The corrugated board is used globally as the most important packaging material. Due to its features such as weight ratio, suitability for marketing purposes, storage costs etc. along with easy utilisation and recycling abilities, production of the corrugated board has increased to the manifold. With the increase in interest for packaging medium, there is an increase in demand for information on its manufacturing and converting. The increasing range of corrugated products along with technical progress has laid down various requirements for a continuous refreshment of knowledge in several technical fields.
ECT (Edge crush test) is conducted according to TAPPI and ASTM standards. The edge crush resistance is an important feature of the corrugated board. Edge crush strength is measured in kN/m.
Method to conduct the test:
- A rectangular sample of sample material i.e. 25mm ±0.5mm parallel to the flutes and 100mm (±0.5 mm) perpendicular to the flute orientation is placed between the two plates.
- Pressure is applied to the sample till it fractures.
- The maximum pressure that a sample can bear is recorded
Another test is FCT (Flat crush test) is conducted using Flat Crush Tester. This test is conducted according to international standard. This test method is suitable to flat crush resistance for two or three ply corrugated boards. It does not suit for a board with more plies. It is expressed in kPa.
Method to conduct the test:
- The sample is cut from the corrugated board
- The pressure is applied perpendicularly to the surface until the corrugated medium is fractured.
- The maximum force is recorded
Usually, the result depends on the flute type and the corrugated medium features. This is applied to know the characteristics of the ply of the corrugated board.
The test is performed using Edge crush tester. Presto is one of the leading supplier and manufacturer of this testing machine. It can perform all the three types of tests i.e. edge crush test, ring crush test and flat crush test.
Edge Crush Test Machine determines the compressive strength of the sides of packaging boxes. The machine can be used to compare the quality and strength of corrugated boxes. It measures the strength using McKee’s formula where compression strength equalises to k. ECT x T x Z. K being constant. ECT is the edge crush value, T is the thickness of the CFB board (Wall thickness) and Z is the perimeter of the box.
