Flat Crush of Corrugated Board

Flat crush is a measure of the flute rigidity of corrugated board as it is compressed between two ridged platens. We conduct this test according to TAPPI Test Method T825. It is largely a measure of the performance characteristics of the corrugating medium and is measured on a 4 x 4 inch sample of the combined board. The force-to-failure is reported in units of psi or kPa, The test is appropriate for single-faced or single-wall (double-faced) board, but not for double-wall or triple-wall corrugated board.