Corrugated board is widely used in the packing industry. The main advantages are lightness, recyclability, and low cost. This makes the material the best choice to produce containers devoted to the shipping of goods. Furthermore, examples of structure design based on corrugated boards can be found in different fields. Structural analysis of paperboard components is a crucial topic in the design of containers. many consumers are ordering their essentials online. If your business is shipping out groceries, prepared meals, and other necessities, make sure you have the right corrugated cardboard boxes and containers to transport your goods safely. You’ll find corrugated boxes used for many purposes across the food service industry, from food shipments to takeout containers.
Keep reading to learn more about the different types of corrugated cardboard and their uses.
History
In 1856 the first known corrugated material was patented for sweatband lining in top hats. During the following four decades, other forms of corrugated material were used as packaging material for glass and other products shipped in wooden crates. Then in 1894, the first corrugated printed box was made. However, by 1900 there was a nationwide network of railroads that made it possible to distribute products throughout the nation. At this point, corrugated containers were still not a recognized classification by which to ship goods. The term “contained” meant enclosed on all sides in wood. While corrugated lacked the stacking strength of wood it was more affordable, more readily available, lighter weight, more uniform in quality, and more adaptable to volume packing, sealing, and handling. It also offered cushioning and printability advantages. All of these characteristics were attractive to businessmen at that time who were eager to take advantage of nationwide distribution. The corrugated printed box was initially used for packaging glass and pottery containers. Later, the case enabled fruit and produce to be brought from the farm to the retailer without bruising, improving the return to the producers and opening up export markets.
What is Corrugated Cardboard?
Corrugated cardboard, sometimes just called corrugated, is a sturdy packaging material made of three layers of kraft paper. It’s named for the interior layer of wavy paper, also called the corrugated medium, which gives the cardboard its strength. During manufacturing, the inner sheet is put through the corrugation process to create flutes or stiff folds in the paper. The corrugated medium is then glued in between two sheets of kraft paper, which form the exterior liners. Thanks to the three-layer structure, corrugated cardboard is much stronger than regular cardboard.
What is a Corrugated Box?
Corrugated shipping boxes are made of sheets of corrugated cardboard. Stacks of corrugated cardboard are trimmed, scored, and folded to create cartons of all shapes and sizes. Glue is applied to corners and folds for even greater stability.
Benefits of Corrugated Boxes
Sandwiched between two pieces of cardboard, the ridged flutes of corrugated paper are designed to support a great deal of weight. Not only is this beneficial for shipping purposes, but it also plays an important part in supporting the weight of food in pizza boxes and corrugated cardboard takeout boxes.
This cardboard fluting construction also plays an integral role in protecting items during transportation and preventing damage. The curved arches created by these flutes make boards durable and resist pressure applied from any angle. The empty space located between the flutes and under the arches even provides cushioning, as well as insulation in the event of extreme temperature changes.
Types of Corrugated Cardboard
All corrugated cardboard has a layer of corrugated fluting and at least one liner. Fluting and liners can be combined in different layers to create different types. These are the common types of corrugated board used in packaging and shipping:
Single Face Board
Single face board has only two layers, a liner layer and a corrugated layer. It’s not as durable as the other types of corrugated cardboard but is often used inside of boxes to add extra cushioning.
- Order of Layers: Fluting, liner
- Uses: Interior packaging
Single Wall Board
Single wall board is the most common type of corrugated cardboard. If someone is talking about corrugated cardboard, they are most likely referring to this style. It consists of two outer liners and a middle layer of corrugated medium.
- Order of Layers: Liner, fluting, liner
- Uses: Shipping cartons
Double Wall Board
Double wall board has two layers of corrugated fluting and three liners, making it extremely durable.
- Order of Layers: Liner, fluting, liner, fluting, liner
- Uses: Industrial cartons
Triple Wall Board
Triple wall board sturdy enough to be used in place of wooden crates. Three layers of fluting make this corrugated cardboard a dependable choice for shipping chemicals or items that need special handling.
- Order of Layers: Liner, fluting, liner, fluting, liner, fluting, liner
- Uses: Shipping crates, chemical containers
Corrugated Flute Sizes
Different types of corrugated boxes are designated by the letters A, B, C, E, or F. The most frequently used flute corrugation is C flute, with 80% of boards and boxes making up this designation. The alphabetical designations of the flutes don’t correspond to the sizes of corrugated boxes, but rather to the order in which the flutes were invented.
Note: Measurements are approximations. Manufacturers produce corrugated flutes which may vary slightly in size.
A Flute Cardboard
Type A cardboard has excellent compression and cushioning as well as good stacking strength. It is great for packaging fragile items and is commonly used for structural strength.
