Reduction of carbon monoxide in mainstream cigarette smoke

Abstract

A smoking article filter is designed to reduce the amount of carbon dioxide (CO) and increase the ratio of total particulate material (TPM) to CO in mainstream cigarette smoke. The design includes a non-porous microcapillary tube centered axially within a low-density filter.

What is claimed is: 
     
         1 . A smoking article comprising a tobacco column comprising a proximal end and a distal ignitable end, the tobacco column configured to generate products of combustion comprising at least one of tar and carbon monoxide; and
 a filter segment, comprising a proximal mouth end and a distal end coupled to the tobacco column, the filter segment further comprising a tubular filter structure surrounding a non-porous microcapillary tube, the microcapillary tube centered axially within the tubular filter structure;   wherein smoke inhaled by a user at the proximal mouth end of the filter segment comprises a ratio of tar to carbon monoxide that is greater than or equal to 1.0.   
     
     
         2 . The smoking article of  claim 1 , wherein the filter segment further comprises at least one of the following: cellulose acetate, paper, and nylon fiber. 
     
     
         3 . The smoking article of  claim 1 , wherein the microcapillary tube comprises at least one of the following: a polycarbonate or other polymeric resins, including polyethylene, polypropylene, nylon, paper, and cellulose acetate. 
     
     
         4 . The smoking article of  claim 1 , wherein the smoke inhaled by the user further comprises a reduced amount of carbon monoxide as compared to smoke filtered by a solid filter of a standard cigarette. 
     
     
         5 . The smoking article of  claim 1 , wherein the smoke inhaled by the user further comprises a reduced amount of carbon dioxide and a reduced amount of tar as compared to smoke filtered by a solid filter of a standard cigarette. 
     
     
         6 . The smoking article of  claim 1 , wherein the ratio of tar to carbon monoxide is a function of at least one of the following: a diameter of the microcapillary tube, a density of the filter segment, and a degree of air ventilation of the filter segment. 
     
     
         7 . The smoking article of  claim 1 , wherein the smoke inhaled by the user further comprises a consistent ratio of tar to nicotine as compared to smoke filtered by a solid filter of a standard cigarette. 
     
     
         8 . The smoking article of  claim 1 , wherein the filter segment further comprises a heat reflective or heat absorbent material that coats or forms at least one of the microcapillary tube or the tubular filter structure. 
     
     
         9 . The smoking article of  claim 1 , wherein the filter segment further comprises at least one of the following: a fragrance, an encapsulated fragrance, polymeric beads, or carbon beads. 
     
     
         10 . The smoking article of  claim 1 , wherein a diameter of the microcapillary tube varies within the tubular filter structure. 
     
     
         11 . The smoking article of  claim 1 , further comprising a mouth piece coupled to the proximal mouth end of the filter segment. 
     
     
         12 . The smoking article of  claim 11 , wherein the mouth piece is configured to disperse smoke delivered in the user's mouth. 
     
     
         13 . The smoking article of  claim 11 , wherein the mouth piece is configured to conceal the microcapillary tube. 
     
     
         14 . The smoking article of  claim 11 , wherein the mouth piece comprises a pattern of inlets configured to control a direction or a velocity of aerosol exiting the mouth piece. 
     
     
         15 . A filter segment for use in a smoking article, the filter segment comprising a tubular filter structure surrounding a non-porous microcapillary tube, the microcapillary tube centered axially within the tubular filter structure;
 wherein smoke inhaled by a user of the smoking article comprises a ratio of tar to carbon monoxide that is greater than or equal to 1.0.   
     
     
         16 . The filter segment of  claim 15 , further comprising at least one of the following:
 cellulose acetate, paper, and nylon fiber.   
     
     
         17 . The filter segment of  claim 15 , wherein the microcapillary tube comprises at least one of the following: a polycarbonate or other polymeric resins, including polyethylene, polypropylene, nylon, paper, and cellulose acetate. 
     
     
         18 . The filter segment of  claim 15 , wherein the smoke inhaled by the user further comprises a reduced amount of carbon monoxide as compared to smoke filtered by a solid filter of a standard cigarette. 
     
     
         19 . The filter segment of  claim 15 , wherein the smoke inhaled by the user further comprises a reduced amount of carbon dioxide and a reduced amount of tar as compared to smoke filtered by a solid filter of a standard cigarette. 
     
     
         20 . The filter segment of  claim 15 , wherein the ratio of tar to carbon monoxide is a function of at least one of the following: a diameter of the microcapillary tube, a density of the filter segment, and a degree of air ventilation of the filter segment. 
     
     
         21 . The filter segment of  claim 15 , wherein the smoke inhaled by the user further comprises a consistent ratio of tar to nicotine as compared to smoke filtered by a solid filter of a standard cigarette. 
     
     
         22 . The filter segment of  claim 15 , further comprising a heat reflective or heat absorbent material that coats or forms at least one of the microcapillary tube or the tubular filter structure. 
     
     
         23 . The filter segment of  claim 15 , further comprising at least one of the following: a fragrance, an encapsulated fragrance, polymeric beads, or carbon beads. 
     
     
         24 . The filter segment of  claim 15 , wherein a diameter of the microcapillary tube varies within the tubular filter structure. 
     
     
         25 . The filter segment of  claim 15 , further comprising a mouth piece coupled to the tubular filter structure. 
     
     
         26 . The filter segment of  claim 25 , wherein the mouth piece is configured to disperse smoke delivered in the user's mouth. 
     
     
         27 . The filter segment of  claim 25 , wherein the mouth piece is configured to conceal the microcapillary tube. 
     
     
         28 . The filter segment of  claim 25 , wherein the mouth piece comprises a pattern of inlets configured to control a direction or a velocity of aerosol exiting the mouth piece. 
     
     
         29 . A method for reducing an amount of carbon monoxide in mainstream cigarette smoke, the method comprising:
 inserting a non-porous microcapillary tube axially into a filter segment of a cigarette; and   controlling at least one of a diameter of the microcapillary tube, a density of the filter segment, and a degree of air ventilation of the filter segment.   
     
     
         30 . The method of  claim 29 , wherein smoke inhaled by a user of the cigarette comprises a ratio of tar to carbon monoxide that is greater than or equal to 1.0.