The effect of springback on the geometry of creases in paperboard package manufacturing

Abstract

The elastic recovery of material after deformation, known as springback, affects crease geometry which in turn influences the mechanical stability and appearance of the packaged products. This study investigates the effects of springback on the geometry of creases in different paperboard materials under varying conditions. Experimental tests were carried out for four types of paperboard materials under varying conditions and target strokes. Springback behavior was studied under normal and humid conditions. The examination of creased samples was carried out with a 3D scanner to perform springback measurements. The study evaluated mechanical properties including tensile strength in combination with tearing resistance and bending stiffness to determine material property correlation with springback. The results demonstrate that springback depends on creasing parameters, fiber orientation, and material properties. Paperboard shows anisotropic behavior, with higher springback in the cross direction compared to the machine direction. Humidity was found to reduce springback, while coating types also impact crease retention, with PET-laminated paperboard showing the minimum springback.