The present knowledge of the manner in which pulp strength properties and papermaking are influenced by the fibre morphology of the original wood is discussed.
Fibre length has been shown to be particularly important for tearing resistance; it is of less importance for properties more related to fibre bonding. The thickness of the cell wall has an important bearing on most paper properties. Fibres with a thick cell wall give bulky, coarse surfaced sheets, whereas those with a thin wall give dense, wellformed sheets. The thick-walled fibres adversely influence bursting strength, tensile strength and particularly folding endurance, but they enhance tearing resistance, particularly when they are long. Basic density of the wood, which is indicative of cell wall thickness, may be used for assessing the value for papermaking of wood from within any one tree, from within a species or from the many species of one genus, the lower the basic density the better the general papermaking properties. In hardwoods, the vessel elements contribute little towards strength and cause trouble in printing . There is little evidence that cell diameter or the cell length/diameter ratio, in themselves, have any significant influence . The organisation of the cell wall in the individual fibres can influence paper properties. This is shown quite clearly when reaction wood fibres, which possess a markedly different organisation from that of normal wood fibres, are considered.