Flat crush tests (FCT) are performed according to DIN EN ISO 3035 or TAPPI T 825. In the flat crush test, a single-flute corrugated cardboard specimen is loaded perpendicular to its surface. The resistance this corrugated board presents to the force provides an indication of its behavior during processing and in use. It is important that force application to the specimen is exactly perpendicular during these tests.
Depending on individual flute heights, the highest flutes collapse first, then the middle ones, followed by the remaining flutes at the end of the test.
The crush energy and curve provide indications of the level of any predamage which may be present, since the curve is fundamentally different if the cardboard has been subjected to predamage.
If the corrugated cardboard has been predamaged, the curve is fundamentally different. The crush energy and curve provide indications of the level of any predamage.
Flat crush test (FCT) with Zwick
Precision-guided compression plates ensure extremely high lateral stiffness, guaranteeing reproducible test values.
The compression plates are suitable for the ring crush test (RCT), the flat crush test (FCT), the edge crush test (ECT) and the corrugating medium test (CMT).
Modern miniature flutes tend to collapse only under forces greater than 10kN, requiring extremely high lateral stiffness in the compression plates. Suitable plates are available from Zwick for these applications.
A circular cutter is used to ensure accurate specimen preparation.