Mechanical pulps with yields of 96–98 % are produced by two different commercial processes,
in which wood is processed either in the form of logs treated in grinders, Figure 4.1 or in the
form of wood chips that are converted to pulp by mechanical work in a refiner Figure 4.2.
Wood source for mechanical pulp in Europe and Canada, where approximately 75 % of all mechanical
pulps are produced, is mainly spruce. Almost 40 % of the pulp production from wood
fibres in Scandinavia is mechanical pulp (year 2001). The mechanical pulp accounts for approximately
20 % of the total world production of pulp (year 2001).