Edge crush resistance, burst strength and puncture resistance

High-quality packaging is essential for safe storage and undamaged transport of sensitive goods. They must therefore be sufficiently strong and robust to withstand the stresses to which they are subjected during handling. For this purpose, they are subjected to standardized physical-technical test procedures, in the course of which important quality properties are determined.

Importance of the safe transport of goods: damage-free handling of the goods

When designing packaging materials, the focus is on how the goods can be optimally protected. Especially in the mail order business, it is important that corrugated board and other materials withstand various loads. For companies as well as for business or private customers, well thought-out and secure packaging is important so that the goods arrive without damage.

Today, cardboard packaging ideally fulfills several requirements at once. On the one hand, you have an interest in packaging that is as convenient and manageable as possible. On the other hand, your packaging material must be able to withstand a lot of stress and heavy weight as well as improper handling. Especially when several units are stacked on top of each other during the transport of packaging, the lower rows are exposed to a great deal of stress.

To guarantee these properties, cardboard packaging must withstand certain standardized technical test procedures. As part of these, defined properties and parameters are determined that allow conclusions to be drawn about the load-bearing capacity and quality of the materials. These properties to be tested include:

• the edge crush resistance
• the puncture resistance
• the burst strength
• the total weight per unit area
• the weight per unit area of the individual layer
• the thickness measurement of the corrugated board

Numerous physical-technical test methods are available for determining these and other parameters. In combination with certain material standards according to DIN EN ISO, these help to ensure safe handling and damage-free transport.

What is the edge crush resistance?

Edge crush resistance is a central value in determining the stability of a package. Edge crush resistance plays a particularly important role in stacking.

It thus determines the maximum possible amount of force acting perpendicular to the shafts. It is typically specified in the unit kilonewtons per meter. As one of the most important benchmarks in packaging development, edge crush resistance places high demands on the accuracy of the specimen.

The edge crush resistance provides an indication of how strong the side walls of a cardboard box are when a weight is applied to your packaging from above.

How can edge crush resistance be determined and why is it important?

The edge crush resistance is determined within the framework of the so-called edge crush test. There is a standard according to which this measurand is defined: DIN EN ISO 3037. For the determination, a test press is used that exerts targeted pressure on a test piece standing vertically (on edge).

This is done until the piece yields under the load. The flutes of the cardboard are perpendicular to the plate of the press. This makes this method different from the determination of flat crush resistance, in which the device applies pressure to the tips of the flutes.

The Edge Crush Test requires an exact cut of the specimen. This consists of a strip measuring 100 mm (tolerance limit: 0.5 mm). The test piece must be cut out exactly vertically in the direction of the glue lines and must have a height of 25 mm.

Furthermore, similar to other test methods, precise laboratory criteria are prescribed for this test. The test must be carried out at 23 degrees Celsius and the humidity should be 50 percent. Furthermore, the cardboard should be free of processing marks and clean during the test.

Typically, ten identical samples are tested. An average value is formed from the results. The values are not related to the area, as in other test methods, but to the length of the perpendicular edges.

The edge crush resistance thus provides an indication of the storage and transportability of packaging material. The higher the measured value, the greater the suitability of the cardboard boxes for stacking without damage.

As a measured value, the edge crush resistance is also important for determining the pile crush resistance. This stands for the maximum force that a finished carton can bear without buckling. It should be noted that the load-bearing capacity of materials in practice also depends on factors such as air humidity and temperatures.

Puncture resistance: what is it and why does it matter?

Puncture resistance is another measure of the strength and rigidity of packaging materials, especially paper and cardboard packaging.

The test is subject to the specifications of DIN 53142 and is performed using a device in which a pyramid-shaped body is pressed onto the specimen. A higher puncture resistance means that the material is more resistant to mechanical loads and is therefore better suited to protecting and transporting goods.

There are various test methods to determine the puncture resistance of packaging materials.

