New Concepts Accounting for Variations in the Formation of Multilayer Fiber Composite Materials

Changes in the mechanical properties of fibrous composite materials can be largely explained by quantitatively evaluating variations in the formation of their macro- and microstructure. The emergence of new technologies for evaluating composite micro- and macrostructure, including special methods for preparing samples for scanning electron microscopy, as well as the use of contemporary graphic and computational programs, results in new knowledge concerning the formation quality of such multilayer composite materials as paper and cardboard. In the present paper, a fundamentally new approach to evaluating the variations in paper and board formation is presented. In particular, the approach proposed in this study allows variations in the formation in the vertical plane of both each layer and multilayer material to be considered as a whole without thickness restrictions. The results of the study include indicators for evaluating the formation process of multilayer board and its individual layers, based on variations in floccule and fiber distribution.