How to Check Bursting Factor for Paper and Board

It is defined as the maximum pressure on the paper surface or paperboard in a perpendicular direction, required to rupture the paper. It is the strength characteristic of paper and estimates the behaviour of the packing in the process of transit like handling, loading and unloading. The bursting strength is one of the prime factors that determine the quality of the packing. There is always a quality stamp on the cartons to define the strength. This allows the carrier to remain cautious during the handling of the box. 

The corrugated board is comprised of a corrugator sandwiched between two linear boards. However, the strength of the sample does not depend on the strength of any of these. It actually depends on the raw material that is used for making these components. The resistance of paper against the rupture depends on the strength of the fibres, their length and bonding force. The quality of the pulp and additives added during the testing of the materials can play a major role in increasing the strength of the material. 

Bursting Strength Formula & How to Calculate BF of Paper

Understanding the bursting strength formula is essential in evaluating the durability and quality of paper and corrugated board. The bursting strength is the pressure required to rupture a material, usually expressed in kg/cm². To calculate the bursting factor (BF), use the formula:

Bursting Factor = (Bursting Strength in kg/cm² × 1000) / GSM of paper

This bursting factor formula helps manufacturers assess the strength-to-weight ratio of paper. If you're wondering how to calculate BF of paper, simply test the bursting strength using a digital bursting strength tester, then divide the result by the GSM and multiply by 1000.

Accurate calculation of BF ensures your paper products meet industry standards for performance and durability, especially in packaging applications.

The formula to calculate the bursting factor of the paper or cardboard is mentioned below. 

Burst factor = Bursting strength (gf/cm2) / Grammage (gf/m2)

To determine the bursting strength of the material, first, you need to have Bursting Strength Tester. This machine determines the strength of the material which is further used to determine the bursting factor and bursting index.

Presto is the leading manufacturer and supplier of Bursting Strength Testing Machine. A wide array of models is offered that suits to the testing requirements of different industries. The machine is designed as per the testing standards of different relative organisations. The machine comprises of an annular clamping mechanism to hold the specimen, a rubber diaphragm to apply the pressure. Laboratory grade glycerine is used as the medium to apply the hydraulic pressure on the specimen. The pressure is applied via rubber diaphragm. The machine work on the simple push to burst mechanism. To remove the complications, the machine is equipped with push button. The operator presses the button until the sample burst. The force required to burst the sample will be measured and displayed on the screen. 

 

For technical specifications and pricing inquiry of Bursting Strength Tester, contact our experts today. 

If you are looking for Bursting Strength Tester Price then you can consult with us. We are considered to be the leading Bursting Strength Tester Manufacturers that will provide you with high quality testing instruments to ensure zero rejections rates from your customers. To know more information about its features, price, and technical specifications, give us a call at +91 9210903903 or email us at info@prestogroup.com.

Frequently Asked Questions (FAQs)

Q) What is bursting strength in paper testing?

Ans: Bursting strength is basically the pressure a paper or corrugated sheet can handle before it finally bursts. In simple words, it tells how strong the packaging material actually is.

Test becomes important because boxes go through a lot during transportation like stacking, loading, unloading, and handling.

Q) What is BF in corrugated boxes?

Ans: BF means Bursting Factor. It is used to check the quality level of paper used in corrugated boxes. Usually, higher BF means stronger paper and better box strength.

Q) How do you calculate BF of paper?

Ans: The formula is quite simple:

Bursting Factor = (Bursting Strength × 1000) / GSM

For example, if bursting strength is 12 kg/cm² and paper GSM is 120, then the BF will be 100.

Q) Is bursting strength and BF the same thing?

Ans: No, both are different.

Bursting strength shows how much pressure the paper can bear before bursting, while BF is the value calculated from bursting strength and GSM to understand paper quality.

People in packaging industry often get confused between these two terms.

Q) Which machine is used for bursting strength test?

Ans: A Bursting Strength Tester is used for this test. The machine applies pressure on the sample until it bursts and then shows the reading on the display.

Q) Why is bursting strength important for corrugated boxes?

Ans: If the box strength is low, it can easily tear or collapse during transportation. Good bursting strength helps the box stay safe during handling and shipping.

That’s why packaging manufacturers always check box strength before dispatch.

Q) Which BF is commonly used in corrugated boxes?

Ans: Different BF grades are used according to packaging requirements.

Generally:

• 16 BF is used for lightweight boxes
• 18 BF for normal packaging
• 24 BF or higher for heavy products

The selection mostly depends on product weight and transportation conditions.

Q) What does GSM mean in paper?

Ans: GSM stands for Gram per Square Meter. It simply tells the weight of the paper.

Higher GSM does not always mean better strength, because paper quality and fibre strength also matter.

Q) Which industries use bursting strength testing?

Ans: Bursting strength testing is commonly used in:

• Corrugated box industry
• Paper industry
• Packaging companies
• FMCG sector
• Pharma packaging
• Textile packaging

Anywhere strong packaging is needed, this test becomes useful.

Q) What affects the bursting strength of paper?

Ans: There are many factors that affect bursting strength such as:

• Quality of raw material
• Fibre strength
• Moisture in paper
• Bonding between fibres
• Paper manufacturing process

Better paper quality usually gives better bursting strength results.

Q) Is bursting strength testing important for export packaging?

Ans: Yes, definitely. Export boxes travel long distances and go through rough handling, so strong packaging becomes very important to avoid product damage during shipping.