Tobacco Smoke Filters

1,190,224. Tobacco smoke filters. EASTMAN KODAK CO. 1 Aug., 1967, No. 35205/67. Heading A2C. [Also in Division C3] A tobacco smoke filter comprises a filter medium containing cellulose acetate particles having a particle size in the range of 20 to 60 mesh (U.S. sieve), a surface area of at least 15 square metres per gram, and a bulk density in the range of 1.5 to 4.0 pounds per cubic foot. The particles are produced by precipitating cellulose acetate from an acetic acid solution to give a fibrous flocculent cellulose acetate which produces, on drying, particles having hairy protrusions. In the examples, the cellulose acetate particles form the middle component of three component filters, the end components of which are either both of cellulose acetate fibres bonded with 6% triacetin or one of the components consists of these bonded fibres and the other of pleated tissue paper.