There's a lot more to a corrugated box than meets the eye.

Essentially, a corrugated box is used to ship goods from one point to another or as a storage container. Whether carrying small appliances, automobile parts, or food products, the box has to be strong and durable enough for the job at hand.

Manufacturing the corrugated box begins by producing corrugated board, which gives the box its strength, durability, and adaptability. (By tearing a piece in half, you can clearly see the make-up of the corrugated board. A fluted layer is sandwiched between a bottom and top layer of linerboard.)

Here's how corrugated board is produced. Linerboard (a special type of flat cardboard sheet) is softened with steam to make it pliable. The pliable linerboard is then fed between huge metal rollers that have special meshed, gear-like teeth; to press the board into a series of permanent wavy curves (flutes). Next, a cornstarch adhesive is applied to the tips of the flutes (bottom and top) to which linerboard is glued. The result - corrugated board - is used to make the familiar corrugated box.
These flutes, which are essentially a series of connected arches, give the corrugated box its extraordinary strength. (The strength of the arch is well documented in construction and architecture. For example, the Romans were well aware of the strength of the arch and used it widely in their buildings.)
These days, corrugated box design has become a lot more sophisticated than in the past, its strength often being dictated by its use. For example, some boxes not only have to withstand the rigours of travel, but they are often stacked to great heights. If the boxes are not designed to specific strength requirements, collapsing under the load could be a real problem. For these reasons, the industry has developed numerous combinations of corrugated board types, flute sizes, weights, and strengths for virtually any shipping or storage application.
The corrugated box can be custom-designed to fit any shape (thus reducing head space between the product and the package). It is also made largely from reused/recycled material. The balance is old boxes, and sawdust and shavings from logging and wood-processing operations. In Canada, corrugated boxes have an extremely high recovery rate. For more data on recovery rates and environmental issues, click Paper and Paperboard Packaging Environmental Council (PPEC).