refiner in a second refining step which was carried out under atmospheric conditions in a 20 34 refiner i e at temperatures below the softening temperature of lignin the freeness was lowered to an interesting range for printing paper pulps the refiner speed in this case was 1500 rpm the effect of the varying conditions on energy consumption and light scattering capacity appears from fig7 and 8 which show freeness as a function of energy consumption and respectively light scattering as a function of freeness shows that the energy consumption is considerably higher when the tmp process is initiated with a refining step at a temperature above the softening temperature of lignin than that obtained with conditions according to the invention compare fig1 shows that the light scattering coefficient is considerably lower when the tmp process is initiated with a refining step at temperatures above the softening temperature of lignin than that obtained with conditions according to the invention compare fig6 the pulps produced according to the invention therefore are clearly most suitable for use as printing paper pulps where just the light scattering coefficient must be sufficiently high for achieving the desired optical properties the example described proves clearly that mechanical pulp can be produced with the conditions of the invention at low energy consumption at the same time as essential properties like shives content long fiber content tear strength tensile strength and light scattering meet high requirements on this type of pulps the energy consumption at the production of newsprint for example can be reduced by about 40 compared with conventional manufacturing methods in the process according to the invention chemicals can be added advantageously after or during the first refining step in order to avoid.