Filter tow, manufacture thereof, and use thereof as tobacco smoke filter element

摘要

Described is a filter tow of cellulose acetate filaments and/or cellulose acetate fibres wherein at least the surface of the filaments and fibres consists of a cellulose acetate having an acetyl number of less than 53%, preferably less than 49%. The process for manufacturing the filter tow comprises spinning cellulose acetate filaments from a solution of cellulose acetate having an acetyl number of at least 53% in acetone, optionally cutting the filaments into fibres and collecting the filaments and/or fibres together to form a filter tow, the filaments or fibres being hydrolysed in such a way that at least the cellulose acetate at the surface of the filaments and fibres has thereafter an acetyl number of less than 53%, preferably less than 49%. The invention also relates to a tobacco smoke filter element composed of the filter tow and to a process for manufacturing the tobacco smoke filter element. The filter tow of the invention and the tobacco smoke filter element of the invention have superior biodegradability under the action of ambient influences; nonetheless, their storage is possible under the conditions customary today without any risk of microbiological degradation.