Microfibrillated cellulose: optimisation of production techniques

This thesis deals with the development of a microfibrillated cellulose based product from Imerys, made from wood pulp using a stirred media mill. Applications for microfibrillated cellulose are explored. Parameters for the generation of microfibrillated cellulose in the stirred media mill are tested for the formulation of a product with the greatest increase to the strength of paper. Models used in milling are applied to the milling of cellulose and calcium carbonate. Based on the models, ways of finding the most energy efficient process for future new materials and mills are explored. Improvements to models are suggested for both the general case of particle size reduction and the specific case of cellulose milling. A study of the energy transfer mechanisms in the mill and how they relate to the kinetic energy of the media is performed using Positron Emission Particle Tracking. The relationships between the distributions of media kinetic energy thus found and the products of milling are analysed. Modifications to the mill are made based upon these findings and tested. An environmental life-cycle assessment is performed of the product, which tests the overall environmental impacts of including microfibrillated cellulose as a strength aid in paper