Surface Crush (FCT) Tests

The two international standards based on surface crush tests are:

• ISO 3035 Corrugated board - Determination of flat crush resistance
• TAPPI T 825 Flat crush test of corrugated board (hard support method)

The ISO 3035 standard, developed by the International Standards Organization (ISO), defines a test method for determining the flat crush resistance of corrugated cardboard used in the production of shipping containers. This standard applies to single-sided and single-walled (double-sided) corrugated cardboard. Double-walled (double-double-sided) corrugated cardboard and micro-corrugated cardboard are described and are not covered by this standard. Because the endpoint of the experiment is not clearly defined or observable.

MDF (medium density fiberboard) shipping containers can be subjected to compression forces in the thickness direction as part of the manufacturing process, as well as during shipping or storage. These forces can compress the trough structure and reduce the structural integrity (stacking strength) of the corrugated material. Such crush resistance is an important indicator of the container's performance characteristics.

For the purposes of this standard,

• Flat crush refers to the maximum crushing force applied perpendicular to the surface of the ribbed structure, sustained before the structure has completely collapsed.
• Collapse refers to the point at which the sidewalls of the troughs can no longer support the load as they are subject to compression damage.
• Flat crush resistance refers to flat crush divided by the area of ​​the test piece under the test condition.

According to the TAPPI T 825 standard developed by the Technical Association of the Pulp, Paper and Conversion Industry (TAPPI), the flat crush test is a measure of the resistance of the corrugated cardboard corrugation to a crushing force applied perpendicular to the surface of the sheet under prescribed conditions. This test is applicable for single- or single-wall (double-faced) corrugated cardboard, but is not suitable for double-walled or three-walled corrugated cardboard due to lateral movement of the central lining or linings. In this method, the sample essentially rests on a rigid support and is tested at a constant deflection rate.

It is important that the force applied to the specimen is exactly perpendicular during these tests.

Our organization also provides surface crushing (FCT) testing services with its trained and expert staff and advanced technological equipment, among the numerous test, measurement, analysis and evaluation studies it provides for businesses in various sectors.