The fines of mechanical and chemical pulps have a character very distinct from their respective fibre fractions. The fines can be regarded as a special furnish component and the optimum quality and percentage of fines in the sheet depends on the properties of the fibre fraction used. An addition of suitable fines can improve remarkably the properties of a printing paper.
This paper deals with the structural, optical and strength properties of fibre networks, as influenced by fibre coarseness and the introduction of different types of fines. The response of these networks to calendering is also studied. Fibre fractions of different coarseness and lignin content are used. Confocal laser scanning microscopy (CLSM) is used to determine the changes in the structure and microscopic roughness of the sheet.