Scope

The edge crush test (ECT) using a short column specimen is an important test for the boxmaker. Procedures for making the test are discussed in TAPPI T 811 Edgewise Compressive Strength of Corrugated Fiberboard (Short Column Test). For accurate and reproducible results these procedures should be followed in detail. A critical point of the method is cutting the test specimen with sharp parallel cuts exactly perpendicular to the faces. If cutting is by means of a circular saw, the saw blade must be small-toothed, no-set, and hollow or taper-ground. To improve the saw cut, the saw blade opening (throat plate) in the table saw bed should be as small as possible. This reduces chatter of the corrugated board as it is being cut. Knife cutters (single knife with guides or twin knife models) are also allowed in T 811. Single bevel knife blades are necessary in these cutters.

For referee purposes, the test specimen should have its edges reinforced with paraffin to prevent edge failures per T 811. Two other methods, TAPPI T 838 Edge Crush Test Using Neckdown and T 839 Edgewise Compressive Strength of Corrugated Fiberboard Using the Clamp Method (Short Column Test) may be adequate for routine control.