The Ultimate Guide to Different Types of Corrugated Cardboard Sheets

Corrugated Cardboard Sheets (Corrugated Pads): 

Corrugated cardboard sheets are known for their thickness and strength, they are used as separators, for decorations, signs, arts, protection of the product in packaging boxes, making a corrugated box, and thus have versatile uses. They are best used for the protection of the product in shipping, moving, and storage. 

Below is the History of Cardboard and Corrugated Cardboard:

• 15th Century- Cardboard was used in China.
• Early 16th Century- Cardboard made its way to Europe through the Silk Road.
• 1817- Cardboard box was made in Germany to pack and sell a board game named “The Game of Besieging”. At the same time, Commercial cardboard boxes were used by M. Treverton & Son in England.
• 1871- Kellogg Company was the first food company to use cardboard boxes first to pack cereal.
• 1840- Cardboard boxes were developed in France to transport Bombyx Mori Moth and its eggs by silk manufacturers.
• 1856- Corrugated paper got a patent in England and was used for long hat liners. Edward Allen and Edward Healey did it.
• 1871- Corrugated paper was patented to be used for shipping, by Albert Jones from New York City. It was used for wrapping bottles and glass lantern chimneys.
• 1874- Oliver Long designed corrugated cardboard with Liner sheets on both sides, which was called Corrugated Cardboard.
• 1874- G. Smyth built the first machine for making double-sided- corrugated cardboard in large quantities.
• 1890- Rober Gair accidentally invented a pre-cut corrugated cardboard box. He discovered cutting and creasing of the cardboard to make a box.
• 1895- Corrugated cardboard box was first time manufactured in the USA.
• 1900- Wooden crates were replaced by corrugated cardboard cartons.
• 1908- “Corrugated Paper Board” and “Corrugated Cardboard” were used in paper trade.
• Present day- Corrugated Cardboard, Cardboard, Paper, Chipboard used in the packaging industry for various packaging items as well as used in daily usage.

Corrugated sheets are also called Corrugated Pads. Corrugated sheets are made of corrugated fiberboard, which has two smooth, flat outer kraft paper layers called liners, and in between is a wavy, fluted corrugated layer of thick kraft paper called flute. 

There are different types of corrugated sheets. Corrugated cardboard sheets are made of different types of flutes. These different types of corrugated flute sheets are used to make Single Wall Corrugated Cardboard Sheet, Double Wall Corrugated Cardboard Sheet, Triple-wall Corrugated Cardboard Sheet, and Four Wall Corrugated Cardboard Sheet.

Below are Different Types of Corrugated Cardboard Flutes:

Corrugated sheets are available in the market of different flutes. Corrugated cardboard flute is a term used to determine the thickness of the corrugated board. Flute type depends on the number of wavy corrugated flutes per linear foot. Corrugated cardboard sheets that are made of different flutes are A, B, C, E, F, D, N, G, T, and R. 

Below is the Table of Different Types Of Corrugated Cardboard Flutes, Thickness, Height, and Number of Flutes Per Linear Foot:

Flute Type	Flute Height/ Thick-ness Inches	Flute Height/ Thick-ness Milli-meter	Number of Flutes Per Linear Foot
A Flute	3/16” or 0.25 inches	4.8 mm	33-36
B Flute	1/8” or 0.125 inches	3.2mm	49
C Flute	5/32” or 0.17 inches	4mm	38-39
E Flute	1/16” or 0.06 inches	1.6mm	90
F Flute	1/32” or 0.031 inches	0.8mm	125
D Flute	5/64” or 0.22 inches	2mm	63
N Flute	1/64” or 0.02 inches	0.5mm	190-210
G Flute	1/32” or 0.031 inches	0.6mm	170-190
T Flute	1/64” or 0.046 inches	1.7mm	72
R Flute	1/6” or 0.090 inches	3mm	60

Below is the Image of Different Flute Types of Corrugated Cardboard Sheets:

For more information on different types of Flutes, Edge Crush Test and Mullen Test please visit the How to Choose the Right Flute Type in Corrugated Boxes blog

Below are Different Types of Corrugated Cardboard Sheets:

Single Face Corrugated Cardboard Sheets:

Single-face corrugated sheets have a single flat, smooth kraft paper sheet called a liner, and on top of it is a wavy, fluted corrugated layer of thick kraft paper called a flute. 

Below is the Image of the Construction of Single Face Corrugated Cardboard Sheets:

Below is the Image of Different Flute Types available in Single Face Corrugated Cardboard Sheets:

Below are the Uses of Single Face Corrugated Sheets:

• They weigh less than regular single-wall corrugated sheets and thus reduce packaging and shipping costs.
• They are best used as dividers, for wrapping the products best for metal and glass products. 
• They can be flexible or rigid, and they have higher crush resistance. 
• Single-face corrugated cohesive sheets are best for making custom pouches to wrap non-fragile products without using tape or glue.

