Process for making filter tow

US8308624B2 · kind B2 · utility

Assignee

• CELANESE ACETATE LLC · US

Inventors

• John Travers · Goldberg, DE
• Craig Day · Derby, GB
• Andrew John Banks · Derby, GB

Key dates

• Filing date: Aug 25, 2006
• Grant date: Nov 13, 2012
• Expiry date: Aug 15, 2027

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A24D3/16
• WIPO field: Other consumer goods
• WIPO sector: Other fields

Abstract

A method of preparing a crimped tow of cellulose acetate filaments comprising the steps of: a) providing cellulose acetate dope b) forming filaments (23) from the dope c) applying at least one additive to the filaments d) crimping the filaments to form a crimped tow wherein the at least one additive is capable of removing a component from cigarette smoke. Preferably, the component is a Hoffmann analyte. The additive may comprise a solution, liquid, emulsion or particulate material or combinations thereof. Preferably, the additive comprises an acidic compound or an alkaline compound. The additive may comprise malic acid, potassium carbonate, citric acid, tartaric acid, lactic acid, ascorbic acid, polyethyleneimine, cyclodextrin, sodium hydroxide, sulphamic acid, sodium sulphamate, polyvinyl acetate and carboxylated acrylate, carbon, silica, zeolite, clay, alumina, metal, molecular sieves or an ion exchange resin. The product tow can be processed on standard equipment to make efficient filter rods from which cigarette filter tips can be made which give significantly increased and selective retention of key smoke constituents.