All about the board


5.3 bsm of corrugated board is made in the UK each year. An amazing statistic that shows what a huge industry we are part of. Of all the board made globally typically 60% is single wall, 30% double wall and the rest triple wall. (Source: BHS Corrugators)

A hugely versatile packaging material that is often made from paper that has at least 80% recycled content, it’s becoming ever more popular as company’s look to move away from hard to recycle packaging materials and become more sustainable.

But what is the process that our paper goes through to turn it into corrugated board?

Here’s a quick overview of the key parts of the process.

Paper types

All board grades are made using a combination of sheets of paper, referred to as liners, that are glued together with adhesive to a corrugated inner, referred to as fluting.

Two of the most common paper types, referred to in board grades are Kraft paper (chemically processed) which is typically is used for the outer liner of the board. This paper type is made from softwood and gives a smooth finish, ideal for printing. Test paper has a less smooth finish as it is made from hardwood or recycled paper which has shorter fibres. This is typically used for the inner liner or fluting.

Our five corrugators process either three or five reels of paper simultaneously to produce either single wall (two liners and one fluting) or double wall (three liners and two fluting).

The process

Firstly, reels of paper are loaded into the ‘wet end’ of the corrugator. Initially, the paper is treated with heat and steam to make it more flexible to allow for easier fluting before being fed into the single facer.  The single facer is the part of the corrugator that creates a series of arches (fluting) created by large rotating cylinders with a corrugated profile thereby creating the grooves. Different cylinders with different profiles create the different flute types.

At the next stage, adhesive is applied to the tips of the flute, and the first liner is pressed onto the fluting. A combination of steam, heat and pressure adheres the paper to the fluting to create a strong bond. This single face board, the first stage of any corrugated board production process continues its journey down the corrugated where a second liner is applied using the same methods. Less pressure is applied at this stage, so the flutes are not crushed.

To manufacture double wall board, both corrugator’s single facers will be running which delivers two single face webs to the bridge part of the corrugator to be joined together at the double glue unit. It is at this stage that the outside or double-faced liner will be joined to the single face web.

Finally, the board is cut to size both the width (deckle) and length (chop). The required sheet sizes are then palletised and ticketed for onward shipping to our sheet plant customers.

Strength and durability

Through the innovative use of different flutings, varying degrees of strength are achieved which gives corrugated its strength when used by our sheet plant customers to manufacture corrugated boxes and packaging solutions.

Different board grades are achieved by putting different paper weights and grammage through the corrugation process.

Our corrugators are all capable of making a wide range of board grades, utilising differing paper types, and fluting to meet customer requirements.

Frank Hay, Group Managing Director, Board24 commented; “The process of manufacturing corrugated board is quite fascinating, and this article has given a very simplistic view of a rather complex process.

“The introduction of our latest corrugator at Eurocentral in Scotland has seen our capacity increase significantly. It can produce more than 100 million metres squared per annum and can manufacture a wide range of flute types including B, C, M, E, BC, MB, and EB, perfectly complementing our other corrugators.”

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