Process and device for the formation of directly-formed cellulosic webs

1. A process for manufacturing cellulose-based webs which are directly formed from lyocell spinning solution comprising:

a. employing an extrusion device capable of extruding and extending a plurality of lyocell solution threads, arranged in one or more rows to form a curtain,

b. washing the lyocell solution threads with a continuous line of spray of a first wash liquor from spray nozzles, slits, rotating nip rollers or rotating discs in a first washing zone directly after extension and prior to web formation, whereby partially coagulated cellulose filaments are formed,

c. laying the partially coagulated filaments on a web forming device in a web forming zone, wherein the web forming device has porosity sufficient to allow a gas stream and the first wash liquor to be extracted-to form a web,

d. washing the web in a second washing zone with a washing device that includes multiple washing modules, wherein each washing module comprises a wash liquor supply box comprising two chambers and an outlet slot which applies a second wash liquor to the web as liquor curtain over the full width of the web at a controlled rate and temperature in such a way as not to damage the web and the coagulated filaments, and

e. dewatering the web,

wherein the process can operate at line production speeds from 5 m/min to 1000 m/min, and

wherein the first wash liquor and the second wash liquor is capable of removing solvent.

2. The process of claim 1 , the continuous line of spray is a curtain, an aerosol or a mist through the spray nozzles, slits, rotating nip rollers or rotating discs.

3. The process of claim 1 , wherein the first wash liquor used in step b is either the second wash liquor from a washing module in the second washing zone or supplied independent of the second wash liquor in the second washing zone.

4. The process of claim 1 , wherein permeability of the web forming device is selected to enable passage of the gas stream and the first or the second wash liquor between 4,000 and 15,000 m 3 /m 2 /h at 100 Pa pressure difference.

5. The process of claim 1 , wherein the washing device is operated in counter-current mode with the second wash liquor added at a furthest downstream washing module.

6. The process of claim 1 , wherein the liquor curtain is a uniform, closed liquor curtain.

7. The process of claim 6 , wherein the dewatering step occurs after the web has an adequate residence time per washing module for the second wash liquor to act.

8. The process of claim 7 , wherein the adequate residence time per washing module is from 0.06 to 120 sec.

9. The process of claim 7 , wherein each washing module of the washing device comprises essentially the same design and the same residence time per washing module.

10. The process of claim 1 , wherein one or more of the washing modules has the capability to recirculate wash liquor internally to increase wash liquor solvent concentration.

11. The process of claim 1 , further comprising providing a finish application or in-line hydroentanglement to the web.

12. The process of claim 1 , further comprising admixing a material to the web by dissolving or dispersing said material in a fluid of a hydroentanglement step.

13. The process of claim 1 , wherein said web is attached on one or both sides to a layer of a further material.

14. The process of claim 1 , wherein the first wash liquor is water/amine oxide mix or another liquid capable of removing solvents.

15. The process of claim 1 , wherein the second wash liquor is water/amine oxide mix or another liquid capable of removing solvents.

16. The process of claim 8 , wherein the adequate residence time per washing module is from 0.12 to 12 sec.

17. The process of claim 16 , wherein the adequate residence time per washing module is from 0.24 to 6 sec.

18. The process of claim 13 , wherein the further material is selected from the group consisting of a fiber-, film- or web-layer.

19. The process of claim 1 , further comprising:

e. collecting the web or transferring the web directly to further processing stages.

20. The process of claim 1 , wherein the first and second wash liquor are the same.

21. The process of claim 1 , wherein the first and second wash liquor are different.