Confused about the different ways that corrugated boxes are rated? Don’t understand the difference between Mullen (also call “Burst”) and ECT? You’re not the only one. For years the corrugated industry only used the Mullen rating. Corrugated box consumers were familiar with boxes classified as 150 C, 200 C, 275 C and other similar designations. Then along came the 1980’s and suddenly there was a whole new way to rate boxes- ECT (short for “Edge Crush Test”) and we started seeing boxes classified as 32 ECT, 44 ECT, and other confusing combinations.
So what’s the difference? Simply put, Mullen boxes measure how much pressure it takes to burst or puncture the box and ECT measures top-to-bottom compression or stacking strength.
What’s best for your specific needs? If you are concerned with puncture resistance and containment strength you are best off choosing a Mullen grade box. If you are more worried about boxes crushing and issues with stacking then you’ll want to go with ECT shipping boxes.
Most corrugated box companies manufacture both types of boxes, so you can specify which type of box you are looking for. For the most part, prices between the two are pretty comparable, though generally ECT usually tends to be a little bit less expensive.