Corrugated cardboard was patented in England in 1856. It is made of paper and consists of a fluted piece of paper between two flat liner boards. This construction results in a thicker, more durable product that is widely used for shipping.
This product is also called pleated paper and was originally used as a liner for hat boxes, designed to protect tall hats. A patent for its for use in shipping was issued 20 December 1871 to Albert Jones of New York City. It was commonly used for protecting bottles and glass lantern chimneys when shipping.
Oliver Long made a significant design change and added liner sheets to both sides, creating the corrugated cardboard design still in use today. A machine to manufacture this material was built in 1874 by G. Smyth. The combination of these two changes significantly increased the demand and use of this new product.
Corrugated cardboard became a very important product when Robert Gair used it to form the corrugated box in 1890. This box was able to replace wooden crates and boxes at a lower price, without losing the ability to protect the product during shipping. This box design allowed products to be shipped without damage, greatly increasing the size of the export market.
This type of cardboard is made using large corrugation machines that are able to create cardboard at a speed of 500 lineal feet per minute. To create corrugated cardboard, the paper is subjected to high pressure steam, which softens the fibers. The fibers are bent to create the required thickness of flute between the paperboard sheets.
Next, pressure is applied to the top and bottom of the cardboard to increase the strength of the material. The flat liner boards are brushed with an adhesive on one side and then the corrugated cardboard is sandwiched between the two layers of flat liner board. This material can be made in different colors, but is most commonly manufactured in brown, white or mottled white.
The thickness of the flute can be modified to create different degrees of strength in the corrugated cardboard. There are 5 standard thickness in the US, indicated by letters A through F. The letter indicates when it was invented, and not the relative size.
Within corrugated cardboard, there are different types of construction, depending on the end product requirements. Suppliers can create single wall, double wall, specific flute sizes, burst strength, edge crush strength and more. Special surface treatments, coatings and coverings can be provided as well.