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US 9,315,942 B2Granted
Method for pretreating cellulose pulp
AssigneeUpm-Kymmene Corporation
InventorsMarkus Nuopponen, Monika Osterberg, Janne Laine, Jaakko Pere
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Abstract
A Method of pretreating native cellulose pulp in the manufacture of nanofibrillated cellulose, and a nanofibrillated cellulose product obtainable by the method.
Claims20
A method for the manufacture of nanofibrillated cellulose, the method comprising:
- pretreating native cellulose pulp, the pretreating comprising
- bringing an aqueous suspension of native cellulose pulp into contact with an inorganic or organic acid,
- agitating the aqueous suspension of native cellulose pulp and inorganic or organic acid to obtain a pH below about 4,
- removing water from the aqueous suspension of native cellulose pulp and inorganic or organic acid to obtain solid matter,
- washing the solid matter with water, thereby forming an aqueous suspension of the solid matter,
- adding at least one water soluble salt of NH4+, alkali metal, alkaline earth metal, or metal to the formed suspension,
- agitating the formed suspension,
- adjusting the pH of the formed suspension to about 7.5 to 12 using an inorganic base,
- removing water to yield solid matter of the formed suspension, and
- washing the solid matter of the formed suspension with distilled or deionized water to yield pretreated native cellulose pulp;
- forming an aqueous suspension of the pretreated native cellulose pulp;
- and
- disintegrating the aqueous suspension of the pretreated native cellulose pulp mechanically.
10 more elements
Dependencies are inferred from the claim text.