ANALYSIS OF SPECKS - COMPARISON BETWEEN 2 IMAGE-ANALYSIS SYSTEMS

By means of an interactive and a low-cost image analyser specks were a nalysed, based on different substrates such as filter pads, handsheets and membrane filter sam pies. Recycled fibres from different stages o f a stock preparation plant simulated in lab-scale were examined. With both image analysers the deinkability of various stocks is identicall y classified in respect to visible specks. This is particularly the ca se with reference to the processes slushing and flotation. However, th e low-cost analyser is not in a position to identify non-visible parti cles with a size of less than 50 microns. Therefore, quantitative resu lts in respect to the amount of ink particles cannot be achieved with such an analyser when the particle size is shifted to the non-visible range (e, g. by dispersion).