PFI Laboratory Mill
For use in the laboratory for beating of chemical pulps under standardized conditions and also for the desfibration of semi-digested raw material fibers.
A weighted and disintegrated amount of pulp is put inside the housing. This operation must be done manually, placing the pulp along the housing wall. The roll is lowered and introduced into the housing. The security cover is also put. After pushing Test button, the test initiates. The housing will turn at 710 r.p.m and the roll (with its 33 blades) at 1458± 30 r.p.m, both in the same sense. The roll exerts a pressure of 3,33 N/mm against the housing wall, where the pulp is located. This way, due to the pressure applied between the housing wall and the roll blades, the pulp is refined. The refining times vary from 2 to 10 minutes (depending on the type of pulp). After having rotated the preselected revolutions, the roll and the housing stop and the refining process ends. Finally, the roll is situated in the centered initial position and the refined pulp is extracted to measure the freeness of the pulp ºSR or CSF.