Extrusion method
AssigneeAurotec GmbH
InventorsStefan Zikeli, Friedrich Ecker
Life of this patent
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Abstract
A method is provided for producing solid cellulose filaments or films from a solution of cellulose, NMMO (N-methylmorpholine-N-oxide) and water, including pressure-extruding the solution by one or more extrusion openings and by solidifying the filaments or films in a precipitation bath. The solution is guided between the extrusion opening and the precipitation bath by an air gap, the temperature of the solution on the extrusion opening being lower than 105° C. and the pressure difference in the air gap between the pressure of the solution immediately prior to extrusion and after extrusion is between 8 and 40 bar.
Claims16
A method for producing solid cellulosic shaped articles, or films, from a solution of cellulose, NMMO (N-methylmorpholine N-oxide) and water, comprising:
- extruding the solution through one or more extrusion openings under pressure and solidifying said articles, or films, in a collecting bath, wherein a length of the solution extends between the extrusion openings and the collecting bath;
- and
- guiding the solution through an air gap with a gas flow between the extrusion openings and the collecting bath, the temperature of the solution at the extrusion openings is below 105° C. and the pressure difference between the pressure of the solution immediately before extrusion and after extrusion in the air gap is between 8 and 40 bar, wherein the gas flow is guided against the entire length of the solution extending between the extrusion openings and the collecting bath by a fan and an additional flow guide element.
A method for producing solid cellulosic shaped articles, or films, from a solution of cellulose, NMMO (N-methylmorpholine N-oxide) and water, comprising:
- extruding the solution through one or more extrusion openings under pressure and solidifying said articles, or films, in a collecting bath, wherein a length of the solution extends between the extrusion openings and the collecting bath;
- and
- guiding the solution through an air gap with a gas flow directed toward the entire length of the solution extending between the extrusion openings and the collecting bath by a fan and an additional flow guide element, the temperature of the solution at the extrusion openings is below 105° C. and the pressure difference between the pressure of the solution immediately before extrusion and after extrusion in the air gap is between 8 and 40 bar so that NMMO particle formation in the air gap is reduced.
Dependencies are inferred from the claim text.