Corrugated Board has two main components. The linerboard is the flat paper that makes up both sides of the board and the medium is the fluted paper in between the liners.
Single Wall : The medium is between two sheets of linerboard.
Double Wall : Three sheets of linerboard with two mediums in between. Great if you are stacking heavy items. It provides extra padding.
Flutes come in several standard sizes such as A, B, C, E, and F.
A Flute, the original flute, is the highest flute size, and therefore, when combined with an inner and outer facing, is the thickest. With 34 flutes to the foot, A-Flute makes the most of corrugated cushioning and stacking properties for fragile and delicate items. Because A-Flute offers excellent stiffness qualities and short column crush resistance, it has applications across a broad range of uses.
B-flute board, on the other hand, has the best flat crush resistance (50 % more than A-flute, 25 % more than C-flute) and is used primarily for die-cut boxes.
C-flute has replaced most of A-flute corrugated board since less fluting medium (approx 15 %) is required to make it.
E-flute board, which is a very thin grade, finds applications as a raw material for consumer units or display packages, often with a white, multicolour printed outer liner.
F-Flute, the newest flute, is just a little more than half the thickness of E-Flute and is the newest growth segment in the corrugated industry. The idea behind the new flute, originally developed in Europe, is to make packages with lower fibre content.
A double-wall combination made from one B-flute, single-wall sheet and one C-flute, single-wall sheet. The result is a strong corrugation used when extra thickness or stacking strength is needed.
A double-wall combination made from one B-flute, single-wall sheet and one A-flute, single-wall sheet.