Cutting characteristics of white-coated paperboard subjected to straight punch/die shearing under overlapped clearance

摘要

This paper aims to describe out-of-plane cutting characteristics of white-coated paperboard subjected to a straight punch/die shearing. Although the existence of the positive and negative clearance condition is empirically known, the features and differences between them have not been sufficiently discussed with respect to the cutting characteristics of paperboard in the past. In the experiment, overlapped punch/die clearance (negative clearance) and cutting direction were varied and investigated. A load cell and a CCD camera were installed to record the cutting load resistance and the side-view deformation of the worksheet. By using the negative clearance, it was revealed that (i) the peak point of cutting load resistance was higher than that of conventional positive and zero clearances. (ii) The worksheet was separated at a shallower indentation depth compared to the other clearance cases. (iii) Material/fiber flow at the sheared zone tended to be suppressed when using the negative clearance. This suppression seems to prevent the generation of long whisker-like dust, as well as its occurrence probability. (iv) Based on the occurrence of the whisker-like dust, a negative clearance range for generating a preferable sheared edge was revealed. Also, such clearances could be used for cutting off the worksheet in various directions.