BALANCE OF INK PARTICLES IN COMMERCIAL DE INKING PLANTS

More than 90% of ink particles generated by waste paper processing are invisible. Therefore image analysis is necessary for the determinatio n of ink particles at a high resolution. The knowledge about the flow oi ink particles in deinking plants is a prerequisite for quality impr ovements of deinked pulps. Improved pulps can be used in high-quality graphic papers. The evaluation of several deinking plants shows a corr elation between the results of image analysis and conventional optical parameters. The reduction oi the ink particle area in deinking plants occurs mainly in the invisible particle range and the removal efficie ncy is about 80%. Flotation mainly contributes to the reduction of the ink particle area. The efficiency of operation units such as thickeni ng, flotation and dispersion is presented and discussed with reference to the ink particle distribution.