ) to a tobacco rod ( 12 ), characterised in that all grooves ( 20 ) are open on the side of the tobacco rod ( 12 ) and extend continuously only over a part of the length of the filter plug ( 16 ), and hence not up to the mouth end of the filter plug ( 16 ) and that all grooves ( 20 ) are covered with the ventilated tipping paper ( 22 ).  
     
     
         24 . Use of a smoking article in accordance with  claim 1  for the reduction of the CO/tar ratio as a function of the filter ventilation.