Non-destructive Identification of Direction of Orthotrophy of Paperboard

The eigenmodes of bending vibrations of packaging materials as of a plate for various directions of orthotrophy are analyzed. The obtained results are used in the process of identification of machine direction and cross direction of paperboard. One dimensional model of tension of physically non-linear packaging materials is proposed. The displacements obtained by using this model are compared with the linear ones. Experimental investigations of longitudinal uniaxial tension of paperboard used for the production of packages were performed. Uniaxial tension was applied in the machine direction as well as in the cross direction of the paperboard. Mechanical characteristics and stress - strain relationships have been determined and are analyzed. Correspondence between the experimental and numerical results in the initial stage of deformations is determined.