Filter including randomly-oriented fibers for reduction of particle breakthrough

Abstract

Provided is a cigarette filter and method of making the filter. The filter includes an adsorbent dispersed within the filter and a downstream plug of randomly-oriented fibers. The randomly-oriented fibers mechanically capture adsorbent particles entrained in tobacco smoke. One or more plugs of axially-oriented fibers may also be located upstream and/or downstream of the adsorbent, and are included in an amount sufficient to adjust the length of the filter.

1 . A filter assembly for a smoking article comprising:
 an adsorbent including smoke entrainable adsorbent particles contained within the filter, and   a plug including randomly-oriented fibers located downstream of said adsorbent,   wherein said plug including randomly-oriented fibers provides reduced adsorbent particle breakthrough.   
   
   
       2 . The filter assembly of  claim 1 , wherein said plug including randomly-oriented fibers is located immediately downstream of said adsorbent. 
   
   
       3 . The filter assembly of  claim 1 , wherein said plug including randomly-oriented fibers is about 3 mm to about 10 mm in length. 
   
   
       4 . The filter assembly of  claim 1 , wherein filter assembly contains about 30 mg to about 200 mg of said adsorbent. 
   
   
       5 . The filter assembly of  claim 1 , wherein said adsorbent comprises carbon on tow, carbon paper, and/or carbon beads, granules particles, and the like in a cavity. 
   
   
       6 . The filter assembly of  claim 1 , wherein said filter assembly is a plug-space-plug filter, and wherein said adsorbent includes beaded carbon located in the space and the plug of randomly-oriented fibers includes randomly-oriented cellulose acetate fibers incorporated in the downstream plug of the plug-space-plug filter. 
   
   
       7 . The filter assembly of  claim 1 , wherein said filter assembly includes at least one plug of axially-oriented fibers upstream and/or downstream of said adsorbent and wherein said at least one plug of axially-oriented fibers is incorporated in one or more filter segments included in said filter assembly in an amount sufficient to adjust the length of said filter assembly. 
   
   
       8 . A cigarette comprising the filter assembly of  claim 1  attached to a tobacco rod, wherein an outer surface of said plug including randomly-oriented fibers is in contact with tipping paper attaching the filter assembly to the tobacco rod. 
   
   
       9 . The filter assembly of  claim 1 , wherein said adsorbent is selected from the group consisting of molecular sieve, carbon, and combinations thereof. 
   
   
       10 . The filter assembly of  claim 1 , wherein said smoke entrainable adsorbent particles range in size from about 0.1 microns to about 10 microns. 
   
   
       11 . A smoking article comprising:
 a tobacco rod; and   a filter assembly including an adsorbent including smoke entrainable adsorbent particles and plug of randomly-oriented fibers,   wherein said plug of randomly-oriented fibers provides reduced breakthrough of said particles.   
   
   
       12 . The smoking article of  claim 11 , wherein said plug of randomly-oriented fibers is located downstream of said adsorbent in the filter assembly. 
   
   
       13 . The smoking article of  claim 11 , wherein said adsorbent is selected from the group consisting of molecular sieve, carbon, and combinations thereof. 
   
   
       14 . The smoking article of  claim 13 , wherein said carbon comprises activated carbon on tow, carbon paper, and/or carbon beads, granules particles, and the like in a cavity 
   
   
       15 . The smoking article of  claim 11 , wherein said adsorbent is included in said smoking article in an amount of about 30 mg to about 200 mg and wherein said adsorbent particles range in size from about 0.1 microns to about 10 microns. 
   
   
       16 . The smoking article of  claim 11 , wherein said plug of randomly-oriented fibers includes randomly-oriented cellulose acetate fibers, polyester fibers, and/or polypropylene fibers and wherein said plug including randomly-oriented fibers is about 3 mm to about 10 mm in length. 
   
   
       17 . The smoking article of  claim 11 , wherein said filter assembly further includes one or more plugs of axially-oriented fibers upstream and/or downstream of said adsorbent and wherein said one or more plugs of axially-oriented fibers are included in said filter assembly in an amount sufficient to adjust the length of said filter assembly. 
   
   
       18 . A method of making a filter comprising:
 placing plugs of 2-up axially-oriented fibers in spaced apart relationship;   placing plugs including randomly-oriented fibers between the 2-up plugs such that cavities are formed at upstream and downstream ends of every other 2-up plug;   placing an adsorbent including smoke entrainable adsorbent particles in the cavities; and   cutting every other of said plugs of 2-up axially-oriented fibers centrally to form 2-up filter assemblies.   
   
   
       19 . The method of  claim 18 , further including attaching a tobacco rod to each end of said 2-up filter assemblies and cutting said 2-up filter assemblies centrally to form complete cigarettes. 
   
   
       20 . A method of treating mainstream tobacco smoke comprising:
 contacting said mainstream tobacco smoke with a sorbent; and   contacting said mainstream tobacco smoke with randomly-oriented fibers.