METHOD OF PRODUCING MECHANICAL WOOD PULP FROM KINDS OF WOOD RICH IN RESIN AND THE LIKE

摘要

Fibrous material, suitable for processing into paper or cardboard, is produced by cutting timber particles into fibres in a disc mill is satd. steam atmosphere at 0.5 - 7 atm. and 110 - 165 degrees C. The timber chippings contain =50% of pine or other high resin timber, shredding to fibres is effected in sufficient water for the resultant material to have a concentration of =20% (50 - 30%) and shredding is carried out in the presence of 0.2 - 1 (0.2 - 0.4) of SO2 in the form of hydrogen sulphite, or hydrogen sulphite plus a small proportion of free SO2 in aq. soln. The quantity of bases, calc. as Na2O, is =0.4%, calcd. on the water-free substance of the chippings.