Sustainable Corrugated Manufacturing at Industrial Scale
100% renewable, 100% recyclable corrugated sheets supporting a circular economy.
What is Corrugated?
Corrugated fiberboard or “combined board” has two main components: the liner and the medium. Both are made of a special kind of heavy paper called containerboard. Linerboard is the flat material, typically on the outer surfaces of the board but also on the inside for some structures, that adhere to the medium. Medium is the pater that is formed into arches or flutes on the single face and glued between the linerboard facings.
Flutes
Architects have known for thousands of years that an arch with the proper curve is the strongest way to span a given space. The inventors of corrugated fiberboard applied this same principle to paper when they put arches in the corrugated medium. These arches are known as flutes, and when anchored to the linerboard with an adhesive they resist bending and pressure from all directions.
When a piece of combined board is placed on its end, the arches form rigid columns, capable of supporting a great deal of weight. The flutes act to keep the linerboard sheets separated, maximizing the bending rigidity of the board. When pressure is applied to the side of the board, the space in between the flutes act as cushion to protect the container’s contents. The flutes also serve as an insulator, providing some product protection from sudden temperature changes. At the same time, the vertical linerboard provides additional strength and protects the flutes from damage.
Combined Board
The below illustration demonstrates four basic types of combined board that are most commonly created from linerboard and medium using the variety of flute structures:
- Single Face: one corrugated medium is glued to one flat sheet of linerboard.
- Single Wall: the corrugated medium is glued between two sheets of linerboard. Also known as Double Face.
- Double Wall: three sheets of linerboard with two mediums in between.
- Triple Wall: four sheets of linerboard with three mediums in between.
Generally, larger flute profiles deliver greater cushioning and vertical compression strength, while smaller flute profiles provide enhanced graphics capability. Smaller flutes such as E and F also provide enhanced structural capabilities for primary (retail) packaging compared to paperboard (folding cartons). There is a good deal of variance across the industry in the range of flute sizes based upon the container characteristics that are desired for each application.
MULLEN VS ECT
Mullen Test
The Mullen Test measures the bursting strength of corrugated board, meaning how much pressure is required to rupture the wall of the material. Boxes are rated as 200# Test, 275# Test, and higher numbers indicate stronger boxes. Mullen-rated boxes generally provide higher overall strength and better print quality, but they are heavier and more expensive than ECT alternatives.
Edge Crush Test (ECT)
The Edge Crush Test measures the stacking strength of corrugated board, or how much top-to-bottom pressure a box can withstand before crushing. Introduced in the 1990s, ECT became popular because stacking strength better reflects real-world performance during storage and shipping. Common ratings include 32ECT, 44ECT, and 48ECT.
Key Comparison
For most general-purpose applications, 200# Test and 32ECT are considered interchangeable. However, 200# Test board is slightly heavier and more costly, while 32ECT offers comparable performance at a lower cost, making it the more economical choice in many cases.
Box Strength
- 32 ECT
- 200#
- 44 ECT
- 275#
- 48 ECT
- 275# DW
Description
- Single Wall Box
- Single Wall Box
- Heavy Duty Single Wall Box
- Heavy Duty Single Wall Box
- Double Wall Box
- Double Wall Box
Box Liner Combination
- 35/23/35
- 42/23/42
- 56/23/56
- 69/23/69
- 35/23/35/23/35
- 42/23/42/23/42
Upcoming Product:
Single Face Rolls
CanCorr is developing a Single Face corrugated roll solution designed for flexible, efficient material use across packaging and industrial applications.
This product will provide single face corrugated board in roll format, enabling easy handling, cutting, and downstream processing for a wide range of uses.
Designed for
- Protective packaging and wrapping
- Industrial cushioning and separation
- Custom converting and cutting operations
- Flexible material supply for packaging lines
Built on CanCorr’s expertise in corrugated handling and production systems, the Single Face Rolls are designed with a focus on consistency, material integrity, and industrial reliability.