Besides the varying paper weights and types, the type (and number) of fluting must also be considered.At a basic level, a corrugated board is made up of the two liners, plus the single fluting. This is known as a “single wall”board. You can see a diagram indicating this below.However, an additional fluting section – and additional liner, can be added to make what is known as “double wall” or “double walled” material.
This effectively adds extra rigidity and strength, making it suitable for packaging heavier items and adding additional protection for items that may more delicate or expensive.You can see an example below.Finally, if the items you are shipping are particularly heavy or large (for example automotive parts, industrial equipment etc.)then a “triple walled” grade can also be used. As the name suggests, this adds another section of fluting and additional liner.
Also referred to as Tri-Wall (which is the brand name of the manufacturers too), you can see a basic diagram of this below.
Flute Explanation
The final aspect of the corrugated board that can affect its performance (and weight and cost), is the flute type.The flute is the “corrugated” section between the two liners, and by changing its’ height (and therefore the size of the flutes)it is possible to achievedifferent performance characteristics.This can vary from very fine flutes such as “E” to manufacture lightweight retail cartons (being very good to print onto), through to a more coarse flute such as an “A” or “B” flute more usually used for transit packaging.
As in the examples above, with double walled material, it is possible to combine one or more flutes to create a grade such as an “EB” or “BC” flute. This can offer a rigid structure perfect for heavier items, whilst also allowing an improved aesthetic outer
appearance and printing surface.The flute itself is usually manufactured from a waste based fluting (WBF – i.e., fully recycled material) or what is known as
semi-chem fluting (SC).
Typical paper weights used for fluting are as follows:
* 90 GSM WBF
* 105 GSM WBF – Most Common Flute Standard
* 112 SC and WBF
* 150 SC and WBF
* 175 SC and F
There are also a number of commonly used flute profiles or sizes, which are as follows:
* A FLUTE – 5mm
* B FLUTE: 3mm
* C FLUTE: 4mm
* E FLUTE: 1.5mm
* F FLUTE:.2mm
* BC FLUTE: Double Wall – 6mm -Combination of B + C flutes
* EB FLUTE: Double Wall – 4.5mm -Combination of E + B flutes
Again, this list is not exhaustive, and is complicated by the fact that many producers of corrugated material make very similarproducts which are given arbitrary names (and are exclusive to that manufacturer).
