ALKALINE-PEROXIDE INTER-STAGE TREATED MECHANICAL PULP FROM JACK PINE (PINUS-BANKSIANA) .1. INTRODUCTION AND PULP PHYSICAL-PROPERTIES

Pilot-scale TMP and AP-TMP were produced from jack pine (Pinus banksia na) and black spruce (Picea mariana). The objective of the study was t o facilitate the use of jack pine mechanical pulps. Typically, this sp ecies has a high specific energy consumption; poor strength properties , brightness reversion and pitch problems due to the intrinsic wood pr operties. In this part of the study (Part 1), the effect of alkaline-p eroxide inter-stage treatment on pulp energy consumption and physical properties was determined. At constant specific energy consumption, sp ruce AP-TMP gave superior strength properties over all pulps. To reach a given freeness,jack pine AP-TMP used somewhat less refining energy than jack pine TMP, but there was no considerable increase in pulp str ength properties. In Part 2, the effects of the above treatment on pul p optical properties, color reversion, and extractives removal are sho wn.