Specific cellulose acetate fibre cigarette filter - contg. aluminium hydroxide of a specific hydrargillite form pref. incorporated via spinning soln

A filter for tobacco smoke is made of cellulose acetate fibres contg. aluminium hydroxide which contains 80% of a crystalline constituent having a monoclinic-pseuclohexagonal structure with a specific surface of 4-15, pref. 5-9 m2/g. The principal patent describes the use of the above aluminium hydroxide deposited on the surface of cigarette filters. This deposition however requires a separate operation requiring supervision and means for handling powder. It has been found that the material hen incorporated in the fibres is still more effective than other known materials in absorving power.