A New Method for Determining the Shear Stiffness of Corrugated Board

Amethod has been developed to evaluate the quality of the board used in the manufacture of corrugated boxes. This method can be used by the board manufacturer to monitor and minimise damage occurring during the board and box manufacturing processes. The MD shear stiffness of corrugated board has been shown to be a good measure of damage to the fluted medium in corrugated board. It has also been used as an indicator of the general performance of the corrugated box. This new method of measuring shear stiffness is based on torsional stiffness and is quick, reliable and repeatable. The torsional parameter is termed 'Dynamic Stiffness' and the instrument called a 'Dynamic Stiffness Tester' (DST). The board torsional stiffness has been shown to be directly proportional to MD shear stiffness. This paper outlines the theory behind the tester, gives typical results for a range of corrugated board grades and demonstrates the effect of various degrees of board damage.