DELIGNIFICATION OF KHASYA PINE, PERSIAN LILAC AND BAMBOO BY SULFATE PROCESS

Abstract

Analyses of screened pulp yield. Kappa No. and lignin content from sulfate pulps of bamboo (Thyrsostachys siamensis), Persian lilac (Melia azedarach) and khasya pine (Pinus kesiya) coaking at 16% active alkali, 25% sulfidity. 4: 1 liquor to wood ratio, maximum temperature among 120° to 180° C, and H - factors of 2 ta 1,261 indicated that the rates of pulping and delignification of bamboo are the fastest but those of khasya pine are the slowest. The relationships between H-factor and Kappa No. as well as H-factor and lignin content could be logarithmic regression. The squares of regression coefficients of the bamboo and persian lilac pulps are as high as 0.8 but those of khasya pine pulp are low. The relationships between Kappa No and lignin content of sulfate pulps from the three species could be linear regression. The squares of regression coefficients were about 0.8.