Process and arrangement for replacing intra-fiber liquid in fibers with a replacement liquid

Process for replacing liquid inside the fiber walls with a replacement liquid adapted to modify the properties of the fibers, comprising the following steps;

• compressing a fiber cake to such a degree that a substantial quantity of the liquid inside the fiber walls is expressed into the space between the fibers and partially out of the fiber cake, forcibly supplying the replacement liquid to the fiber cake during the compression into the space between the fibers and thus displacing the original liquid inside the fiber walls from the space between the fibers and letting the fibers expand while supplying additional replacement liquid which is thus further absorbed by the expanding fibers.

Arrangement for replacing liquid inside fiber walls with a replacement liquid comprising a device (1,4,4a,5,5a) for compressing a fiber cake in such a degree that a substantial quantity of liquid inside the fiber walls is expressed to the space between the fibers and partially out of the fiber cake, a first device (6,8,9) for forcibly supplying the replacement liquid to the fiber cake during the compression and a second device (7,14) for supplying the additional replacement liquid immediately after the device for compression arranged in an expansion area where the fibers are allowed to expand after the compression while absorbing the replacement liquid.