Abstract

The effects of pretreating wood with Pleurotus sp, a type of white rot fungus (WRF), prior to pulp production and bleaching, were investigated. The action of the WRF was studied over an 80-day period on pieces of Pinus radiata with a moisture level of 75%. Kraft pulp was then prepared in a laboratory digester, and the yield, Kappa index and viscosity were determined. After delignification with oxygen, the pulp was bleached and used to produce paper with a refining PFI to 4000 rev. Pleurotus sp has a delignifying active action and leaves a greater quantity of residual hemicellulose in biopulp compared to a control. It gives a greater pulp yield (49.7% compared to 47.5% for the control), with lower Kappa (29.1 compared to 30.3) and greater viscosity (105.3 cp compared to 80.8 cp). The bleaching process becomes more economic after its use, with energy savings of over 23%. Yields and whiteness are greater. Paper properties are improved, with TEA 47% larger and the rip index 42% greater.