Edge Crush Test (ECT) Explained
An edge crush test (ECT) is a testing method used to measure the durability of a corrugated board. The edge crush test (ECT) gives valuable information regarding the strength of particular board to resist crushing. Corrugate box resistance strength is measured by the edge crush test and the ability of corrugated board to resist crush is specified in edge crush test (ECT).
A Little More on Edge Crush Test
The resistance of edge crush, “R”, is measured and specified in kilonewtons per meter (KN/m) and it can be calculated as following;
R = 0.01 x F¯max, where F¯max shows the average value of maximum force and is calculated in newton.
There are many material testing methods used to measure the strength of corrugated boxes. Most techniques and procedures were used to evaluate the compression and resistance strength of a box (such as regular, single wall slotted containers, empty and top to bottom) based on several characteristics.
Simplified McKee formula:
McKee published one of the empirical methods in 1963. The method used MD, CD flexural, perimeter of box and depth of box, and board edge crush test (ECT). The formula was later on simplified and it included the board ECT, box perimeter and board thickness.
The formula of McKee to calculate the value of BCT is following;
BCT = 5.876 x ECT x square root of U x d
BCT Stands for Box Compression Test in pounds,
U denotes box outline in inch,
And d denotes thickness of corrugated board in inches.
The formula used by the McKee method to estimate the value of Box Compression Test (BCT) was the most simplified but it often gives an inaccurate estimate.
Benefits of Edge Crush Test
- Box Standards – If the producer wants to determine whether the manufactured box complies with industry rules and regulations, he would perform the edge crush test.
- Strength – The edge crush test allows manufacturers to check the strength of corrugated box.
- Material testing – The edge crush test allows the manufacture to test the quality of materials used in the production of corrugated boxes.
References for Edge Crush Test