The Strength Program allows you to evaluate the effects of a number of loading parameters and environmental conditions on the predicted individual case compression strength and on the resulting stacking height of a pallet load.
This program and the McKee formula relate to a standard Regular Slotted Container (top loading) case style.
The Case Compression Strength program uses McKee Formula for calculating initial case compression strength. As input to the calculations.
The Imperial McKee formula requires the combined board Edge Crush Test (ECT), Caliper (CAL) and Case Perimeter (PER) information.
Compression Strength = 5.874 * ECT * CAL0.508 * PER 0.492
As input to the calculations, the Metric McKee formula requires the combined board Edge Crush Test (ECT) in kN/m, Caliper (CAL) in mm and Case Perimeter (PER) in cm.
The Metric McKee formula is expressed as:
Compression Strength = 1.82 x ECT x 1.0194 x CAL0.508 x PER0.492
For more information on the McKee formula, please refer to the August 1963 issue of Paperboard Packaging,Compression Strength Formula for Corrugated Boxes by R. C. McKee, J. W. Gander, and J. R. Wachuta published by The Institute of Paper Chemistry, Appleton, Wisconsin, USA. Also reprinted in Chapter 11, Compression Strength Formula for Corrugated Board, Performance and Evaluation of Shipping Containers, George C. Maltenfort, copyright 1989.
For questions concerning compression strength of corrugated cases, two very good sources of information are Performance and Evaluation of Shipping Containers by George C. Maltenfort, Jelmar Publishing Company, Inc., 1989, and Corrugated Shipping Containers, An Engineering Approach by George C. Maltenfort, Jelmar Publishing Company, Inc., 1988.