Characterization of Residual Ink Particles by Automated Microscopy and Image Analysis - Part I: Presentation of the Equipment, 2000 Recycling Symposium Proceedings

André Godart, Laurence Briois, Michel Dubreuil--Product development for chemical additives used in deinking and bleaching of recycled fibers requires reliable measurements of the morphology of residual ink particles at different steps of a deinking process. The development of a system using automatic acquisition of series of images by optical microscopy with a specifically designed 3-axis motorized stage, followed by computation of the size distributions weighted in count and in area in mm 2 / m 2 or ppm is presented. The different modules controlling the automatic image acquisition were programmed on the commercial software Visilog 5 from NOESIS including autofocus, segmentation with a local contrast criterion, validation and computation of granulometric values. Our image analysis system is producing reliable high quality measurements that are obtained in a short time, although these two characteristics are incompatible in comparison to image analyzers currently used for analysis of residual ink particles. The output of the system is providing morphological information of residual ink particles as size distribution graphs and statistical data. For each sample, the main added value is to show in conjunction with size distribution graphs, as well as statistical data, complementary information such as the most representative images, based on closeness criterion to the mean global measurements of the whole series.