Study on the Influence of OCC Pulp Fractionation on Paper Properties

In this investigation، paper strengths from feed stock، refined and unrefined stocks were studied after OCC pulp fractionation and handsheet production. For this purpose، OCC pulp was fractionated by pressure screens into long and short fiber fraction. Then، feed stock and long fiber fraction were separately refined using a laboratory refiner. To produce a «recombined stock»، the long fiber pulp fraction and short fiber pulp fraction were mixed with each other. Consequently، strength properties of the recombined stock were measured and compared with those of unrefined and refined feed stocks and also with other fractions of pulp. Results indicated that overall strength properties of refined feed stock papers were higher as compared with the recombined stock paper. Also we observed that Tear index of the long fiber fraction، was higher than other pulp fractions. Tensile، Burst and SCT indexes of refined long fiber fraction were higher rather than other fractions. In addition Tensile، RCT and Scott bond indexes of refined feed stock were higher than other pulp fractions. Generally، results showed that، fractionation and recombination process is not a suitable and useful method for OCC pulp and paper strength improvement but OCC pulp refining is a better method to increase OCC pulp and paper strengths.