The results of these tests are expressed in units such as newtons (N), joules (J) or kilopascals (kPa) and can be used to select and evaluate packaging materials.

One of the test methods is the so-called "puncturability test", in which a steel ball is shot at the packaging with a certain mass and speed and the puncture resistance is measured.

Another method is the "penetration test", in which a pointed instrument penetrates the packaging with a defined force and the puncture resistance is measured. There are also methods in which the material of the packaging is put under pressure on a test rig to determine the puncture resistance.

The exact way in which these tests are carried out depends on the specific packaging and the requirements placed on it.

Puncture resistance is often used as an important quality criterion for packaging materials, as it is an indicator of the safety and reliability of the packaging. It is particularly important when it comes to packaging sensitive goods such as food, medicines or electronic devices, as these require special protection.

The puncture resistance indicates how much force is required to pierce the material. Unlike the edge crush resistance test, a point load is applied here.

Bursting strength: definition and relevance

Burst strength is defined for cartons or cardboard in the DIN 53 141-1 standard. It is an important property of cardboard packaging that indicates how much pressure or force the material can withstand before it breaks or is damaged. It is often used as a measure of the strength and reliability of cardboard packaging and is particularly important when it comes to packaging and transporting goods.

The bursting strength of cardboard packaging can be measured in different directions, depending on the direction in which the material is loaded. For example, there is the bursting strength in the longitudinal direction (Longitudinal Bursting Strength), the bursting strength in the transverse direction (Transverse Bursting Strength) and the bursting strength in the layer direction (Layer Bursting Strength).

There are various test methods to determine the bursting strength of cardboard boxes, such as the "Bursting Test" or the "Mullen Burst Test". The results of these tests are expressed in units such as kilopascals (kPa) or pounds per square inch (psi) and can be used for the selection and evaluation of cardboard boxes.

Bursting strength is of great relevance to the aspects of load-bearing capacity and transportability of packaging materials. The load-bearing capacity of packaging is an important factor to consider when selecting packaging materials. It indicates how much weight a package can carry without being damaged.

Packaging with a high load capacity is capable of safely transporting heavy goods without damaging them. It is important that the load capacity of the packaging corresponds to the weight of the goods to be packed to ensure safe transport.

The bursting strength of packaging is particularly important when transporting goods. During the transport process, packaging is frequently subjected to mechanical stresses, such as impacts, vibrations or pressure.

Packaging with a high burst strength is able to withstand these loads and thus minimize the risk of damage to the packaged goods. It is therefore advisable to use packaging materials with a high burst strength to ensure safe and reliable transportation of goods

 

Conclusion

Important quality properties of packaging materials include edge crush resistance, burst strength and puncture resistance. These are determined and optimized in respective standardized procedures according to technical-physical methods.

Quality features never stand alone, but only allow clear statements on packaging quality in interaction with each other. As a German packaging company with a focus on sustainably produced materials, we offer you a wide range of safe and tested packaging for optimal transport.

FAQ

1. What is the significance of edge crush resistance, burst strength and puncture resistance in practice?

   Edge crush resistance, burst strength and puncture resistance are important properties of packaging materials that affect the strength and reliability of packaging.

   They indicate how much force or pressure the material can withstand before it is damaged and are therefore important for minimizing the risk of damage to the packaged goods during the transport process. They are often used as quality criteria to simplify and evaluate the choice of packaging materials.

2. How can packaging be sustainable and safe at the same time?

   It is possible to make packaging both sustainable and safe. There are various ways to achieve this: using renewable raw materials, using recycled materials, avoiding over-packaging and using reusable packaging.

   In all these packages, a safe design is possible to avoid damage to the goods during the transport process. There are various properties that influence the safety of packaging, such as bursting strength, puncture resistance or edge crush resistance.

   Targeted packaging design that takes these characteristics into account can produce safe packaging that is also sustainable.

Do you have any questions about this topic? Feel free to contact our expertswho will be happy to support you or write to us via hello@palamo.com.