Basic information - How is corrugated board constructed?

The invention of corrugated board dates back to the 19th century. The first patent was registered by the Englishmen Edward Charles Healey and Edward Ellis Allen in 1856 - for corrugated paper used to line hats.

From then on, the use of cardboard as a packaging material was steadily developed by several British and US. The product itself has changed over time as follows: The corrugated paper was first glued to a smooth paper web on one side, and later on both sides.

In 1882, Robert H. Tompson received the patent for what we know today as single wall corrugated board. Also at this time, the first machines were manufactured to produce this type of cardboard on an industrial scale.

Basic structure

Corrugated board consists of two top layers, i.e. an inner and an outer layer. These two layers are connected by a corrugated middle layer. This middle layer is also called a corrugated sheet. In the case of corrugated board produced in Germany, the latter has the shape of a sine curve, i.e. it is very uniform.

The quality of the corrugated web, in turn, is decisive for how thick or thin the board is at the end, or which flute is used. Two values are relevant here: The wave height (h) and the wave pitch (t).

The former is the measurement between the wave trough and the wave peak, or between the top and bottom points of a wave curve. The latter indicates the distance between two wave peaks.

Shaft types and material used

In addition, there are several types of corrugated board. In addition to the simple flute , it is also possible to glue several layers of corrugated board on top of each other. This creates double flutes or even a triple flute corrugated board - double flute board is alternatively called double wall board.

 

A well-known and common example of a double corrugation is the so-called EB-flute. The more corrugations are layered on top of each other, the more stable and load-bearing the material is.

In the vast majority of cases, the corrugated web is made of recycled materials, which has a great advantage for the issue of sustainability.

The ceiling webs can be made of testliner or kraftliner paper. Another option is the production from the so-called Schrenz. This is unsorted waste paper that is recycled.

The options each have advantages and disadvantages. While testliner paper is made from recycled material, kraftliner is made predominantly from primary fibers, i.e. non-recycled material.

Therefore, the latter is less sustainable. However, the most stable corrugated board can be produced with the use of kraft liner paper, so manufacturers and buyers must make a sensible individual trade-off.

Manufacturing process

You may be wondering how the corrugated shape of the inner web is created. Basically, corrugated board is manufactured in a corrugator (corrugator). Here, the paper that runs off a web is first moistened and heated to make it malleable. It then runs through two corrugating rolls.

These are also known as corrugating rolls. The paper is corrugated under high pressure. This process can be used to emboss a wide variety of corrugated shapes.

The finished corrugated web is then glued on both sides with smooth paper webs - this produces single wall corrugated board. For multiwall corrugated board, further fluted and smooth paper webs are added.

Finally, the corrugated board is processed in converting machines into the desired packaging, which in turn can be printed and finished using various techniques.

What is the E-flute?

As already mentioned, there are many different types of waves. These include, among others:

• the E-flute,

• the B-flute and

• the EB-flute.

One of the flatter variants is the so-called E-flute. Like the F-flute, it is classified in the category of micro- and microwaves. The rather delicate and thin character of this flute becomes particularly clear when looking at its dimensions.

The dimensions of the flute, wave height and the wave pitch, are fixed to a certain extent for all types of waves, so they still leave some room for maneuver in the design.

With regard to the shaft pitch (t) of the E-flute, this frame is between 2.6 and 3.5 mm. The dimensions of the shaft height (h) of the E-flute are between 1.0 mm and 1.9 mm. Packages made of E-flute can be loaded with a maximum weight of 7 kg.

 

What is the B-flute?

The B-flute belongs to the fine shaft category, so it is already classified differently from the E-flute when looking at the higher-level types. The dimensions of the shaft height are between 2.2 and 3.1 mm and the dimensions for the shaft pitch are in a range between 4.8 and 6.5 mm. Due to the larger shaft path, the B-flute can be loaded with more weight than the E-flute - up to 14 kg is possible.

The B-flute has significantly larger dimensions in terms of wave pitch and wave height than the E-flute.

What is the EB-flute?

The EB-flute , in turn, belongs to the double shaft category. As a combination of E- and B-flute, it consists not only of one flute with ceiling tracks, but of two.

The dimensions of the EB-flute result from the addition of the two shafts glued on top of each other. However, this leads to other special features.

The scope that the flute pitch and the flute height can have in terms of their dimensions with an EB-flute is, as a logical consequence, much greater than with a simple fine flute or fine flute. In addition, packaging with EB-flute is particularly stable and can therefore also support a much higher weight than single-flute corrugated board, namely up to 32 kg.

