DE2909096

• Main Authors: RILEY, JESSE LOUIS, CHARLOTTE, N.C., US, HOWELL JUN., CARL JACKSON, CHARLOTTE, N.C., US, TROTT, DAVID WALTER, MATTHEWS, N.C., US
• Format: Patent
• Language: English
• Published: 24.01.1991
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CHEMISTRY; CIGARETTES; CIGARS; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; HUMAN NECESSITIES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES; METALLURGY; MOUTHPIECES FOR CIGARS OR CIGARETTES; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; SMOKERS' REQUISITES; THEIR PREPARATION OR CHEMICAL WORKING-UP; TOBACCO; TOBACCO SMOKE FILTERS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

A melt extrusion process for producing a low density open cell filtering element for an aerosol such as tobacco smoke from plasticized cellulose acetate. A mixture of cellulose acetate, plasticized, a volatile liquid blowing agent which is at least a partial solvent for the cellulose acetate and a nucleating agent are melt extruded under conditions wherein the melt is subjected to high shear, the loss of the blowing agent through back flow is prevented, the melt is reduced in temperature prior to extrusion and the extrudate is conditioned in a hot air chamber and then sized in a sizing die.