Relationship between structural parameters and water absorption of bleached softwood and hardwood kraft pulps
The influence of porosity, relative bonded area and air permeability on water absorption of unbeaten and beaten bleached kraft pulps from different wood species used for tissue paper production was investigated. The water absorption was determined by four different methods such as absorption of water after immersion, initial water absorption, water absorption capacity and saturation rate with water. Linear dependences between water absorption parameters and the structural parameters of individual pulps as well as all tested pulps were obtained. The correlation coefficients obtained within individual bleached kraft pulps were from 0.95 to 1.00 and within the whole group of pulps were from 0.86 to 0.98. Relative bonded area and air permeability were found to be the most suitable parameters for predicting of initial water absorption and saturation rate with water.