Corrugated boxes play a vital part in the packaging industry. These boxes simplify storage while protecting objects from the inside. Corrugated boxes are made of corrugated cardboard, which is made from paper pulp. Three layers of kraft paper are glued together to finish the box. The centre layer of the box is made in wave shapes and is then put between two kraft paper layers to add strength and durability to the packaging box.
Now let's examine why corrugated boxes need to undergo bursting and compression strength tests.
A bursting strength test, also known as the Mullen test, measures the strength of the sides of the corrugated box in terms of the external pressure or forces it can handle. A rubber diaphragm is used to conduct the test. It puts pressure on the corrugated box walls until they can no longer bear any more stress. Gradually, it expands and bursts. Hydraulics is used for the expansion of diaphragms. This procedure helps in measuring the rough weight that a box can carry.
Bursting factor = Bursting strength x 1000/grammage (where bursting strength is measured in Kilograms per square centimetre)
The bursting strength test helps the manufacturers calculate the strength of the corrugated box so that it does not get damaged during transit. Also, the bursting strength value indicates the quality of the material used to create the corrugated box.
The box compression test, aka container compression test, calculates how much weight a box can bear before it crushes. It helps determine the stacking strength of the corrugated box. The compression strength test allows manufacturers to calculate a rough weight that the lowest box can handle when other boxes are stacked on top of it, so there is no risk of it crushing from being too heavy. Thus, the compression strength test refers to the measurement of the physical load a corrugated box can tolerate on top of it when it is in use.
Box compression test aids the manufacturer in understanding the maximum compression a corrugated box can handle so that it does not get deformed or collapsed. It also ensures the quality of the box material.