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
Origin of Corrugated Paperboard
The use of corrugated paperboard apparently stemmed from clothing fashions. Pleated or ruffled collars and cuffs enjoyed a revival in the 19th century. Wringers and irons had already been developed to extract water and press clothes. Combining ideas, headed, hand-cranked corrugated rollers were adapted to press the pleats and ruffles.
In Victorian England, gentlemen wore tall, stiff hats. Cylinders of paper were used to help maintain their shape. When they got wet, the paper could be replaced. In 1856, two Englishmen, Healy and Allen, obtained a patent for the first known use of corrugated paper. Made on a hand-cranked adaptation of a collar press, it was used as the lining in hats. It was stronger than the cylinder of plain paper, and its flutes provided cushioning in the sweatband.
The first use of corrugated paper for packaging came in 1871. An American, Albert L. Jones, obtained a
patent for the use of corrugated paper for wrapping bottles and glass chimneys for kerosene lamps. It had better cushioning properties than plain paper wraps, was less messy than sawdust. Three years later, in 1874, Oliver Longto patented the concept of adding a liner to one side of the corrugated paper to prevent stretching of the flutes.
The next few years were devoted to the development of machinery to add one and then two liners to the corrugated sheet. The first mechanically-driven single facer (one liner) consisted of two machines built by George Smyth for the Thompson & Norris Co. in 1881. The first continuous corrugator, adding two liners on a single machine, was developed by Jefferson T. Ferres for the Sefton Manufacturing Co. in 1895. With two liners, corrugated board was stiff and could not be wrapped around glassware. Henry Norris and Robert Thompson teamed up to look for other packaging uses.
The concept of cutting and slotting pasteboard to make small folding cartons was already in use, so they tried similar patterns to make boxes. With the addition of slots to accommodate the thickness, they introduced "cellular board boxes" in 1894. These corrugated fiberboard boxes were much lighter and less expensive than wood boxes, and appeared suitable for the shipment of light products.
Samples of the new boxes were submitted to Wells Fargo, a major handler of small freight and light express shipments. The boxes performed well in test shipments, and were accepted as shipping containers by Wells Fargo in 1895. This marked the beginning of what is today the largest segment of America's packaging industry.
Decades of Change
Improvements in raw materials and manufacturing processes and new uses for corrugated boxes have been numerous.
The paperboard used for early corrugated containers was made from straw. About 100 years ago, the kraft process was developed to make pulp from wood. Kraft pulp is generally stronger than that made with a any other process, and corrugated box manufacturers quickly adopted the superior kraft process.
Papermaking improvements gradually extended the range of grades. Chemical additives were developed to improve wet strength or impart other properties. More, recently, higher-strength containerboard, for a given weight, has been developed thorough either mechanical or chemical procedures.
Corrugators have increased their speeds. Flying splicers permit the change of containerboard rolls without shutdown. Triplex cutoff units permit changing order dimensions with little delay. Computers improve the control and adjustment of many machine functions.
Printing has undergone dramatic change. The development of rotary presses, and of flexography using water-based inks, improved speed and reduced crush damage. Preprint and labeling techniques coincide with, and provide new opportunities in, America's changing retailing practices. Developments in adhesives, inks, waxes and other coatings have contributed to an array of new uses for corrugated. Many would not have been possible without the concurrent development of new chemicals.
The most, dynamic packaging developments came from simple adaptations. Giant corrugated boxes for furniture, appliances, and bulk products. Coatings that permit the use of corrugated for fresh fruits and vegetables, meat, poultry and fish and bag-in-box to replace glass containers for liquids are concepts that were never conceived by the pioneers of the industry.
Today, corrugated containers are the largest segment of the packaging industry.