Filter tow and method for its manufacture as well as tobacco smoke filter element and method for its manufacture

Abstract

A filter tow of cellulose acetate filaments and/or cellulose acetate staple fibers, has at least the surface of the filaments and staple fibers consisting of a cellulose acetate having an acetyl number of less than 53%, preferably less than 49%. The method for the manufacture of the filter tow comprises the spinning of cellulose acetate filaments from a solution of cellulose acetate having an acetyl number of at least 53% in acetone, if necessary, cutting the filaments into staple fibers, and combining the filaments and/or staple fibers to a filter tow, the filaments or staple fibers being hydrolyzed so that at least the cellulose acetate at the surface of the filaments and staple fibers has an acetyl number of less than 53%, preferably less than 49%. The invention involves also a tobacco smoke filter element made from the filter tow, as well as a method for the manufacture of the tobacco smoke filter element. The new filter tow and the new tobacco smoke filter element are better biodegradable under action of environmental influences, yet their storage under conditions customary today is possible without the danger of microbiological degradation.

Dependencies are inferred from the claim text.