Estimation of Fibre Orientation in Paper Products by an Image Analysis On-line System

A paper web produced under industrial conditions always exhibits an anisotropy in its mechanical properties measured in the machine and cross directions. Proper and fast information about current paper anisotropy would significantly increase the efficiency of web quality control systems and allow to produce paper with greater precision. The main objective of the work presented was to determine the possibility of measurement of paper anisotropy. The method proposed is based on the image analysis of the orientation and location of special markers – luminescent fibres – which were introduced to the structure of the paper. Studies have shown that the method of image analysis provides a detection of fibres with a satisfactory level of efficiency, thus allowing accurate examination of the anisotropy of the paper samples analysed. On the basis of experiments, it was also found that the method of image analysis proposed allows to detect fibres with an accuracy appropri ate for the problem under consideration. The invention presented has already been registered in a Patent Office as submission no. P.411294.