بهبود ويژگي هاي نوري خمير سوداي باگاس با استفاده از رنگبري تكميلي به وسيله هيدروسولفيت سديم

Improving Optical Properties of Soda Bagasse Pulp Utilizing Complementary Bleaching with Sodium Hydrosulfite

Soda bagasse pulp was bleached, using sodium hypochlorite and sodium hydrosulfite sequence or vice versa (reverse sequence). The optical behavior of the bleached pulps was investigated through optical and thermal accelerated aging of the handsheets. Some characteristics such as brightness (R:), lightness (L*), yellowness (b*) and greenness (a*) factors as well as absorption and scattering coefficients of light before and after aging were assessed. Also, in this study, the effect of consistency (per cent) of pulp and Fee+ ion and a chelating agent (EDTA) on yellowing of paper was determined. The results indicate that application of a reductive bleaching stage after oxidative treatment of the pulp will cause more brightness stability as compared to the reverse sequence.