Effect of the Introduction of Hybrid Larch (Larix Eurolepis Henry) Within the Jack Pine/Spruce Mixture Used in Kraft Pulping, 1998 Pulping Conference Proceedings

Cartons St-Laurent (La Tuque mill) uses a mixture of jack pine/spruce sawmill chips to produce bleached Kraft pulp. A study was conducted to look at the possibility of introducing hybrid larch chips in this chip furnish. The present work is part of this overall study, which considers the effect of the chips composition on the quality of the resulting pulp.

In the study, logs of 18-year-old hybrid larch were obtained from a provincial government plantation. They were debarked and chipped. As an experimental design approach, a simplex-centroid design augmented with three interior points, was chosen for the study.

Results show that hybrid larch chips can be used to replace in part or totally the jack pine chips in the mixture. However, when spruce is replaced, the tensile strength decreases and the tear strength increases, under similar pulping conditions. A mill trial has confirmed the results. Seeing the potential of hybrid larch, Cartons St-Laurent has planted so far more than 500,000 hybrid larches.