Determining Box Compression Strength
The Mullen, or burst test, was the original test method used to determine box compression strength. Mullen measures the force required to puncture the side wall of the box. Although this test is good for determining how the box reacts when dropped or hit from the side during handling, it isn’t quite as useful in determining compression strength when stacked on top of one another.
Box Compression Test (BCT), however, is valuable in determining the strength of a corrugated box with a load under controlled conditions. During transportation or warehouse storage, boxes can encounter a variety of environmental conditions and pressures. Fluctuations in temperature and humidity, handling, pallet patterns, pallet deck board spacing, and overhang can all impact box performance.
Determining the impact of these conditions on box strength is sometimes difficult, but can be estimated if the original box dynamic compression strength is known. Using the multipliers in the chart below, you can estimate a maximum safe stacking strength. Knowing the target compression strength will also help your box designer determine the proper corrugated materials combination to use for optimal design to protect your product(s).