- # of Flutes / Linear Foot: 36
- Flute Height: 1/4”
B Flute Cardboard
Type B cardboard has excellent crush and puncture resistance and is a great printing surface. This cardboard is commonly used for inner packaging components such as pads and partitions.
- # of Flutes / Linear Foot: 49
- Flute Height: 1/8”
C Flute Cardboard
Type C cardboard makes a good printing surface. It also has compression properties and offers crush resistance. It is most commonly used for shipping boxes and to secure glass, furniture, food, etc.
- # of Flutes / Linear Foot: 41
- Flute Height: 11/64”
E Flute Cardboard
Type E cardboard’s thin construction helps to reduce storage space. It has excellent crush resistance and an exceptional printing surface. It is commonly used for displays, pizza boxes, ballot boxes, and packaging of consumer goods such as glass, ceramics, and cosmetics.
- # of Flutes / Linear Foot: 90
- Flute Height: 1/16”
F Flute Cardboard
Type F cardboard has an outstanding printing surface and excellent crush resistance. Its thin construction allows for stiffer boxes with less fiber. It is commonly used in fast food clamshell containers and packaging for consumer goods such as cosmetics, jewelry, and shoes.
- # of Flutes / Linear Foot: 128
- Flute Height: 1/32”
| Flute designation | Flutes per foot | Flute thickness (in) | Flutes per meter | Flute thickness (mm) |
|---|---|---|---|---|
| A flute | 33 ± 3 | 3⁄16 | 108 ± 10 | 4.8 |
| B flute | 47 ± 3 | 1⁄8 | 154 ± 10 | 3.2 |
| C flute | 39 ± 3 | 5⁄32 | 128 ± 10 | 4.0 |
| E flute | 90 ± 4 | 1⁄16 | 295 ± 13 | 1.6 |
| F flute | 125 ± 4 | 1⁄32 | 420 ± 13 | 0.8 |
The inventors of corrugated board applied the same principles to paper as ancient architects did to buildings. When trying to uphold heavy loads, the most efficient way is by using an arch. Generally the larger flute profiles give greater vertical strength and cushioning. The smaller flutes help enhance graphic capabilities while providing greater structural integrity. By experimenting with flute profiles, designers can vary compression strength, cushioning strength and thickness. Flutes come in several standard sizes such as A, B, C, E, and F. Different flute profiles can be combined in one piece of combined board.
Raw Materials
The liners and medium that make up the corrugated sheet are both forms of paperboard. Paperboard is made primarily from cellulose fibers found in wood. The fibers are held together by lignin. Fibers are separated from wood in one of three ways: mechanical, chemical, & semi-chemical. Mechanical involves chipping and grinding the wood into increasingly smaller units. Chemical separation, or pulping, uses sulfite or sulfate to dissolve the lignin. This is also known as the Kraft process. This method produces the highest yields with the least damage to fibers, thus the strongest paper. The semi-chem process combines mechanical and chemical methods.
Linerboard is the paperboard used as the inner and outer facings of a corrugated sheet. It is made primarily through the chemical process. It is usually made from softwoods like Pine trees that have the longest fibers and produce the strongest board. Medium is the fluted paperboard that is in between the inner and outer facings. It is produced mainly from hardwoods that have shorter fibers through the semi-chem process.
Linerboard and medium are also made from recycled resources. Lumber byproducts like sawdust and wood chips constitute approximately 10% of the fiber supply. The recycled paper provides approximately 25%. The fibers are separated from wood or recovered through recycling processes and cleaned. The liquid paper then flows onto a moving wire screen. Water drains through the wire until it hits the dry line where a paper mat is formed. The paper is cycled through the paper machine where it is further dried, compressed, and wound into large rolls that are shipped to customers that manufacture corrugated sheets.
Corrugated Cardboard Recycling
Restaurants, grocery stores, and convenience stores accumulate corrugated cardboard with every shipment of food and supplies. Over time, the amount of cardboard quickly adds up. To dispose of the corrugated cardboard in the most efficient way, most businesses work with a local waste disposal company that collects and recycles the old corrugated containers (OCC).
To prepare the cardboard for recycling, all packing materials should be removed and the boxes must be flattened. Cardboard with grease spots cannot be recycled, so any portions of the box that have been soiled must be cut out. Tape and labels can be left in place because they are sorted out during the recycling process. For warehouses and industrial environments that produce large quantities of OCC, using a cardboard baler helps to save space.
Corrugated cardboard is the material of choice for anyone that needs to ship or package products. Now that you have an understanding of the types of corrugated boxes and fluting sizes, you can choose the corrugated cardboard that’s best for your business.
