Comparison of Two Sequences for High Viscosity Kenaf Bast Pulp Production
Wiwin Suwinarti*, Yu Wang*, Zhou Cheng**and Kazuhiko Sameshima*
*Kochi University (Japan); ** Tongji University (Shanghai)
In view of recent global environmental issues and inadequate raw fibre resources, scientists worldwide have begun to show interest in exploiting the full potential of kenaf (Hibiscus cannabinus L.) and its diverse uses. New applications of kenaf have been developed not only in the pulp and paper industry, but also in other industries. To develop a new usage of kenaf bast pulp, the pulp should be processed in optimum conditions, because it has been shown to be highly sensitive to the conditions under which wood pulping employed. A combination of ammonium oxalate pre-treatment, soda pulping under normal pressure and acidic chlorite treatment yielded an excellent pulp with extraordinarily high viscosity and highly desirable mechanical properties. On the other hand, using a sequence of acidified sodium chlorite, ammonium oxalate and 1% sodium hydroxide treatment generated good quality kenaf bast pulp for fiber length measurement, but it exhibited rather lower viscosity.
Kenaf bast fiber was treated by ammonium oxalate, sodium hydroxide and acidic chlorite at different order and conditions for each sequence. The viscosity of pulp and the paper strength properties were determined according to the TAPPI standard.
The viscosity of the first sequence (Kenaf-A) was confirm to be higher than that of the second sequence (Kenaf-B). The other kraft pulps (pine, birch and commercial kenaf bast), showed lower viscosity. The similar result also appeared on the paper strength properties where Kenaf-A is the highest. The index of tensile, burst, tear and folding endurance of kenaf-A is 87.2Nm/g, 7.2kPa.m2/g, 8.1mN.m2/g and 771times, respectively and kenaf-B is 74.3 Nm/g, 6.5kPa.m2/g., 7.0 mN.m2/g and 490 times, respectively.
(Annual Meeting of Japan Wood Research Society at Sapporo-Japan, August 2004)
