Thuringisches Institut Fur Textil Und Kunststoff-forschung E. V.

Thuringishces Institut Fur Textil Und Kunststoff-forschung E.v.

Ostthuringische Materialprufgesellschaft Fur Textil Und Kunststoffe Mbh

Christoph Michels

Frank Meister

Birgit Kosan

Ralf-Uwe Bauer

Michael Mooz

Bernd Riedel

Andreas Diener

Eberhard Taeger

Christine Beyer

Reinhard Maron

Klaus Berghof

Horst Kramer

A method for the production of cellulose fibers or filaments from cell material, by the dry-wet extrusion method with aqueous amine oxides, in particular, N-methylmorpholine-N-oxide as solve is described comprising the following steps: a) dispersion of a cell material, or a cell material mixture with a cuoxam DP from 250-3000, in aqueous amine oxide, b) transformation of the obtained dispersion, by water evaporation with shear, at elevated temperature, into a homogeneous solution with a zero shear viscosity of 600 to 6000 Pa&#xb7;s and a relaxation time of 0.3 to 50 seconds all at 85&#xb0; C., c) feeding the solution to a spinning jet, previous to which it is passed through flow chamber prior the jet(s), in which the retention time at the spinning temperature, d) forming the solution into at least one capillary in each spinning jet, drawing the capillary(ies) from each jet through anon-precipitating medium and then precipitating the cellulose fibers on drawing through a precipitating bath and e) at the end of the precipitating bath section drawing off the fibers by deflecting the precipitation flow. In stage d) the capillary bundle(s) are treated with a gas flow, just before the entry thereof into the precipitating bath, at an angle &#x3b1; to the capillary flow, wherein 45&#xb0;&#x3c;&#x3b1;&#x3c;90&#xb0;.

Method and device for the production of cellulose fibers and cellulose filament yarns

A method and a device for the continuous, single-step production of a homogenous solution of cellulose in hydrous aminoxides on the basis of cellulose and aqueous aminooxides, preferably N-methylmorpholino-N-oxide (NMMO), at temperatures in the range of from 50 to 130&#xb0; C. under a vacuum and water evaporation. The cellulose and the NMMO are dosed separately to the device, mixed while sheared, the water is evaporated until the mixture is dissolved, the solution is homogenized and directly fed to the consumer via screw conveyors, pumps and filters.

Method and device for the continuous, single-step production of a homogeneous solution of cellulose in hydrous tertiary aminoxides

The invention relates to a method for producing a cellulose solution in an aqueous amine oxide, preferably N-methyl-morpholine-N-oxide, for processing to form cellulosed moulded bodies according to the Lyocell method, whereby said solution has an increased thermal stability. Cellulose is suspended in an aqueous amine oxide and the suspension is converted into the cellulose solution. The inventive method is characterised in that the base use of the cellulose used for producing the solution and of the optionally used additives is detected in a dispersion in aqueous amine oxide solution and in that the cellulose solution is formed by adding a base quantity which matches the detected own consumption of the cellulose and optionally the additives. Cellulose solutions having a stability which is essentially independent from the provenance of the used cellulose can he formed.

Method for producing a cellulose solution in an aqueous amine oxide, said solution having an increased thermal stability

Method for producing regular porous cellulose pearls, corresponding cellulose pearls and use thereof

Formed shape made of regenerated cellulose and process for its production

A process for manufacturing molded articles of cellulose, such as fibers films, which includes (a) providing an aqueous solution comprising cellulose in a tertiary amine N-oxide, (b) extruding jets of the aqueous solution through an extrusion die into a non-precipitating medium for cellulose, the extrusion die having nozzle passages the length L of which is in the range from 200 to 800 .mu.m and the capillary section of which has a length l in the range from 50 to 240 .mu.m and a ratio l/d of length l to its diameter d in the range from 0.5 to 2.0, the molecules of cellulose in the jets of solution being pre-orientated by the extrusion die through a shear force gradient in the nozzle passages, (c) additionally orientating the cellulose molecules by stretching the extruded jets of solution in said non-precipitating medium with a spinning stretch ratio V of linear velocity of the precipitated molded article to the linear velocity of the solution leaving the die in the range 0.5&gt;V&gt;3, and (d) precipitating the molded cellulose articles from said jets of solution by contacting with a precipitating medium without stretching. The shortened shearing section of the nozzle passages allows a reduction of the spinning pressure. The safety of the spinning operation is increased by the low spinning stretch. The stretch interval in the non-precipitating medium is reduced, and the elongation and loop strength data of the spun fibers are improved.

Process for manufacturing molded articles of cellulose

Growing community of inventors

Rudolstadt, Germany

Christoph Michels