Corrugated cardboard is most often recognised by the fluted or wavy section of paper that is glued between two flat, smooth pieces of cardboard. The layered construction of corrugated cardboard produces a much thicker and more durable cardboard material that is popular for use in shipping and transport. Although most corrugated cardboard may look similar to the untrained eye, there are actually several different types of corrugated cardboard to meet various shipping, storage and packaging needs.
Corrugated cardboard is made of two components called the linerboard and the medium. Both sections are made of a heavy-duty paper material. The linerboard is the flat cardboard facing that adheres to the medium, and the medium is the wavy or fluted paper that is glued between the liner boards. The type of corrugated cardboard known as single face consists of just one layer of linerboard with the fluted medium adhered on top. The two-layered construction features one smooth side and one ridged side, which offers padded protection as well as some limited flexibility to the cardboard piece.
The single wall construction of corrugated cardboard is also sometimes referred to as a double face because it creates a mirror image of the single face corrugated construction. The single wall material is made with a single section of the wavy medium sandwiched between two sheets of flat linerboard. Although the end result is considered a single layer of corrugated cardboard, it is actually constructed out of three individual layers.
A double wall corrugated cardboard is made with two layers of fluted medium in the middle. Each fluted layer is separated by a sheet of linerboard in the centre. The finished product is made with three sheets of flat linerboard alternating with two sections of fluted medium. Double wall and even triple wall corrugated cardboard is often used to ship and store heavy parts that might rip through traditional types of cardboard. Double wall corrugated cardboard also provides superior protection to items packed inside.
Architecture demonstrates how a properly curved arch can provide exceptional support and stability. Corrugated cardboard uses this principle in the construction of the fluted layer, which can support a great deal of weight and resists collapse. Corrugated cardboard may be made with different styles of flutes that vary in thickness and shape. Wider spaced, curving flutes provide general support but remain lightweight. More tightly spaced triangular flutes create a heavier, more dense cardboard that is useful for stacking and heavy-duty shipping.