Abstract: A method and an apparatus for predicting a score-line cracking propensity of a multi-ply substrate. The method includes the steps of: bending the multi-ply substrate; acquiring tensile load data from the multi-ply substrate during bending; and computing a material property of a top ply of the multi-ply substrate based on the acquired tensile load data. The material property must show a strong correlation to the score-line cracking propensity of the multi-ply substrate. The material property which is computed is the energy consumed in plastic deformation of the top ply during the fracture process. The measurement results can be used to predict score-line cracking propensity in multi-ply board systems, such as multi-ply paperboard.

Abstract: A method and an apparatus for predicting a score-line cracking propensity of a multi-ply substrate. The method comprises the steps of: bending the multi-ply substrate; acquiring tensile load data from the multi-ply substrate during bending; and computing a material property of a top ply of the multi-ply substrate based on the acquired tensile load data. The material property must show a strong correlation to the score-line cracking propensity of the multi-ply substrate. The material property which is computed is the energy consumed in plastic deformation of the top ply during the fracture process. The measurement results can be used to predict score-line cracking propensity in multi-ply board systems, such as multi-ply paperboard.