Corrugated cardboard is a composite material (paper and glue) constructed in such a manner as to increase the mechanical strength of the paper.
In all corrugated products there is at least one layer of corrugated paper - the medium; and at it's simplest one layer of paper - the liner.
Corrugated cardboard products are constructed in various forms and are classified as such:
A. Single Face Board
Consists of one layer of corrugated material called the medium and one flat layer glued to and holding the medium in place and shape.
B. Single Wall Corrugated
By adding another liner to the single face a rigid material is created with an inside liner usually made of totally recycled paper and an outside liner (varying in recycle from 0-100%). This has a better finish, which allows the paper to stretch when folded and provide a good substrate for printing. This board is used for most standard cartons.
C. Double Walled Corrugated
When a second layer of single face (usually of different flute) is added to the single wall board, then twin cushion or double wall corrugated cardboard is created. This material is for heavy duty cartons.
D. Triple Wall Corrugated
By adding a 3rd layer of single face Triple Wall (or tri wall) is created. This material is very specialised and used for a limited number of shipping cartons. It's price is usually too prohibitive, to be a practical carton material.
E. Duo Arch
By doubling the corrugating medium on a single wall carton, Duo Arch is created. This gives the board a very rigid quality. It may be added into twin cushion board for extra strength. Duo Arch with single or double wall is usually associated with very heavy cartons.
In corrugated board, thickness of the material determines rigidity and stiffness. This is achieved by separating the outside layers with a corrugated medium to reduce weight and cost.
Fluting medium is actually a paper and its role in flat crush, edge compression and bulge resistance are all important factors when determining the performance of the board.
Performance is dependent on the type of flute and the fluting material.
For the most part the medium is made of one type of paper, usually in the region of 112gsm to 120gsm, but it can be bolstered by using a higher medium or creating a duo-arch.
There are 4 regular flutes that Kebet uses in the manufacture of corrugated cartons i.e. A, B, C, & E Flutes.
Flutes per Metre
|A||5.3 + 0.5 mm||110 to 120|
|B||2.8 + 0.5 mm||155 to 175|
|C||3.5 + 0.5 mm||130 to 140|
|E||2.0 + 0.5 mm||295 to 325|
Twin Cushion Flutes
Other flutes (not handled by Kebet)
5b / 5c
4b / 4c
3c / 3b
1c / 1b
1c / 1a Super