Thermomechanical pulp from jack pine

This study reports on an extensive series of pilot plant trials on jack pine thermomechanical pulp, including investigations of fibre properties, carried out to determine the nature of the issues associated with its use. Jack pine contains coarse fibres, even in juvenile wood, which showed a poor ability to absorb energy and to develop without cutting under conventional levels of refining intensity compared to spruce. The fibre length could be preserved at extremely low intensity, but then the energy needed to reach a given freeness became excessive.