Abstract:
The present invention relates to a process for replacing intra-fiber liquid in fibers by a replacement liquid, comprising the following steps; compressing the fiber cake to such a degree that a substantial quantity of the intra-fiber liquid is expressed to the space between the fibers and partially out of the fiber cake, forcibly supplying the replacement liquid to the fiber cake during the compression and thus replacing the intra-fiber liquid 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. It also relates to an arrangement for replacing intra-fiber liquid in fibers with a replacement liquid comprising a device (1, 4, 5) for compressing the fiber cake in such a degree that a substantial quantity of intra-fiber liquid 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 fibers during the compression and a second device (7) for supplying 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 replacement liquid. The object of the present invention is to get rid of or significantly reduce the content of contaminating material in not only the areas between the fibers in a fiber cake but also in the fiber wall pores and the lumen and replace this liquid by a replacement liquid.
Abstract:
The present invention is a method for manufacturing a composite material having reduced mechanosorptive creep comprising the following steps: a) mixing fibers of a lignocellulosic material with a thermoplastic material where the thermoplastic material is in fiber form, b) adding the mixture made in step a) onto a wet web, thus forming a composite material and c) hot pressing of the composite material. The present invention also provides a composite material having reduced mechanosorptive creep being the manufacturing result of the method. The present invention also comprises the use of the method and the composite material.
Abstract:
The present invention relates to a process for replacing intra-fiber liquid in fibers by a replacement liquid, comprising the following steps; compressing the fiber cake to such a degree that a substantial quantity of the intra-fiber liquid is expressed to the space between the fibers and partially out of the fiber cake, forcibly supplying the replacement liquid to the fiber cake during the compression and thus replacing the intra-fiber liquid 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. It also relates to an arrangement for replacing intra-fiber liquid in fibers with a replacement liquid comprising a device (1, 4, 5) for compressing the fiber cake in such a degree that a substantial quantity of intra-fiber liquid 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 fibers during the compression and a second device (7) for supplying 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 replacement liquid. The object of the present invention is to get rid of or significantly reduce the content of contaminating material in not only the areas between the fibers in a fiber cake but also in the fiber wall pores and the lumen and replace this liquid by a replacement liquid.
Abstract:
A process for oxygen delignification of chemical pulp comprising an oxygen treatment unit operation stage in which the pulp is treated while suspended in an aqueous solution with oxygen in the presence of alkali, whereby the pulp consistency is less than 20%; more than 50 percentage by weight of the alkali consist of one or more carbonates; and the pH of the aqueous solution during the process is adapted to provide for the essential absence of bicarbonate in said solution during the treatment. Furthermore a process for the bleaching of chemical pulp comprising a peroxide bleaching unit operation stage and an oxygen delignification process of said kind.