LINEAR BEHAVIOUR OF ONE-SIDE COATED PAPER: ANISOTROPY

The research work presents the study results of anisotropy of one-side coated papers for the purpose of offset printing. Through technological processes, e.g. paper production, finishing, coating, printing, paper becomes more homogeneous, which shows an equal transformation of mechanical tension forces. The stated is in good agreement with the measurements of paper anisotropy. The regularity is seen as the evenness of mechanical forces transmission through technological stages, e.g. calendering, coating, winding, printing etc. The processes of paper finishing do not influence paper anisotropy significantly; moreover, it remains preserved through the entire production and post-production, or it even slightly lowers after offset printing, which means that the findings presented in this study can help to better understand paper anisotropy before and after printing. Anisotropy and paper fibre connectivity in the paper core structure were studied and verified by several research methods, i.e. sonic velocity, SEM, MIT, tearing resistance etc, the results being in good relation with the theory of anisotropy in general.