CMP Pulping from Populus euramericana for Newsprint Production

This study was carried out to investigate papermaking properties comparison of fast growth poplar species (Poulus euramericana) at two growing priods of 8 and 18 years for newsprint production in MWPI. This special poplar, has been selected from Safrabasteh research station in Gilan province. Selected poplar were chipping in MWPI.Based on the results of experimental tests, cooking conditions of 20% chemicals ( based on oven dry wood), cooking temperature of 160°C, L:W = 7:1 and cooking time of 90 min for 8 years poplar and 130 min for 18 years was selected in order to obtain pulping yield of about 85%. After chemical treatment of wood chips with?Na2SO3 solution the treated chips were defibrated in three stages and bleached by H2O2, refined in PFI mill to freeness of about 300 ml.CSF. Laboratory standard handsheet with gramage of 60g/m2 were made from the refined pulps. The results show that, in respect to physical and strength properties, the paper from poplar wood were superior to the paper produced from CMP pulp of the normal wood furnish (75% hornbeam + 25% beech ), except in optical property of opacity which has shown some reduction. Therefore, by making necessary changes in cooking conditions, to improve the paper opacity, it may be possible to use poplar ( populus euramericana ) as pure for newsprint production in MWPI. In applying this respect 8 years growth poplar has more priority.