By the way: The EB-flute is not the only double shaft the market has to offer. Rather, there are various combinations that shine with individual properties and advantages. Among other things, the common double shafts also include the BC-flute.

 

Advantages of the respective variants

Perhaps, when looking at the individual types of corrugations, you have already asked yourself why the different structures of corrugated board are necessary at all. This is due to the fact that each of the types of corrugation shines with individual advantages that make them unique.

Basic advantages of corrugated board

First, however, it is worthwhile to be aware of the basic advantages of corrugated board. These include, first and foremost, a certain efficiency: the interstices created in the cardboard due to the corrugation make the material particularly stable.

This is because the corrugated web absorbs pressure and shocks and distributes their acting force to the outer layers of the blanket. This makes the corrugated board very robust overall and ideal for cushioning and protecting the packaged goods.

At the same time, this construction method means that the cardboard is very light compared to other packaging materials. In this combination, this makes corrugated board a unique product in the packaging sector.

Sustainable packaging material

In addition, corrugated board is extremely sustainable. It consists entirely of renewable raw materials: For the most part, it is made from recycled materials. The rest is contributed from broken and thinned wood from sustainably managed forests.

In addition, corrugated board is often recyclable again. The adhesive used for processing into packaging is natural glue based on vegetable starch. Environmentally friendly inks can be used for printing. Alternatively, the cartons remain unprinted and they are provided with a label - again sustainable.

Individual preferences of the types of waves

The e-flute shines above all because it looks delicate and is particularly easy to print. This opens up a wide range of options for you as a user for a high-quality look of the packaging, which helps to achieve an extensive marketing effect.

The better the result of the print, the greater the attention of potential customers. In addition, the thin flute has the advantage of saving a lot of storage space, especially for a large number of packages.

The B-flute, on the other hand, shines due to its higher dimensions in terms of corrugation pitch and corrugation height due to its particular stability. As a result, packaging made of such a material can be loaded with a higher weight and accordingly used more flexibly.

However, due to the higher flutes, the surface of the corrugated board is not quite as smooth and even as with the E-flute. This makes the B-flute somewhat less printable, although very good printing results are still achieved.

The EB-flute combines the advantages of both variants. On the one hand, it is particularly stable and load-bearing. This property is further enhanced by the double flute design. At the same time, the cardboard on the side of the E-flute is very easy to print. In addition to its stability, this creates packaging that is ideally suited as a marketing tool.

 

Areas of application of the three types of shafts

As you can imagine, the individual advantages mean that the individual shaft types are also used for different applications.

The E-flute is often used as a material for primary packaging, but is also suitable for shipping light products weighing up to 7 kg. These can be, for example, food, IT goods and electronic items.

Due to the property of being easily printable, it can be used especially for high quality products. The packaging reflects the quality of the content.

The B-flute is also convincing as primary packaging at the point of sale and as secondary packaging during shipping. In general, it is the ideal protection for products weighing up to 14 kg - for example, books, textiles, electronic items and smaller household appliances. The B-flute is thus more load-bearing than the E-flute, but not as resilient as a double corrugated.

Packaging made of cardboard with an EB-flute is used primarily as shipping packaging due to its stability. For online stores, for example, they offer the possibility of shipping even heavier goods of up to 32 kg to customers. Examples of products are medium-weight electronic items or larger construction or spare parts.

At the same time, the flute offers a certain level of security due to its stability, which means that the goods arrive undamaged. And cardboard packaging with EB-flute meets another important criterion: They can be printed withhigh quality on the side of the E-flute . This helps to create a great unboxing experience and, as a consequence, to establish a certain customer loyalty.

Contact us if you have any questions about our products and the different types of corrugated board. We will be happy to help you!

Conclusion

Corrugated packaging has a whole range of advantages. These include, among other things, high stability combined with light weight, which brings a certain efficiency. In addition, the individual flutes offer quite individual advantages.

The E-flute , for example, is particularly suitable for printing, while the B-flute is somewhat more stable. Finally, the EB-flute double flute combines the positive properties of both flute types.

 

FAQ

1. What is the difference between the types of waves?

   The individual wave types differ mainly in the dimensions of the wave height and the wave pitch. Accordingly, they offer individual advantages that can be used by you as an entrepreneur.

2. What are the special features of the EB-flute?

   The EB-flute is a double flute, i.e. it consists of two corrugated board parts glued on top of each other. It is characterized above all by its high stability and by the fact that it combines the advantages of the E-flute and B-flute .