Changes in pulp properties produced in mill disc refiners have been co
mpared to those produced in an Escher-Wyss laboratory refiner at equal
numbers and intensities of fibre impacts determined by the ''C-Factor
''. Similar changes in properties were found. The values for number an
d intensity of impacts were also compared to theoretical values in the
published literature, and appear to be reasonable based on our curren
t knowledge of refining.