LOW-RESIDENT, HIGH-TEMPERATURE, HIGH-SPEED CHIP REFINING

摘要

A method for refining lignocellulose-containing material into pulp in a primary refiner, preferably a disc refiner (32). The material is preheated (20, 22, 24) to a temperature greater than the glass transition temperature of the lignin in the material. The material is held at this temperature for a time interval under one minute, preferably in the range of 10-30 seconds. The heated material is then subject to high intensity refining in the refiner to produce pulp. The resulting pulp has a high quality which affords great flexibility in secondary refining (44). The preheat retention interval can be adjusted to emphasize different objectives, such as reducing total specific energy (Fig. 2) or increasing strength properties (Figs. 3 and 4).