Bursting Strength Claculation

How to Calculate the Bursting Strength of Corrugated Boxes?

Quality is never about the high strength of the material, it is about having the appropriate strength. In certain applications, you require material to have high strength whereas in some applications you need to have the low strength for right tearing. Different customers have different requirements regarding the strength of the corrugated boxes. And, a manufacturer has to fulfil those demands to retain the client. Thus, measuring the bursting strength is an important factor of corrugated fibre boards. 

Measurement of bursting strength

When we are talking about the quality of the packaging, we are also talking about the quality of the raw materials used. So, to understand the quality of the box, we must understand the quality of the fibre board first. It is certainly impossible to measure the bursting strength manually, you need to have a smart bursting strength tester to do the job. Having a machine would ensure that measurements taken by you are standardized. Three values we need to consider;

  • Bursting Strength
  • Bursting factor
  • Bursting Index

Bursting Strength of materials tells about the property of the material to bear the stress when an external pressure is applied to it. Following are steps involved in measuring the strength. 

Prepare a circular sample of dimensions larger than the annular clamp. The dimensions of the sample are very important so that it does not slip during the testing.

  • Clamp the sample appropriate on the annular clamp
  • Using the ‘push to burst’ switch to apply the hydraulic pressure on the sample.
  • The pressure is applied via a rubber diaphragm which inflates when hydraulic pressure is increased. 
  • The point at which sample burst, the machine notes down the pressure applied. 

Using this bursting strength, bursting factor and bursting index can be determined. 

Burst factor = Bursting strength (gf/cm2) / Grammage (gf/m2) 
Burst Index = Bursting strength (kPa) / Grammage (gf/m2)
kPa = kilopascal,
Kgf = kilogram force
Gf = Gram Force
Grammage = Base weight in units of gf/m2


Why is BS tester used in Packaging Industry?

The testing machine is used in packaging industries to measure the effects of peripheral forces and which is exerted on the containers when an excessive amount of a product is packed inside. The testing apparatus is used by the manufacturers to produce lightweight and decompression boxes to provide high-quality packaging material to the customers. To ensure the quality of the packaging products, the manufacturers of packaging products buy high-quality of the testing machine from the reputed manufacturers of testing machines that are designed using sophisticated technology and high-quality material.