Formaldehyde-free environmentally friendly lignocellulosic composite from NSAB pulp. Part II

Investigations have been continuing to prepare environmental friendly lignocellulosic composites from agro-based fibers. To evaluate the possibility of spent sulfite liquor retained on neutral sulfite bagasse pulp (NSABP) as binding agent instead of HCHO-based adhesive (resol type resin) to prepare agro-based composite satisfying environmental regulations. The properties of unwashed-NSABP-composites were compared with those produced from completely washed pulp, as well as from that produced from commercial produced from resol-Asplund pulp. The neutral sulfite pulping conditions and presteaming the bagasse prior NS-pulping were optimized. The results obtained show that, the most desirable properties of agro-composite were obtained by presteaming the raw bagasse for 20 sec at 170-175 degrees C (Asplund defibrator process), followed by neutral sulfite pulping (NSAB pulp). The spent sulfite liquor retained on NS-pulp was more successful for improving the board properties than conventional adding synthetic resol resin to Asplund bagasse pulp. The chemical analyses of the obtained NS-pulps and the physico-mechanical properties of the agro-composites prepared were correlated and illustrated in polynomial equations.