Corrugated cardboard is an incredibly versatile material that is used in the packaging developed by NOVAPOR in numerous industries - from food packaging to industrial applications. In a previous blog post we already gave a first insight into the world of corrugated cardboard Today we want to delve deeper into the subject, clarify some technical terms and explain what characterizes the different types of corrugated board and types of corrugated board. We will also explain which standards and norms ensure the quality of corrugated board and how mechanical properties such as edge impact resistance and puncture energy are measured.
Who is the VDW and what does it specify?
The VDW - A brief overview
The VDW, or Association of the Corrugated Board Industry, is a German industry association that represents the interests of corrugated board manufacturers in Germany. Since its foundation in 1948, the VDW has played a central role in the development of the corrugated board industry. Its main goal is to promote the competitiveness of the German corrugated board industry while ensuring high quality standards.
Duties and standards of the VDW
The VDW sets important standards relating to the quality and safety of corrugated cardboard. These include both technical and ecological standards. A central element of the VDW's work is the establishment of uniform quality criteria for corrugated cardboard products, which ensure that the products meet the requirements of the various areas of application.
Another important field of activity for the VDW is research and development. Through cooperation with research institutions and the promotion of innovation projects, the VDW makes a significant contribution to the further development of corrugated cardboard technology. The VDW is also committed to sustainability and promotes the use of recycled materials and the development of environmentally friendly production processes.
In addition, the VDW plays an important role in market monitoring and analysis. By collecting and evaluating market data, it supports companies in the corrugated cardboard industry in optimizing their market strategies and remaining competitive.
What types of corrugated cardboard are there?
Not all corrugated cardboard is the same. Depending on the application and requirements, there are different types of corrugated cardboard that differ in their properties and structure. The following table gives an overview of the different types. Basically, corrugated cardboard is divided into single-wall, double-wall, triple-wall and micro-corrugated cardboard.
1) For single wall corrugated board in flute type B, the values of the grade are reduced by 10 %.
The numbers on the corrugated board grades, such as "2.3", refer to the classification and marking of the corrugated board in terms of its structure and thickness. These numbers provide specific information about the number of flutes and the thickness of the corrugated board. Here is an explanation of how to understand these numbers:
Structure of numbers
- First digit (before the dot): The first digit indicates how many flutes the corrugated cardboard has.
Single-wall corrugated board
- Double-wall corrugated cardboard
- Triple-wall corrugated board
- Second digit (after the dot): The second digit indicates a number that is often related to the thickness of the corrugated board or a specific type of flute combination. These numbers are usually standardized within the industry or company.
Example: What does “2.3” mean?
2: Double-wall corrugated cardboard means that the corrugated cardboard consists of two corrugated sheets that lie between three layers of cover sheets.
3: This number can refer to a specific combination of flute types (e.g. B and C flute) or a certain thickness of the corrugated board. There is no uniform international standard that defines this number exactly, so it is often a company-specific or industry-specific number that says more about the material thickness or construction.
Exceptions prove the rule. As always, the rules do not apply to all qualities. For example, there are also triple-walled cardboard boxes, which are however designated as 2.91. This exception usually applies to quality designations from 2.91 to 2.95.
What types of flutes are there?
Corrugated cardboard is a versatile material whose properties depend largely on the type and height of the flutes used in it. These flute types determine not only the stability and damping, but also the printability and flexibility of the corrugated cardboard, which makes it particularly suitable for various packaging applications.
The following table gives you an overview of the types and the differences:
One of the oldest and most commonly used wave types is the A-flute. With a flute height of around 4.7 to 5.5 mm, it is comparatively tall, giving it excellent stackability and excellent dampening properties. These properties make A-flute ideal for transporting heavy or delicate goods that need to be well protected during transport. The greater height of A-flute also provides effective isolation from shocks and vibrations, making it a preferred choice for demanding packaging requirements.
The B-flute On the other hand, with a height of around 2.5 to 3.0 mm, it is significantly flatter than the A-flute. This flatter structure results in less stacking stability, but at the same time offers advantages in terms of printability and flexibility. The B-flute is therefore often used for packaging where high print quality and good formability of the packaging are important. It is particularly suitable for applications where it is important to design and print the packaging individually.
Between these two types of flutes lies the C-flute, which has a height of approximately 3.5 to 4.0 mm. It represents a compromise between A- and B-flute and offers a balanced combination of stackability and printability. Due to its versatility, C-flute is often used in the packaging industry and is suitable for a wide range of applications.
For smaller and lighter packaging, the E-flute is used, also known as microwave. With a wave height of around 1.0 to 1.8 mm, the E-flute is the flattest of the common wave types. Despite its low height, it offers sufficient stability and is particularly attractive when high printability and low material usage are required. These properties make the E-flute the preferred choice for smaller packaging that still needs to have an appealing look and feel.
