POROUS FILTER TIP AND METHOD FOR MAKING

摘要

1447191 Ventilated cigarette tips BRITISHAMERICAN TOBACCO CO Ltd 4 Oct 1974 [9 Oct 1973] 43202/74 Heading A2C A process of making a ventilated filter tip for smoking material comprises wrapping an inherently porous plug wrap about a rod of filter material, wrapping an inherently porous tipping paper about said porous plug wrap, and adhering the tipping paper to the plug wrap by a multiplicity of randomly positioned, non porous, discrete areas of adhesive, the areas having an average diametrical dimension of between 100-500 microns (Π10%) and an average thickness of 5-19 microns (Π10%). Fig. 1 shows cigarette 10 consisting of tobacco rod 11 and filter rod 12, the latter comprising paper or cellulose acetate. Plug wrap 13 surrounds rod 12 and is inherently porous having an air-flow rate under a head of one inch water gauge of 3-18 cc/sec. Plug wrap 13 is adhered to tipping paper 14 which is also inherently porous. Tipping paper 14 encloses both rods 11, 12. A multiplicity of adhesive lakes 17 whose sizes are exaggerated are positioned on wrap 13. The area indicated generally at 18 permits passage of air through plug wrap 13 and tipping paper 14.