RAW MATERIAL FOR PRINTING PAPER, METHOD TO PRODUCE IT AND PRINTING PAPER

摘要

The object of the present invention is a method for making mechanical pulp, such as thermomechanical or chemi-thermomechanical stock. The mechanical pul p is used as a raw material for printing paper, and its freeness value is 30-7 0 ml CSF. The stock refined by the method is screened in several stages to for m accept and reject stock portions. The wood raw material is refined at the first stage of refining at a superatmospheric pressure of over 400 kPa to fo rm a stock that has a freeness value of 250-700 ml CSF.