Heavy duty boxes are manufactured using a heavier linerboard. Mostly used for industrial, agricultural, and other commercial applications these corrugated boxes are often double stacked in the back of the trailer. Air cargo containers are boxes that are deemed heavy duty along with gaylord containers. Many food manufacturers require food grade packaging, FDA approved boxes lined with poly bags which tend to be in the heavier class. These boxes are used as bulk bins and in some cases can be used more than once. Most heavy duty boxes fit in the category of large corrugated boxes. When flattened these boxes commonly occupy a footprint of 90” X 88”. This makes them very cumbersome and bulky to transport with a freight company because they are very high density and take up a large amount of space.