Single Wall Corrugated Cardboard Sheets:

Single-wall corrugated sheets are made of three kraft paperboard layers. The top and bottom layers are made of flat, smooth kraft paper sheets called liners, and in the middle, there's a wavy, fluted corrugated kraft layer called flutes. As the flutes are sandwiched between the flat layers, they form a strong corrugated single-wall sheet. Single wall sheets thickness and quality depend on Basis Weight. The basis weight of any paper is measured in Pounds(lbs), Points, Cover, or GSM. In the USA paperweight is measured in Pounds. 

The most common single-wall corrugated sheets used in the market are flute B, flute C and flute E. To know more about the difference between 200 lb Single Wall Corrugated Sheets and 32 ECT please visit the 200# and 32 ECT Boxes blog

Below is the Image of Construction of Single Wall Corrugated Cardboard Sheets: 

Below is the Image of Different Flute Types available in Single Wall Corrugated Cardboard Sheets:

Below is the Table of Different Types of Single Wall Corrugated Cardboard Sheets that are used by Packaging Industry with its Weight-bearing Capacity:

MOST COMMON USED SINGLE WALL FLUTE TYPES	COMMON ECT RATING  (EDGE CRUSH TEST)	COMMON MULLEN TEST (BURST TEST)	APPROXIMATE WEIGHT CAPACITY
B, C	ECT 23	125 psi	15/20 pounds
B, C	ECT 26	150 psi	25/35 pounds
B, C	ECT 29	175 psi	45/50 pounds
B, C, A, E	ECT 32	200 psi	55/65 pounds
B, C, A	ECT 40	225 psi	75/80 pounds
B, C, A	ECT 44	300 psi	85/90 pounds
B, C, A	ECT 55	326 psi	115/120 pounds

Below are the Uses of Single Wall Corrugated Cardboard Sheets:

• Single-wall corrugated sheets are used to make shipping boxes, mailer boxes, easy-fold millers, reverse-tuck corrugated boxes, multi-depth boxes, file storage boxes, pizza boxes, corrugated bins, corrugated trays, mailing tubes (square or triangle), and corrugated displays.
• It can be used for making signs, decorative sheets, gift boxes, paintings, home decor, shelving, photo backing, or DIY projects. It can also be used for different occasions like parties, sale events, weddings, birthdays, invitations, inaugurations, school events, and award functions to make signs and posters.
• Single-wall corrugated sheets are also used as a layering pad in pallets. When used as a layering pad, it disperses weight on pallets and also keeps products dust-free during storage. It has excellent cushioning, and it also prevents damage to the products while strapping or forklifting.
• They are used as dividers to protect the products from bruising with each other in transit. Single-wall corrugated sheet dividers also protect the product in storage, moving, shipping, and transportation. And thus they are used most by the packaging industry.
• They are also perfect for moving and protecting clothing, books, office, and household items.
• They can be recycled and reused and thus create less carbon footprint behind their usage.
• They can be used to protect important documents while mailing, as they do not bend easily.
• They are best used to protect fragile items from scratching or breaking.
• The textile industry also uses it to fold shirts, sheets, and dresses for clean presentation.

Double Wall Corrugated Cardboard Sheets:

Double wall corrugated sheets are made of five kraft paperboard sheets. It has five paper sheet layers, where the first layer is a smooth flat kraft paper liner, the second layer is a wavy fluted corrugated kraft paper layer, the third layer is again smooth flat kraft paper liner, the fourth layer is again wavy fluted kraft paper corrugated layer, and the last fifth layer is again smooth flat kraft paper liner. 

Below is the Image of the Construction of Double Wall Corrugated Cardboard Sheets: 

Below are the Uses of Double Wall Corrugated Cardboard Sheets:

• Double-wall corrugated sheet products are stronger than single-wall corrugated sheets and are called Heavy-duty sheets. 
• These sheets are best used by the retail sector for storage, stacking heavy items like vegetables, fruits, furniture, small motors, small gym equipment, compressor, cans, beverages, pharmaceutical products, or any products that need protection from bending.
• They are also used to transport delicate fragile items. 
• They are also used for moving and storing purposes. 
• Double-wall corrugated sheets are also used for the protection of products from forklift damage. It is also used to make gaylord boxes, pallet boxes, furniture boxes, outer transportation boxes, postal boxes, heavy-duty boxes, file storage boxes, moving boxes, and wardrobe boxes.
• There are different types of double-wall sheets made from different flutes like EB, BB, EC, BE, AC, AB, BC, and CC. The strength of the sheets is dictated by the specific combination of the flute type chosen in their production process.
• Most common double wall sheets and boxes used are made of a combination of flute B and flute C. This combination is widely used because of its optimal strength and durable cushioning. 

