Abstract: Pulp processing equipment used to produce high-quality recycled pulp with little damage to fibers, high brightness and low residual ink by means of a force selectively acting on fiber surfaces during the process of recycling waste paper is disclosed. Moreover, fiber surfaces are modified by means of a force acting on only the fiber surfaces to obtain high-quality pulp and to render harmless dirts deteriorating pulp quality. A jet system is provided having one or more nozzles for jetting an aqueous slurry containing a material comprising cellulose into a vessel.

Abstract: Pulp processing equipment used to produce high-quality recycled pulp with little damage to fibers, high brightness and low residual ink by means of a force selectively acting on fiber surfaces during the process of recycling waste paper is disclosed. Moreover, fiber surfaces are modified by means of a force acting on only the fiber surfaces to obtain high-quality pulp and to render harmless dirts deteriorating pulp quality. A jet system is provided having one or more nozzles for jetting an aqueous slurry containing a material comprising cellulose into a vessel.

Abstract: The present invention aims to produce high-quality recycled pulp with little damage to fibers, high brightness and low residual ink by means of a force selectively acting on fiber surfaces during the process of recycling waste paper. Moreover, fiber surfaces are modified by means of a force acting on only the fiber surfaces to obtain high-quality pulp and to render harmless dirts deteriorating pulp quality. A method for producing recycled pulp characterized in that cavitation is generated and used to strip contaminants deposited on fibers and ash during the process of recycling waste paper. Contaminants such as ink deposited on fibers and ash are stripped/fragmented by means of the impact force induced by collapse of fine bubbles by actively introducing bubbles generated by cavitation into a pulp suspension. A jet system having one or more nozzles for jetting an aqueous slurry containing a material comprising cellulose into a vessel.

Abstract: Wood chips having low bleachability are impregnated with a chemical liquor at a pH range of 7-12 in aqueous solution and the chemical liquor from the impregnated chips is drained, whereby extractives contained in the chips and consuming bleaching agents can be removed to improve the effect of bleaching agents in a subsequent bleaching step. Bleached mechanical pulp is prepared by defibration by primary refining—bleaching—beating by secondary refining wherein pulp fibers are washed after defibrating wood chips having low bleachability and before bleaching the pulp fibers, whereby the amount of bleaching agents used can be reduced and bleached mechanical pulp having a Hunter brightness of 45-65% after secondary refining can be obtained.

Abstract: The present invention aims to produce high-quality recycled pulp with little damage to fibers, high brightness and low residual ink by means of a force selectively acting on fiber surfaces during the process of recycling waste paper. Moreover, fiber surfaces are modified by means of a force acting on only the fiber surfaces to obtain high-quality pulp and to render harmless dirts deteriorating pulp quality. A method for producing recycled pulp characterized in that cavitation is generated and used to strip contaminants deposited on fibers and ash during the process of recycling waste paper. Contaminants such as ink deposited on fibers and ash are stripped/fragmented by means of the impact force induced by collapse of fine bubbles by actively introducing bubbles generated by cavitation into a pulp suspension. A jet system having one or more nozzles for jetting an aqueous slurry containing a material comprising cellulose into a vessel.

Abstract: The present invention aims firstly to provide a novel technique capable of preparing bleached pulp having high brightness from materials having low bleachability containing high levels of extractives and secondly to provide a technique capable of reducing the amount of bleaching agents used in processes for preparing bleached mechanical pulps.