Bond Strength of Oxygen Delignified Hardwood Kraft Pulps, 1996 Pulping Conference Proceedings

V.R. Snowman, H.B. Kwon, B.J.W. Cole, J.M. Genco - University of Maine

H. Jiang

Beloit Corporation

W. Miller

IMPCO Pulping Technologies

Laboratory experiments were conducted to determine the effects of high- and medium-consistency oxygen delignification on the interfiber bond strength of hardwood Kraft brownstock pulp. Interfiber bond strengths were determined using Page’s equation of tensile strength (1969) and the delamination procedure of Skrowronski and Bichard (1987). Bond strengths were measured on Kraft pulps produced using a variety of modem bleaching sequences, incorporating an oxygen stage; O(CD)EDD and O(CD)EDED. The results were then compared to those of older bleach sequences not containing oxygen; CEHDED and (CD)EDED. Additionally, the bond strength of Northern hardwood Kraft was measured on samples withdrawn following each stage of a commercial OD(EOP)DD bleach sequence. The results show that the interfiber bond strengths of both the laboratory and commercial samples increase across an oxygen stage provided the reaction conditions are not excessively harsh.