Comparison of the characteristics of alkaline-anthraquinone pulp and kraft pulp of Japanese larch

This paper systematically investigated bleaching properties of AS-AQ pulp of Japanese larch and compared the differences between AS-AQ pulp and KP pulp in order to understand physical properties of Japanese larch pulp. The results show that the whiteness of bleaching pulp can reach 73% (ISO) after three stage bleaching of general CEH, where the most effective dosages of chlorine and NaOH are 8% and 2.5% respectively.The whiteness of pulp can reach 79% (ISO) after the bleaching of C_DE_HD when the most effective dosage of chlorine is 9% and a reasonable dosage of NaOH on E-H stage 2%.Both bleaching procedures can reach 83% (ISO) with the total effective dosage of chlorine 7.9% after bleaching with D/CE₁D₁E₂D₂ and DE₁D₁E₂D₂.The whiteness of pulp can reach 76% (ISO) from 27% by a procedure of oxygen bleaching with enhanced H₂O₂ and bleaching with two stage H₂O₂ (O_PQP₁P₂).The degree of polymerization of AS-AQ pulp, whether unbleached or bleached pulp, is higher than that of KP pulp.