Types Of Flutes
The “Flute” describes the structure of the wave shaped cardboard material that makes up a board’s corrugation.
Flutes come in several sizes, known as flute profiles. The standard profiles range from A-flute (the largest) to F-flute and below (micro flutes).
A-flute = 36 flutes/linear foot
B-flute = 49 flutes/linear foot
C-flute = 41 flutes/linear foot
E-flute = 90 flutes/linear foot
F-flute = 128 flutes/linear foot
Generally, larger flutes provide greater strength and cushioning, while smaller flutes have better printability and fold-ability.
Flute profiles can be mixed and matched within a single piece of combined board. CE double wall is durable because of its C-flute layer, while its E-flute layer provides a smooth printing surface. A sheet of material can be made of different thickness of board to manipulate printability, compression and cushioning strengths.
A-Flute, the original flute, is the highest flute size, and therefore, when combined with an inner and outer facing, is the thickest. With 36 flutes to the foot, A-Flute makes the most of corrugated’s cushioning and stacking properties for fragile and delicate items. Because A-Flute offers excellent stiffness qualities and short column crush resistance, it has a broad range of uses.
- 36 Flutes / Foot
- 1/4″
B-Flute
B-Flute, the second flute size adopted by the corrugated industry, has lower arch heights than A and more flutes per foot (49). This means that the medium contacts and supports the liners at a greater number of points, providing a stiff, flat surface for high quality printing and die cutting and with excellent crush resistant properties. B-Flute is also preferred for high speed, automatic packing lines and for pads, dividers, partitions and other forms of inner packing. Complex die cuts and beverage trays are excellent applications for B-Flute as are can cases, wrap-around blanks, glass-to-glass packs and slipsheets. B-Flute is generally combined with lightweight liners but can be used with heavier facings if the need arises.
- 49 Flutes / Foot
- good puncture resistance
- less space consumed in warehouse
- uses: canned goods, displays
C-Flute
C-Flute came along next to split the difference between A and B Flutes. With 41 flutes per foot, it’s thinner than A-flute, thicker than B, and offers good cushioning, stacking and printing properties. C-Flute is by far the most widely used flute size. An estimated 80% of today’s corrugated containers are made of C-Flute board.
- 41 Flutes / Foot
- good stacking strength
- good crushing resistance
- very common
- uses: glass, furniture, dairy
E-Flute
E-Flute has the greatest number of flutes/foot (94) which gives it the greatest crush resistance and the flattest surface for high quality printing applications. The thin board profile of E-Flute (it is one-fourth the thickness of C-Flute) reduces box size and saves storage space. Because of its thin profile and cushioning properties, E-Flute can substitute for conventional folding cartons or solid fiber containers. Examples of E-Flute applications include boxes for cosmetics, glass, ceramic items and delicate instruments. Another growing end-use is the pizza box: a cost effective, printable container for product protection.
- 95 Flutes / Foot
- lightweight
- strong alternative to paper board
- superior printing surface
- excellent for custom die cut boxes
- uses: displays, point of purchase boxes
F-Flute
F-Flute, the newest flute, is nearly half the thickness of E-Flute and is a popular choice in the corrugated industry. The idea for F-flute originated in Europe to reduce the fibre content of packaging.
Converting to F-Flute can reduce the total amount of fibre in packaging. F-flute makes a more rigid box and sends less waste to landfills. In Europe, F-Flute is being used for specialty packaging, point-of-purchase displays, jewelry and cosmetic packages and shoe boxes. In the U.S., the McDonald’s Big Mac clamshell in F-Flute has received great attention. Dairy Queen, too, is using the F-Flute clamshell for its “Ultimate sandwich” and its hot dogs.
- 128 Flutes / Foot
- 1/32″
