Treatment of cigarette sidestream smoke to remove visible smoke particles, aerosols and to convert gases with off odours

摘要

Described is a cigarette sidestream smoke treatment material made from a sheet of non-combustible active components provides a porous structure capable of treating sidestream smoke. The treatment material, as used in combination with a cigarette, provides a low sidestream smoke emitting cigarette unit. The material has a porosity that encourages a conventional free-burn rate of a conventional cigarette. The material may comprise a sorbent capable of sorbing components of the sidestream smoke, and an oxygen storage component which releases oxygen at free-burn rate temperatures to ensure that conventional free-burn rate is maintained and to enhance the oxidation treatment of the adsorbed non-aqueous components. Preferably, an oxidation catalyst is included in the material and most desirably the oxygen storage component may also function as the oxidation catalyst. Particularly preferred materials that perform the dual function are oxides of cerium. In Figure 1 the application of the treatment material is shown as a cigarette unit (10). The cigarette unit is adapted by the treatment material to emit very low levels of sidestream smoke and preferably no visible sidestream smoke. The unit comprises a conventional cigarette (12) with a tobacco rod (14), which is wrapped in conventional cigarette paper (16). The unit includes a filter tipped portion (18) that co-operates with the tobacco rod (12) in providing the usual filtration of mainstream smoke. The treatment material may be used in the shape of a tube (20) which surrounds or encompasses the cigarette (12). The tube (20) is in substantial contact with the exterior of the cigarette paper (16), as shown at juncture (22). The tobacco rod portion (14) preferably terminates at the end (24) of the tube where the tube thickness is generally shown at (26). The tube preferably has a radial thickness in the range of 0.04 mm to 1 mm. The overall outer diameter of the tube (20) will vary depending upon the diameter of the cigarette, but can be designed in a way so as not to increase appreciably the overall size of the cigarette unit. The preferred circumferences for the cigarette unit range from 25 mm to 35 mm. This is very close to commercially available conventional cigarettes which have circumferences in the range of 20 mm to 30 mm. The filter portion (18) is also preferably of a diameter which is approximately the same as the outer diameter of the tube (20) so as to provide a finished looking cigarette unit.