화학열기계펄프 제조를 위한 목재 칩의 연화 효과 연구

Abstract

This study focused to investigate the softening effect of pine (Pinus densiflora ) chips using various pulping conditions for chemithermomechanical pulp (CTMP). In order to evaluate the softening effect of pine chips, shive contents, sulfur contents in wood chips and freeness were measured. The softening experiments were conducted by varying the mixing ratio of NaOH and Na2SO3 in order to soften the wood chips under different impregnation temperature. Under the same refining condition, addition ratios of NaOH and Na2SO3 did rarely affect the softening of wood chips. On the other hand, soaking temperature played a vital role in decreasing freeness. For sulfur contents in wood chips, 10% addition of Na2SO3 on oven-dried wood weight did have a significant impact on the increase of sulfur. In particular, higher impregnation temperature over 120°C contributed to the greater sulfur contents compared to 100°C. It can be confirmed that soaking temperature and the addition ratio of Na2SO3 had a great influence on the sulfonation of lignin. More softened chips might generate lower contents of shives in CTMP than less softened ones. In conclusions, in order to soften wood chips as raw materials for CTMP, soaking temperature must be maintained at over 100°C, and the amount of Na2SO3 played a more important role than that of NaOH. More softened chips could contribute to the reduction of refining energy.