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. An extrusion step using an extrusion device (1) capable of extruding a plurality of threads of lyocell solution, in particular arranged in one or more rows to form a curtain, and also capable of extending the solution threads,
• b. a first washing step performed in a first washing zone with means (7) of delivering wash liquor to the solution threads directly after extension and prior to web formation, whereby partially coagulated cellulose filaments are formed,
• c. a web forming step performed in a web forming zone with a web forming device (4) onto which the partially coagulated filaments are laid to form a web (11), wherein the web forming device (4) has porosity sufficient to allow gas stream and wash liquor to be extracted through it,
• d. a second washing step performed in a second washing zone with a washing device (5) which includes multiple modular washing modules (2), wherein
• e. each washing module (2) comprising a means (9) of applying wash liquor to the web (11) in such a way as not to damage the web structure and the coagulated filaments and a dewatering device (10) for at least partially dewatering the web (11), and
• f. a means (6) of collection for washed web (11) or transferring the web (11) directly to further processing stages, and
• g. that the process can operate at line production speeds of the formed web (11) of from 5 m/min to 1000 m/min and
• h. that the wash liquor is water, water/amine oxide mix or another liquid suitable for removing solvent.