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

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.