HIGH-YIELD PULPING OF ASPEN WOOD - RELATION BETWEEN PULP PROPERTIES AND FIBER CHARACTERISTICS BY MULTIPLE LINEAR-REGRESSION

High-yield pulps have been obtained by means of steam explosion pulpin g. This process was carried out as follows: 1) chips soak impregnation (60 degrees C, 24 h, L/C = 6) in solutions containing 8% Na2SO3 and a variable concentration of either Na2CO3 or NaHCO3, ranging from 0 to 2%; 2) cooking at high temperature (190-200 degrees C) for short time (2-1 min); 3) rapid pressure release. This work shows that mechanical properties were substantially improved when adding a second chemical t o the Na2SO3 impregnation solution. Moreover, refining energy requirem ent was significantly reduced. However, the higher chemical charge use d made the optical properties drop. In this paper, mathematical models have been proposed in order to accurately predict specific refining e nergy and paper properties from sulfonate content and pulp yield. In a ddition, the relative importance of these two parameters has been stud ied.