Abstract: Cellulose ester fibrillar material is produced by forming a cellulose ester dope, pumping the dope to an extrusion orifice, extruding the dope through the orifice into a region of shear and high draw in a precipitation bath containing a non-solvent for said cellulose ester maintained at an elevated temperature. The fibrillar material is preferably subjected to further treatment to reduce the particle size and set the structure by expanding voids and expelling residual solvent. Paper having a high degree of opacity is produced by incorporating the cellulose ester material to obtain light weight paper.

Abstract: Improved aerosol filters, particularly cigarette filters, are prepared by imparting a patterned surface, preferably a plurality of longitudinal grooves, to a web of a synthetic thermoplastic fibrous material, preferably a tow of longitudinally aligned crimped continuous cellulose acetate filaments, and forming the resultant patterned web into a filter of the desired form.