Below is the Table of Different Types of Double Wall Corrugated Cardboard Sheets for the product by Weight-bearing Capacity:

POSSIBLE DOUBLE WALL FLUTE TYPES	COMMON  ECT RATING  (EDGE CRUSH TEST)	COMMON MULLEN TEST (BURST TEST)	APPROXIMATE WEIGHT CAPACITY
BC, AC	ECT 44-48	275 psi	95/100 pounds
BC, EB	ECT48	275 psi	275 pounds
BC, AC	ECT 51-55	350 psi	115/120 pounds
BC, AC	ECT 61-65	400 psi	135/140 pounds
BC, AC	ECT 71-75	500 psi	155/160 pounds
BC, AC	ECT 82	660 psi	180/185 pounds

Triple Wall Corrugated Cardboard Sheets:

Triple wall corrugated sheets are made of seven kraft paperboard sheets. It is also called Septuple Corrugated Cardboard Sheets. It has seven kraft paper sheet layers, where the first layer is smooth flat kraft paper liner, the second layer is a wavy fluted corrugated kraft paper layer, the third layer is again smooth flat kraft paper liner, the fourth layer is again wavy fluted corrugated kraft paper layer, the fifth layer is again smooth flat kraft paper liner, the sixth layer is again wavy fluted corrugated kraft layer and seventh(last) layer is smooth flat kraft paper liner. 

Below is the Image of Construction of Triple Wall Corrugated Cardboard Sheets:

Below are the Uses of Triple Wall Corrugated Cardboard Sheets:

• Triple-wall corrugated sheets are stronger and more expensive than single and double-wall corrugated sheets. 
• They have more weight-bearing capacity than double-walled corrugated sheets. 
• Triple wall corrugated sheets and boxes store and transport heavy items like furniture, appliances, heavy motors, big cans, gallons, industrial tools, compressors, pumps, gym equipment, and gaylord boxes. 
• Triple-wall corrugated sheets also provide protection for products from forklift damage. The thickness of the triple wall corrugated sheets gives extra protection, security, and stability in transportation and storage. 
• It reduces the transport cost compared to wooden boxes packaging heavy items. 
• They don't break easily so can be reused, which also reduces carbon footprint. 
• Different types of triple-wall corrugated sheets and boxes are made from different flute combinations, such as BAC, AAC, and CAC. 
• The strength of the sheets is dictated by the specific combination of the flute type chosen in their production process.

Below is the Table of Different Types of Triple Wall Corrugated Cardboard Sheets for the product by Weight-bearing Capacity:

POSSIBLE TRIPLE WALL FLUTE TYPES	COMMON  ECT RATING  (EDGE CRUSH TEST)	COMMON MULLEN TEST (BURST TEST)	APPROXIMATE WEIGHT CAPACITY
BAC, AAC	ECT 67	700 psi	230/240 pounds
BAC, AAC	ECT 80	900 psi	250/260 pounds
BAC, AAC, CAC	ECT 90	1100 psi	270/1100 pounds
BAC, AAC, CAC	ECT 112	1300 psi	290/1300 pounds

Four Wall Corrugated Cardboard Sheets or Quadruple Wall Corrugated Cardboard Sheets:

Four-wall corrugated sheets are made of nine kraft paperboard sheets. It has nine paper sheets, where the first layer is smooth flat kraft paper liner, the second layer is a wavy fluted corrugated kraft paper layer, the third layer is again smooth flat kraft paper liner, the fourth layer is again wavy fluted corrugated kraft paper layer, the fifth layer is again smooth flat kraft paper liner, the sixth layer is again wavy fluted corrugated kraft paper layer, the seventh layer is again smooth flat kraft paper liner, the eight layer is wavy fluted corrugated kraft paper layer and the last ninth layer is again smooth, flat kraft paper liner. They can also be made by gluing two double wall corrugated sheets or gluing four single wall corrugated sheets. 

Below is the Image of Construction of Four Wall Corrugated Cardboard Sheets:

Below are the Uses of Four Wall Corrugated Cardboard Sheets:

• They have extremely high weight-bearing capacity. 
• These sheets are mainly used for manufacturing Gaylord boxes. Gaylord boxes are also called bulk boxes, skid boxes, pallet boxes, octabins, or bulk bins.
• Sheets are also used to protect hefty products from skidding in shipping containers. 
• They can be made of different flute types, depending on the purpose of what they are used for, as well as the strength, cushioning, and durability required for the protection of the product. 
• They are puncture-resistant and cannot be easily crushed. 
• It can be made by using different combinations of flute types like flute A, flute B, flute C and flute E.
• They can be recycled and reused and thus have less carbon footprint. 

Five Wall Corrugated Cardboard Sheets:

Five-wall corrugated sheets can be made by gluing double wall corrugated sheets with triple wall corrugated sheets or by gluing five single wall corrugated sheets.

Below is the Image of Construction of Five Wall Corrugated Cardboard Sheets:

Below are the Uses of Five Wall Corrugated Cardboard Sheets:

• They have extremely high weight-bearing capacity. 
• These sheets are mainly used for manufacturing Gaylord boxes. Gaylord boxes are also called bulk boxes, skid boxes, pallet boxes, octabins, or bulk bins.
• Sheets are also used to protect hefty products from skidding in shipping containers. 
• They can be made of different flute types, depending on the purpose of what they are used for, as well as the strength, cushioning, and durability required for the protection of the product. 
• They are puncture-resistant and cannot be easily crushed. 
• It can be made by using different combinations of flute types like flute A, flute B, flute C and flute E.
• They can be recycled and reused and thus have less carbon footprint. 

Below is the Image of the Difference between Single Face, Single Wall, Double Wall, Triple Wall, Four Wall & Five Wall Corrugated Sheets: