Method for manufacturing dissolving pulp
AssigneeSöDra SkogsäGarna Ekonomisk FöRening
InventorsJim Parkås, Harald Brelid
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Abstract
A method for manufacturing dissolving pulp using wood material is disclosed. The method comprises subjecting the wood material to a hydrothermal treatment using steam and/or water, digesting the wood material obtained to a pulp in a kraft cooking process; subjecting the pulp to a cold caustic extraction CCE; and dewatering, washing and pressing the pulp to get a pulp product having a carbohydrate content. The wood material can be a coniferous wood material, and whereby the mild hydrothermal treatment is performed to reach a P-factor of from 100-300, and whereby the cold caustic extraction is executed to reach a combined concentration of anhydromannose and anhydroxylose of 5 weight %, or less, of the carbohydrate content of the pulp product.
Claims15
A method for manufacturing dissolving pulp using wood material, said method comprising the steps of;
- a) subjecting said wood material to a hydrothermal treatment using steam and/or water,
- b) digesting said wood material obtained from step a) to a pulp in a kraft cooking process;
- c) subjecting said pulp to a cold caustic extraction CCE;
- and
- d) dewatering, washing and pressing said pulp to get a pulp product having a carbohydrate content,
- characterized by that
- said wood material is a coniferous wood material, and whereby said hydrothermal treatment is performed until a P-factor of from 100-300 is reached, and whereby said cold caustic extraction is executed to reach a combined concentration of anhydromannose and anhydroxylose of 5 weight % or less of said carbohydrate content of said pulp product.
Dependencies are inferred from the claim text.