There are several ways to test the strength and quality of corrugated boxes. These corrugated box testing methods range from compression strength measurements to more dynamic tests that simulate how the box will perform in real-world conditions. This post will provide a detailed look at the different types of these tests and how they are used.
Corrugated Box Testing
Corrugated boxes are used in many different industries for packaging and shipping products. In all these situations, the boxes must be strong enough to protect the contents from damage during shipping and handling.
In order to ensure that a box will be able to stand up to the rigors of the supply chain, corrugated box manufacturers subject their boxes to a variety of standard tests.
These corrugated box testing standards help to establish and maintain quality standards for the packaging industry which, in turn, helps to protect consumers and businesses alike.
Corrugated Box Testing Methods
Corrugated box testing involves several different methods. Generally, testing equipment is used to measure specific physical characteristics of the box. Corrugated box testing equipment may be as simple as a dropped weight or as complex as a computer-controlled machine. Below, we’ve outlined some of the most common corrugated box testing methods and what they measure.
Note that not all of these tests are required, and the specific tests used will vary depending on the intended use of the box.
1. Compression Strength Testing
One of the most important corrugated box testing methods is the compression strength test. This test measures the amount of force required to crush a sample box, indicating how well the box will withstand the force when stacked, either during shipping or product storage.
A sample is placed on a compression tester and force applied until the box collapses. The result of this test is then measured using a corrugated box compression strength formula called the McKee Formula.
This formula takes into account the thickness of the paperboard, the number of flutes, and the perimeter of the box. The results of this test are generally reported in pounds per square inch.
2. Bursting Strength Testing
Also called the Mullen test, the bursting strength test measures the amount of force required to rupture or break a sample corrugated box. It helps to determine how the box will perform under pressure, or the amount of weight the box can hold before breaking.
During the bursting test, corrugated box containers are subjected to the pressure exerted by a piece of rubber diaphragm. The rubber is inflated until it bursts, and the pressure at which it does so used to calculate the bursting strength.
With the Mullen test, corrugated box strength is indicated in kg per cm2 (kilograms per square centimeter). It shows how strong the corrugated material is and how it can withstand rough handling and pressure.
3 Puncture Resistance Testing
The puncture resistance test of corrugated box measures the amount of force required to puncture or make a hole in the box. This helps to determine the box’s ability to withstand sharp objects or other potential puncture threats during use.
For this test, a sample is placed on a puncture resistance tester. A weighted needle is then dropped from a specified height onto the box and the amount of force required to puncture the box is measured. The results of this test are generally reported in grams-force.
4. Cobb Sizing Tester
The Cobb sizing test is used to determine the amount of water that can be absorbed by the corrugated box and, therefore, also called the water absorption test. This test helps to establish how the box will perform when exposed to moisture or other liquids.
A sample corrugated box material (containerboard) is placed in a Cobb sizing tester and subjected to a specified amount of water pressure. The water is then drained by passing the board under a roller made of steel.
Finally, the amount of water absorbed and retained by the board is measured and the results reported as a Cobb value. Corrugated boxes with a lower Cobb value are better able to resist water absorption and moisture damage than those with a higher value.
5. Edge Crush Test (ECT)
This is one of the most important corrugated box testing methods. The edge crush test, or ECT, measures box quality and ability to endure stacking and pallet shipping.
A sample box is placed on an edge crush tester and a specified amount of force applied to the edges of the box. The amount of force required to crush the box is determined.
The results of this test are stated in pounds per inch, and represented as ECT. The ECT values provide a higher strength when compared to Mullen or Bursting tests.
This is due to the fact that the test uses a smaller area of the corrugated box board to apply pressure, making it more representative of how the box will be used in real-world applications.
6. Paper Grammage and Thickness
Corrugated grammage of the paperboard used in corrugated boxes affects the box’s overall strength and durability. Heavier boards will result in a stronger box, while lighter papers may be more susceptible to tearing or crushing.
The thickness of the paper is also an important factor to consider. Thicker papers will result in higher corrugated box strength.
However, it’s important to note that heavier and rigid boxes may be more difficult to assemble, and may not fold as easily as lighter-weight papers. Therefore, it’s important to find the right balance of paper weight and thickness for your needs.
7. Scruff Resistance Test
The scruff resistance test is used to measure a corrugated box’s ability to resist tearing. The values of the test help to ensure the box will be able to withstand rough handling that it will be subjected to during use, which ensures its durability.
For this corrugated box testing method, a metal wheel is rotated over the surface of corrugated board. The amount of force required to tear the board indicates the scruff resistance of the box.
A higher value means a stronger box that is less likely to tear during use. It also means the box is more resistant to abrasion, another type of wear and tear.
8. Chemical Resistance Test
Corrugated boxes, depending on their intended use, may need to be resistant to certain chemicals. The chemical resistance test is used to find its ability to withstand contact with chemicals without being damaged.
During this corrugated box testing procedure, a corrugated board is placed in a sealed chamber and exposed to the chemical for a specified amount of time. The board is then removed from the chamber and examined for any damage.
The results of the test will help to determine if the box is suitable for use with the chemicals it will come into contact with.
Corrugated Box Testing Benefits
A corrugated box test report provides insightful information about the performance of specific shipping or packaging boxes. This is offers several benefits to both the manufacturer and customer. The advantages of corrugated box testing standards include.
1. Determining the box’s ability to protect its contents from damage during shipping and handling.
2. Validating the corrugated box quality.
3. Demonstrating to customers and suppliers that a box meets its performance specifications.
4. Improving customer satisfaction by reducing product damage and customer complaints.
5. Reducing shipping and material costs by optimizing corrugated box design and performance.
6. Facilitating the introduction of new products to market by ensuring corrugated packaging meets all performance requirements.
7. Improving process control and quality assurance throughout the corrugated box manufacturing process.
8. Informing decisions regarding the selection of suppliers, materials, and processes used in corrugated box manufacturing.
Conclusion
Various corrugated box testing methods are used to measure the strength and durability of the box. These tests help to ensure the box will be able to withstand the rigors of use and protect the contents inside. When selecting your type of corrugated box, consider the type of test that has been performed on the box as well as the results. This will help you to choose a box that best matches your packaging and shipping needs.
