The present invention is in the field of delignifying and/or bleaching of pulp, more in particular wood pulp. Such a process is useful in paper production. More in particular, the method relates to the use of an enzyme for delignification and/or bleaching, more in particular a bacterial laccase. Even more in particular, it provides a method for delignifying and/or bleaching of a pulp, comprising an enzymatic treatment step wherein lignin-containing pulp and a laccase are reacted at alkaline pH, wherein the laccase has an amino acid sequence according to SEQ ID NO: 1 or an amino acid sequence at least 90% identical to SEQ ID NO: 1.

The present invention is in the field of delignifying and/or bleaching of pulp, more in particular wood pulp. Such a process is useful in paper production. More in particular, the method relates to the use of an enzyme for delignification and/or bleaching, more in particular a bacterial laccase. Even more in particular, it provides a method for delignifying and/or bleaching of a pulp, comprising an enzymatic treatment step wherein lignin-containing pulp and a laccase are reacted at alkaline pH, wherein the laccase has an amino acid sequence according to SEQ ID NO: 1 or an amino acid sequence at least 90% identical to SEQ ID NO: 1.

A method of producing conifer-derived pulp fibers for paper includes a beating step of beating conifer-derived material pulp fibers in the presence of a liquid including water; and an ozone treatment step of treating, with ozone water, the beaten conifer-derived material pulp fibers.

A method of producing conifer-derived pulp fibers for paper includes a beating step of beating conifer-derived material pulp fibers in the presence of a liquid including water; and an ozone treatment step of treating, with ozone water, the beaten conifer-derived material pulp fibers.

The present invention relates to the removal of hemicelluloses from paper-grade alkaline pulp thereby upgrading the pulp e.g. into dissolving-grade pulp using a combination of enzyme treatment, hot caustic extraction and optionally one or more bleaching steps.

The present invention relates to the removal of hemicelluloses from paper-grade alkaline pulp thereby upgrading the pulp e.g. into dissolving-grade pulp using a combination of enzyme treatment, hot caustic extraction and optionally one or more bleaching steps.

There is provided a cellulose based fiber made of a i) cellulose dissolving pulp, and ii) a recycled cellulose textile, which is treated to swell the cellulose with a reducing additive and a) bleached with oxygen at alkaline conditions with a pH in the range 9-13.5 and/or b) bleached with ozone at acid conditions below pH 6, wherein the cellulose based fiber is manufactured with one selected from a Viscose process and a Lyocell process. Advantages include that the tensile strength of the fiber is improved and it is possible to manufacture improved cellulose fibers which comprise a fraction of recycled material.

There is provided a cellulose based fiber made of a i) cellulose dissolving pulp, and ii) a recycled cellulose textile, which is treated to swell the cellulose with a reducing additive and a) bleached with oxygen at alkaline conditions with a pH in the range 9-13.5 and/or b) bleached with ozone at acid conditions below pH 6, wherein the cellulose based fiber is manufactured with one selected from a Viscose process and a Lyocell process. Advantages include that the tensile strength of the fiber is improved and it is possible to manufacture improved cellulose fibers which comprise a fraction of recycled material.

The purpose of the present invention is to provide a method for producing recycled pulp fibers such that articles using the recycled pulp fibers can easily achieve a uniform whiteness and users are not prone to feel psychological resistance to articles using the recycled pulp fibers. This method is described below. The method is characterized by involving: a step for supplying, from a mixed solution supply port (32) to a treatment tank (31), a mixed solution (51) which contains superabsorbent polymers and pulp fibers derived from multiple types of used sanitary products; a step for supplying an ozone-containing gas (53) from an ozone-containing gas supply port (43) to a treatment solution (52) inside of the treatment tank (31); a step in which, by raising the ozone-containing gas (53) while lowering the superabsorbent polymers and pulp fibers in the treatment tank (31), the ozone-containing gas (53) is brought into contact with the superabsorbent polymers and the pulp fibers, and the pulp fibers are bleached to form recycled pulp fibers; and a step for discharging the treatment solution (52) from a treatment solution discharge port (33), wherein the recycled pulp fibers have a 0-10 YI with respect to a standard white plate.

A surfactant treated bleached softwood kraft pulp fiber, useful as a starting material in the production of cellulose derivatives including cellulose ether, cellulose esters and viscose, is disclosed. Methods for making the kraft pulp fiber and products made from it are also described.