Paper is comprised of quasi-randomly distributed fibres, fines and different additives. The properties of paper depend on the type of fibres used, their uniformity of distribution, the amount and type of fines and fillers. It is difficult to predict how a particular component will behave in a mixture. This will depend on the form of material introduced (flocculated or dispersed) and on what kind of interactions will take place. These factors can be controlled by various wet-end strategies based on known colloidal behaviour of various additives. Thus, applying this knowledge to papermaking, one should be able to predict and control final structures of paper, which will be reflected in optical and mechanical properties. A thorough understanding of the effects of different materials, such as fines and fillers, on optical and mechanical properties of paper can only be obtained from a systematic study. Therefore, this research focused on elucidating the relationship between the nature and amount of fines and fillers and paper properties. The studies were mainly limited to papers made from thermomechanical pulps (TMP), although occasionally comparisons with other pulps were made as well.

Van De Ven, T. G. M. (Supervisor)

Garnier, G. (Supervisor)