Tob. Reporter, 1985, 112-9, p. 110, ISSN.0361-5693
Non-combustible carbonized cigarette filters
U.S. Patent 4,516,589 assigned to Philip Morris. Porous cellulosic material is contacted with a film-forming aqueous solution of an inorganic salt selected from the group consisting of alkali metal and ammonium silicates, carbonates, hydrophosphites,...