Flat crush test of corrugated board (rigid support method)

The flat crush test (1) is a measure of the resistance of the flutes in corrugated board to a crushing force applied perpendicular to the surface of the board under prescribed conditions. The test is satisfactory for single-faced or single wall (double-faced) corrugated board, but not for double-wall or triple-wall corrugated board, because of lateral motion of the central facing or facings. In this method the specimen rests on an essentially rigid support and is tested at a constant deflection rate. See TAPPI T 808 “Flat Crush Test of Corrugated Board” for the procedure in which the specimen rests on a flexing support and is tested at a constant rate of loading. The test methods do not produce similar results.