The most important feature boxes can have is to keep your products safe throughout shipping and transportation. How then, is the safety of these boxes measured so you can be confident once they leave the warehouse? In the packaging and shipping industry, corrugated boxes use two different tests: The Mullen Rating Test and the Edge Crush Test (ECT). Ever wonder what those ratings tell you about the box? How are they different and which one is better for your specific packaging needs? Let’s take a look.
The Mullen Test (also known as the “burst test”) has widely used for most of the last century.
To test the strength of the corrugated cardboard boxes, a hydraulic testing device (called a Mullen tester) applies pressure to a flat piece of suspended corrugated. It measures the force (in pounds per square inch) required to burst that board, sometimes referred to as “stacking strength.” p
This indicates how the box might perform when handled individually and perhaps subject to rough handling as well.
Edge Crush Test
Automation enters the scene and many products are now being shipped on pallets. This means that stacking pressure on boxes (and safety concerns for goods) are increasing. To test this, the Edge Crush Test was established. This tells you how much weight a corrugated can withstand on edge.
ECT measures the force (in pounds per linear inch) required to crush a sample of board standing on an edge. The result? Compression strength of a box made from the board – basically: how much force can it withstand before collapsing.
Mullen vs Edge Crush Test
Which is right for you? The Mullen rating and ECT are simply not the same thing; they measure separate properties of a box. However, many carrier regulations overlap the two causing some confusion for shippers. Don’t assume that a specified ECT-grade box automatically provides enough bursting strength or that a well-graded Mullen box automatically gives your operation enough stacking strength.
The most commonly used boxes in the industry will be 200# Test (Mullen Burst Test) and 32 lb. ECT (Edge Crush Test). These are widely accepted as interchangeable.
It all comes down to your operation. If your main concern is protecting multiple packages from being crushed in shipping, use ECT. If your products are being shipped individually, rough handling may be a concern which means a Mullen certified corrugated box is more of a solution for you.
Hughes Packaging Consultant and Engineers Are Here to Help!
Knowing the respective ratings requires a combination of knowledge and history of testing shipments that are best suited for your specific needs. Your safest solution is to consult with a Hughes packaging consultant and engineers. We have a team of seasoned professionals that have many years’ experience in “consultative” sales. We are systems oriented, seeking to offer the client more than just low prices but in essence, a better overall method of doing things. We go beyond selling products; we provide packaging and shipping solutions.
Contact a Hughes Sales Representative at 267-409-6100 today to help you with all your shipping and packaging operation needs.