What is Edge Crush Testing? – ECT FAQs

Edge crush testing FAQs

As one of the most common ways to test the peak load of materials like paper, board and corrugated cardboard can handle, edge crush testing is a key player in any good corrugated QA process.

Also known as ECT, this technique is very handy for working out the overall strength and durability of any packaging made from corrugates. To help you get a handle on common questions when it comes to edge crush testing, we’ve put together a selection of the most common queries.

What is the official definition of an edge crush test?

An edge crush test is a method of determining the cross-direction force needed to crush of a sample of corrugated board to the point of failure. This is especially useful for today’s lighter weight corrugated cardboards, which include recycled composites that weigh less but can withstand more pressure than their traditional counterparts.

What method is followed for edge crush testing?

ECT compresses a piece of paper or board between two rigid platens. Pressure is applied perpendicular to the direction of the boards’ flutes until the sample collapses and fails. The amount of force needed to push the sample to failure is used to determine its ECT rating.

How is an edge crush test calculated?

An ECT rating is calculated by determining the force in pounds per lineal inch of load bearing edge (lb./in) that a sample can take before failure. Get a clearer picture of how ECT compares to other testing methods in our ECT conversion chart guide.

What machines support edge crush testing?

There are a variety of highly precise machines that can help you achieve consistent ECT results. Such as the 17-40 Series Box Compression Tester, which offers high resolution load cells with accuracies better than +/-0.5% down to 1/1000th of the load cell capacity.

Which TAPPI standard test methods does edge crush testing use?

ECT uses standards TAPPI T 838 and TAPPI T 839. TAPPI T 898 can determine the edgewise compressive strength, parallel to the flutes, of a short column of single, double, or triple-wall corrugated fiberboard, in a neckdown, non-reinforced, loading edge configuration.

TAPPI T 898 relates to determining the edgewise compressive strength by measuring perpendicular to the axis of the flutes. Both can be used to predict the durability of shipping containers as well as for comparing the compressive strength of different lots of similar combined boards or for comparing different material combinations.

Are there other standards which edge crush testing uses?

FEFCO 8 is another standard for measuring the edgewise compressive strength of corrugated fiberboard in a variety of thicknesses.

All of the standards are relevant and the testing methods for each are similar, but there is a difference in the geometry of the corrugated fiberboard sample and clamps.

How do I maximise my crush tests?

For tips on making the most of your crush testing, check out our guide to maximizing crush and compression testing. We’ve also got a wealth of information about corrugated and its various testing methods in our exclusive report, ‘Your guide to quality corrugated’.

If you’re interested in the suite of corrugated testing products we explore and have on offer, we’d be happy to chat you through the processes and applications. If you’d like to find out more about edge crush testing or any other crush or compressions tests, get in touch.