Grant: Collaborative Research and Development Grants

Low consistency refining significantly improves the strength potential of northern softwood kraft pulp. During refining the fibres are impacted by repeated bar crossings and tthe fibre - bar interactions change the physical properties of the fibres in several ways. These morphologic changes result in increased fibre-fibre bond strength by increase the surface area of bond through fibrillation and lumen collapse. However, the complexity of these bar - fibre interaction and the resulting morphological changes are poorly understood and are known to be far from optimal. This proposed research program is aimed at ensuring that Northern SWK pulp users are extracting the optimal value after low consistency refining of this unique fibre. The specific objectives are: (1) To determine the optimal refining conditions for Northern Softwood Bleached Kraft (NSBK) pulp and pulpmixtures (Hardwood and mechanical pulps) in terms of key product properties at a given specific energy and drainage. (2) To determine the limits of low intensity refining of softwood chemical pulps used for reinforcing. (3) To develop a mechanistic model of the effect of refiner operation and design on the change in pulp properties.