Compressive Evaluation
Physical testing of corrugated fiberboard relies on a standardized compression measurement to determine the maximum load a sample can withstand before buckling. The edge crush test evaluates the rigid strength of the material when loaded parallel to the flute direction. This laboratory procedure measures the peak force that a short specimen can support when placed on its edge between two parallel plates.
It defines the structural baseline for predicting the stackability of finished shipping cases. The resulting force per unit length is expressed in kilonewtons per meter.
Loading Protocol
Executing the measurement requires a specimen to be cut with precise parallelism between its top and bottom loaded edges. During the testing cycle, a moving platen applies a compressive load at a constant rate of displacement until the sample suffers structural collapse. This compression is applied directly to the exposed flute ends.
It represents the vertical load experienced by the bottom box in a pallet stack.
Strength Correlation
Calculation of the theoretical top-to-bottom compression strength of a finished box frequently employs the McKee formula. This equation relies heavily on the ect value along with the board thickness. Designers use this relationship to choose appropriate board grades for specific storage environments.
This prevents transport failures caused by moisture-induced structural degradation.
