The Box Maker’s Certificate (BMC) is placed on an outside bottom flap. This symbol identifies the manufacturer and serves as a symbol of compliance with the stated specifics. The stamp identifies the material and certifies the results of the Mullen Bursting Test or the Edge Crush Test.
The Mullen Bursting Test measures a box’s ability to withstand external or internal forces, and to contain the contents during handling. The test certifies that the box can withstand the stated pressure (lbs. per sq. in.) as applied by a Mullen Tester.
The Edge Crush Test measures the amount of force (lbs. per in.) needed to cause compressive failure of an on-edge specimen of corrugated board. The result is a primary factor in determining the compressive strength of a completed box.