What is Corrugated Board?

Corrugated packaging is made from corrugated board, a combination of containerboard materials structured to provide maximum strength properties.

Single wall corrugated board consists of three containerboard components; outer liner, inner liner and fluting medium.

The Outer Liner:

Often high quality and printed with company branding or advice.

The Inner Liner:

Less important from an aesthetic perspective but very important for strength. This part of the package has direct contact with foodstuffs and other products and as such may have to conform to special requirements.
The term is most often used to describe the containerboard materials;

• Kraft: Originally containerboard made from 100% wood pulp, Kraft mills are increasingly using recycled waste as a proportion of the fibre content. Kraft comes in a number of forms including; Untreated (Brown), Bleached (White), White Top Kraft and Mottled Kraft.

• Test: Modern Test Liners are made entirely from recycled fibres. Selected waste papers are combined to produce different grades of 2-ply or multi-ply liners such as; Brown Tests, White Top Tests, TL3 Grade and TL2 Grade.

The Fluting Medium:

Specifically formulated paper that can be readily corrugated (crinkled) when heat and pressure are applied, but ridged when cool. The fluting separates the liners and gives corrugated its strong rigid properties.

Fluting Medium is manufactured by two processes, the first uses recycled paper with added chemicals and starch to produce a strong sheet ‘flutability’. The second process uses both mechanical and chemical means to reduce wood to its component fibres. Other variations of corrugated board can include Quadflute which is used for heavy duty applications.