Paper making and fiber liberation – Processes of chemical liberation – recovery or purification... – Mechanical defibration in the presence of heated gas or gas...
Patent
1998-07-01
2000-12-26
Nguyen, Dean T.
Paper making and fiber liberation
Processes of chemical liberation, recovery or purification...
Mechanical defibration in the presence of heated gas or gas...
162 28, 162 68, 241 28, 241 29, D21B 114
Patent
active
061653179
ABSTRACT:
A method for refining lignocellulose-containing material into pulp in a disc refiner comprises preheating the material to a temperature greater than the glass transition temperature of lignin in the material, and holding this temperature for under one minute. The heated material is then subject to high speed refining in a disc refiner to produce pulp. The resulting pulp may then be subject to secondary refining steps to produce paper quality pulp. The preheat retention time is preferably in the range of 5-30 seconds, and can be controlled as a process variable to optimize energy savings, pulp strength, and optical qualities. High quality pulp can be obtained with preheat at high temperature and low retention time, followed by primary refining at disc speed of at least 2300 rpm.
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Andritz Sprout-Bauer, Inc.
Nguyen Dean T.
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