Biomechanical pulping of kenaf

Abstract

The objective of this study was to investigate the effect of fungal pretreatment of whole kenaf prior to refining on refiner electrical energy consumption, paper strength, and optical properties. We also explored the suitability of whole kenaf biomechanical pulp for making newsprint in terms of ISO brightness and strength properties. Kenaf was sterilized by autoclaving and treated with the white-rot fungus Ceriporiopsis subvermispora. Control and fungus-treated kenaf fiber was pulped by refiner mechanical pulping (RMP) and chemirefiner mechanical pulping (CRMP) processes. Pulps were then compared in terms of refiner electrical energy consumption, physical and optical properties of paper, and response to post hydrogen peroxide (H2O2) bleaching conditions. Fungal treatment of kenaf fiber saved up to 38% electrical energy consumption during preparation of RMP and CRMP compared to energy used for the control. Handsheet properties of treated (biomechanical) RMP pulp improved 60% to 80% in burst index, 40% to 45% in tear index, and 58% to 65% in tensile index compared to the control. RMP biomechanical pulp also showed a 15% to 20% decrease in brightness compared to that of control RMP. However, brightness could be raised to 62% ISO with a single-stage application of 2.5% H2O2 compared to 1% H2O2 for control pulp. Applying multistage hydrogen peroxide and hydrosulfite bleaching processes could raise the brightness level of biomechanical pulp even further. The higher strength of biomechanical kenaf pulp could eventually reduce the percentage of costly kraft pulp needed in newsprint and coated paper based on kenaf pulps.

Citation

Ahmed, Aziz; Akhtar, Masood; Myers, Gary C.; Scott, Gary M. 1999. Biomechanical pulping of kenaf. Proceedings of the 1999 TAPPI Pulping Conference : Oct. 31-Nov. 4, 1999, Orlando, FL. Volume 1. Atlanta, GA : TAPPI Press, 1999: Pages 285-290