LIGNOFIBRE (LGF) ORGANOSOLV PROCESS FOR PRODUCING DISSOLVING PULPS

The potential of different organosolv processes, based on use of acetic acid as the cooking solvent, to produce high-quality pulps meeting the requirements for dissolving pulps was evaluated. The Lignofibre (LGF) and Formacell processes produced pulps with acceptable delignification degree at short cooking times. Both of these pulps were readily bleachable to high brightness with short ECF and TCF bleaching sequences. The pulps met most of the general requirements for dissolving pulps, i.e., high cellulose and low lignin, hemicellulose, ash, and metal contents as well as adequate viscosity and R18. The reactivity of cellulose, as determined by the Fock method, was very high. The LGF pulp was shown to be a potential raw material for regenerated cellulose applications, where high viscosities together with high cellulose reactivity are required, and where the hemicellulose content is not critically important, such as the cellulose ether grades.