Out-of-plane shearing characteristics of coated paperboard

The out-of-plane shearing characteristics of a paperboard by a straight punch and dies are important to estimate the paperboard stripping performance. In this paper, in order to reveal the die clearance effect and the feed velocity effect on the sheared end-profile of the paperboard, a precision shear testing device was developed. The shear cutting of the paperboards was experimentally carried out by varying the die clearance and the feed velocity of punch. Through this work, it was confirmed that (1) the load response had two kinds of transition gradient before passing through the maximum load point; (2) the shearing performance was classified with the normalized indentation depth d/t=0.1∼0.2 into an out-of-plane shear mode and a combined shear mode. Here, the combined mode was composed of out-of-plane bending and in-plane tensile deformation; (3) the surface layers of paperboard were observed with a de-lamimated state using an image processing of side-view flow deformation of the paperboard. Furthermore, (4) the shear strength was discussed with the orthotropic properties of the paperboard.