IMPROVING SOFTWOOD MECHANICAL PULP PROPERTIES WITH OPHIOSTOMA-PILIFERUM

Earlier reports showed that chip treatment with a nonstaining fungus, Ophiostoma piliferum, reduced pulp extractive contents. Producers usin g the fungus have seen increases in paper strength properties. In the present work, reductions in extractive content of loblolly pine (Pinus taeda) wood meal by 1-, 3-, and 5-week treatments were similar to tho se reported earlier. Chips from the same wood were refined with a Spro ut-Waldron atmospheric refiner to various CSF levels. Resultant pulps were used to make handsheets. Pulp and handsheet properties were evalu ated using TAPPI Test Methods. Tensile strength increased marginally, while tear strength increased significantly. Treated chips yielded pul ps with increased fiber lengths and decreased fines contents. During a pilot-scale trial to examine fungal treatment effects, southern pine chips were treated with O. piliferum and aged for 5 weeks. Control chi ps were frozen during this time period. Chips were refined in a pressu rized double-disc refiner, while an atmospheric double-disc refiner wa s used for secondary refining. TAPPI standard handsheets produced from O. piliferum-treated chips exhibited tensile and tear strengths great er than controls. Refining energy consumption decreased with fungal tr eatment. Increased fiber lengths and decreased fines contents were not evident in the pilot-scale pulps. Increased strength properties may r esult from greater intrinsic fiber strength and increased bonding.