Method in the production of dissolving pulp

In a process for producing a highly qualified dissolving pulp sheet comprising removing a substantial proportion of the hemicellulose in a pre-hydrolyzed, bleached sulphate cellulosic pulp consisting essentially of natural, non-chemically transformed cellulose and residual amounts of non-chemically transformed hemicellulose by contacting said pulp with an alkaline aqueous solution of sodium hydroxide to treat same, said solution containing 50-150 g NaOH/l, and being at a temperature of about 10.degree. to 60.degree. C., thereafter washing the treated pulp to remove sodium hydroxide and dissolved hemicellulose therefrom, and drying and pressing the washed, treated pulp to form sheets, the improvement comprising subjecting the pulp during at least a portion of the treatment step to mechanical working under a net energy supply of 15-100 KWh/ton pulp to split the primary layer, and at least the outer parts of the secondary layer, of the pulp fibers substantially without fibrillation, whereby the pulp sheet exhibits reduced swelling tendencies and improved mercerizing properties, combined with at least reduced need for dialysis of the mercerisation liquor, in subsequent viscose processing, while reducing the energy consumption in the treatment process.