Even flatter than the E-flute is the F-flute, which is also classified as microwave, but with a height of only about 0.6 to 1.0 mm. F-flute is often used for very small packaging, such as folding boxes, which need to be particularly aesthetically pleasing. Thanks to its extremely flat structure, F-flute offers excellent printability and a particularly high surface quality, making it ideal for high-quality, visually appealing packaging.
In summary, choosing the right type of flute in corrugated cardboard is crucial to meeting specific requirements for stability, flexibility and aesthetics. Whether for the transport of heavy goods, for pressure-intensive packaging or for small, delicate packaging solutions - each type of flute offers unique advantages that can be optimally used depending on the application.
What is edge crush resistance and how is it measured?
The Edge Crush Test (ECT) is an important indicator of the stability of corrugated boards. It indicates how much force is necessary to crush the corrugated board at its edge. This value is particularly relevant for the stackability of corrugated cardboard boxes, as the edges bear the main load when boxes are stacked on top of each other.
Measurement of edge crush resistance
The edge impact resistance is measured in a standardized test procedure. A strip of corrugated cardboard is clamped upright in a testing machine and subjected to a continuously increasing compressive force until the corrugated cardboard fails at its edge. The maximum force applied is given in Newtons per meter (N/m) and indicates the edge impact resistance.
The level of edge impact resistance depends on several factors, including the thickness and type of corrugated board and the quality of the material used. A higher edge impact resistance means that the corrugated board is better protected against external pressure and is therefore more suitable for heavier or more delicate goods.
Practical implications
In practice, edge impact resistance is particularly important for determining the stackability of cartons. A carton with a high ECT value can carry more weight without its structure collapsing. This is particularly relevant for storage and transport, where cartons must be frequently stacked on top of each other.
What is puncture resistance and how is it measured?
Puncture resistance is another important parameter that describes the resistance of corrugated cardboard. It indicates how much energy is required to pierce the corrugated cardboard with a sharp object. This value is crucial for the safety of the packaged goods, especially when the contents are pointed or have sharp edges.
Measurement of puncture resistance
Puncture resistance is measured using a special testing device equipped with a pointed probe. This probe is pressed onto the corrugated cardboard with increasing force until it penetrates the corrugated cardboard. The energy applied is measured in joules and indicates the puncture energy.
The puncture resistance of cardboards depends on its thickness, the type of corrugation and the strength of the cover layers. A higher puncture resistance means that the corrugated cardboard is more resistant to sharp objects and therefore offers better protection for the contents.
Practical implications
In practice, puncture resistance is a crucial factor, especially for packaging that is subject to mechanical stress during transport or storage. Packaging that contains pointed or sharp-edged products requires corrugated board with a high puncture resistance to ensure that the contents remain undamaged. This is of great importance for packaging for tools, glassware or electronic products, for example.
A high puncture resistance reduces the risk of external impacts or accidental dropping of a box causing damage. It therefore makes a significant contribution to transport safety, especially for shipping boxes that are subject to frequent shocks and stress.
What can finally be said about corrugated board
Corrugated board is an incredibly versatile and adaptable material that is used in numerous industries and for many different purposes. The different types of corrugated board and fluting offer solutions for almost every packaging requirement - from lightweight, printable micro-corrugated board to robust, heavy-duty triple-corrugated board for large and delicate goods. At NOVAPOR, we use corrugated board for a wide range of applications to find the perfect solutions for our customers.
Understanding technical terms such as edge impact resistance and puncture resistance is crucial for selecting the right corrugated board for specific applications. These mechanical properties determine how well the corrugated board protects against external influences and how stable it is when stacked. Knowing exactly how these properties are measured can help companies choose the optimal packaging for their needs, not only protecting the contents but also ensuring efficiency in storage and transportation.
VDW plays a central role in this by setting standards and ensuring the quality of corrugated board. By promoting innovation and sustainability, VDW is helping to ensure that corrugated board continues to play a leading role in the packaging sector in the future.
Whether shipping everyday consumer goods or transporting large industrial components, choosing the right corrugated board is critical to protecting and securing the goods being packaged. With a thorough understanding of the different grades, flute types and mechanical properties, companies can optimize their packaging solutions while reducing costs that could arise from inadequate packaging and related damage.
Our NOVAPOR sales team is happy to provide further information and detailed advice. Do not hesitate to contact us if you have any questions or need assistance in selecting the right corrugated cardboard for your specific requirements. The right choice of packaging is the key to successful transport and safe storage of your products.