Testing Method for Incoming Sheets

Kevin asks,


Do you know of any easy way to test in coming sheets for ECT value? Currently we cut out a chunk of the sheet and send to an outside test lab for results. As you can imagine this takes several days and occasionally results come back with lower than acceptable ECT values. I am wondering if there is a simple tool we could keep machine side to test for ECT.

For a quick answer you could buy your own crush tester and accompanying accessories.

However, if you decide to go that route you may want to consider the Korutest device. It’s a more advanced methodology where you can also test the degradation losses on each one of your pieces of converting equipment. It does not require a conditioned TAPPI test lab and results are provide in 10 seconds.

One Response to “Testing Method for Incoming Sheets”

  1. katimavik86 Says:

    I would be interested to know if anyone has been able to correlate anything to anything with the Korutest device. It does not seem suitable as a quality evaluation pass/fail because it does not seem to be bothered by poor flute formation. Furthermore, the pin adhesion values have to be absolutely, positively awful before the numbers are affected.

    I thought perhaps it may have value in comparing one version of 32 ECT against another 32 ECT construction (for example) to find the “best” one, but… the “old-fashioned” method of comparing ECT, bending stiffness, and cost still seems to be the most reliable approach.

    Caliper can be tricky to monitor because the flutes bounce back (to a large extent) even when the medium has been compromised with a kink. You can’t do a 4-point bending stiffness on a finished box but, again, the Korutest only seems to register low values at the point where you can find crush with a (much less expensive) micrometer.

    I should mention that I do not have and have not used this device. I have spoken to many people who have and my “exit polls” are reflected in the comments above. I am not saying it’s worthless, but what are the right circumstances for its use?

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