relative to the weight of wood the chemical aftertreatment step is preferably performed at a temperature of from 10 u00b0 c to 150 u00b0 c more particularly from 60 u00b0 c to 120 u00b0 c it is preferably performed for a time of from 1 minute to 120 minutes preferably from 1 to 60 minutes the chemical aftertreatment step may be brought to an end by any means that stops the reaction of the chemical agents on the wood as for example by washing with water the chemical aftertreatment step may advantageously be repeated a number of times more particularly two times to four times therefore allowing the papermaking capacities of the fibers to be reinforced further after the impregnating step and the optional chemical aftertreatment step the impregnated wood is mechanically refined to give a mechanical paper pulp the mechanical refining comprises primary mechanical refining also called defibration which is intended to pulp the wood optionally followed by at least one secondary mechanical refining which is intended to develop the papermaking capacities of the fibers the secondary refining is optionally followed by one or more subsequent mechanical refining operations tertiary refining refining of wastes etc mechanical refining is preferably carried out under pressure in order to allow more selective separation of the fibers primary refining may be performed by milling or grinding the wood on a grindstone in a stream of water or in a disk refiner according to one embodiment the primary refining of the wood is performed in a disk refiner the pressure is preferably set so as to achieve a refining temperature of between 105 u00b0 c and 115 u00b0 c the pressure is advantageously from 0 5 to 5 bar preferably from 1 to 3 bar the rotary speed of.