The ring crush test is similar to the strip crush test in that the strength of liner or fluting is measured both in the machine direction and perpendicular to it.
The results in this test are highly dependent on proper specimen preparation. Specimen and test fixture must be exactly parallel to ensure accurate determination of the ring crush strength.
The standards for this test are ISO 12192 and TAPPI T 822.
As the ring crush test provides information about specimen buckling behavior rather than crush behavior, it is increasingly being replaced by the strip crush test.
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