NC State
J. Colley, J. de Yong and H.G. Higgins. Surface properties of hardwood papers in relation to fibres and vessels. In The Fundamental Properties of Paper Related to its Uses, Trans. of the Vth Fund. Res. Symp. Cambridge, 1973, (F. Bolam, ed.), pp 394-406, FRC, Manchester, 2018.


The surface properties of hardwood papers are determined largely by the nature of the fibres and vessel elements (henceforth referred to as vessels) and the possibilities for interfibre and fibre to vessel hydrogen bonding. Experiments with Eucalyptus species and tropical hardwoods covering a wide range of wood densities have shown that surface smoothness as well as bulk mechanical properties depend on the lateral conformability of the fibres and that the response to beating, in terms of surface smoothness, is more marked for pulps with fibres of high Runkel ratio. Effective removal of vessels from pulps was accomplished on a laboratory scale by a method based on that used by Jacquelin for flocculation studies. Vessel removal resulted in a drastic reduction in the vessel IGT pick number. A comparison between the picking tendency of two eucalypt pulps with similar external fibre and vessel dimensions, similar vessel concentrations, but with greatly different fibre lumen diameters, indicated that the bonding strength between fibres and vessels is an important factor in picking, as well as vessel size and concentration. Laterally conformable fibres from low density woods can provide the necessary fibre-to-vessel bonding. Beating has a very pronounced effect in reducing pick number and the question arises whether breaking up of the vessels or improved bonding is mainly responsible. The wider use of hardwood resources for fine papers, particularly for offset printing papers, depends on the surface properties that can be attained.

Download PDF