Response of Kenaf Woody Core to Chemimechanical Treatments: 2. The Effect of Water Retention and Swelling on Defibration ..., 2000 Pulping / Process & Product Quality Conference Proceedings

M. V. Byrd--In Part 1 of the work, the effect of soaking kenaf core in water and alkali on water retention value (WRV) and yield was determined. The work in Part II focused on relating the WRV to actual fiber swelling and then determining how the swelling affected strength development during refining. Kenaf core was soaked in alkali at various concentrations for various times and temperatures. The core samples were then primary- and secondary-refined in a commercial blender in identical fashion. Handsheets were made and tested for tensile and tearing strength. Increasing alkali concentration had a strong negative effect on swelling, while increasing temperature had a moderate positive effect. Screened yield after refining was found to be positively related to total yield after soaking. Increasing alkali concentration and temperature had a negative effect on screened yield, but increasing time did not. Increasing alkali concentration also caused an increase in the pulp freeness after primary refining. Significant differences were found between the tensile breaking length and tearing index of different samples, but the differences could not be related to changes in the process variables or to swelling or yield.