A corrugator is a set of machines in line, designed to bring together three, five or seven sheets of paper to form single, double or triple wall board. This operation is achieved in a continuous process. The reels of paper are fed into the corrugator, the paper is conditioned with heat and steam and fed between large corrugating rolls which give the paper its fluted shape in the Single Facer. Starch is applied to the tips of the flutes on one side and the inner liner is glued to the fluting. The corrugated fluting medium with one liner attached to it is called single face web and travels along the machine towards Double Backer where the single face web meets the outer liner and forms corrugated board. The corrugated board is then cut and stacked.
These are the machines which feed the paper rolls into the corrugator and enable rolls to be changed without interrupting the production of corrugated board.
The single facer:
This machine transforms the paper into a series of connected arches called « flutes » thanks to the corrugating rolls that are large cylinders with a corrugated profile. If the flute profile has to be changed, then the corrugating rolls need to be changed.
The double backer:
It glues the outer liner to the fluting to obtain single, double or triple wallboard. The single face web is pre heated, starch is applied to the tips of the flutes. The outer liner is then bonded to the single face web to form corrugated board. It is a complex operation that requires great expertise in the pre-heating, moisture control and gluing processes.
This enables the Double Backer to run at different speeds from the Single Facer especially when reel or order changes take place. This is achieved by the single face web forming festoons that are controlled at the Single Facer station.
Corrugated boxes are everywhere. This simple yet profound packaging medium is now ubiquitous, having emerged as the largest transport packaging material. Millions of tones of agricultural and industrial production are transported from the factory to markets in this cost-effective yet sturdy packaging medium.
In the late nineteenth century (1871), Albert Jones discovered an ingenious way of giving strength to paper. He took a piece of paper, convoluted it into a series of flutings, by moistening it and passing it between two hot corrugated rolls. What he ended up with it is shown below:
In 1874, a fellow American named Oliver Long discovered that when a flat sheet of paper was glued to one side of the corrugated paper, It kept its shape even when it was stretched and subjected to pressure. This gave rise to what is today known as a single face corrugated and it was also the birth of the corrugated board industry.
In 1962, Inland pioneered the use of 100% soft grade kraftliner, which provided greater tear and puncture strength.