Date of Award


Degree Name

Bachelor of Science


Paper Science and Engineering


This is a study of the effects of fractionation on total refining energy and final sheet strength. A selectifier screen was used to fractionate an.input recycled pulp into long and short fiber lengths. Each of the three pulps were refined in a PFI mill then the long and short fiber groups were recombined in the same proportion as they split and formed into handsheets. The handsheets made via fractionation were found to be no stronger, per unit energy into the refiners, than the handsheets of the unfractionated input fibers. Two interesting points, one, that each pulp consumed different energy amounts per unit time in the refiner, and two, that pulp particles which pass through linen pillowcases have no papermaking value.