Wood and Paper Properties of Vacuum Airlift Segregated Juvenile Poplar Whole-Tree Chips

Abstract

Whole-tree chips from a hybrid poplar clone (Populus 'Tristis #1') grown under short rotation, intensive culture (SRIC) were separated into three fractions using vacuum airlift segregation (VAS).The fractions were: accepts, which was predominantly a woody fraction; rejects, which contained less wood and more bark and twigs; and fines, which consisted mostly of bark particles.The raw material quality was evaluated and kraft pulp and paper properties were determined on the whole-tree chips and each VAS fraction as well as on a 50:50 mixture of the accepts:rejects fractions.A 50:50 mixture of VAS accepts and 55-yr-old mill-run jack pine was also studied.Pulp and paper properties of the whole-tree chips, the VAS accepts and rejects, and a 50:50 mixture of accepts:rejects were similar and were only slightly lower in quality than those of mature aspen chips.The 50:50 mixture of VAS accepts and mill-run jack pine was acceptable by industrial standards.These results suggest that wholetree chips from SRIC poplar stands can be mixed with conifer chips to supplement furnishes for kraft pulping.