European database for cartonboard and carton production, 2023

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provide some degree of water resistance (hydrophobicity) and add internal and surface
strength to the product.
The dispersed fibres with the functional additives and water mixture from the
preparation plant, is pumped to the cartonboard machine and this very thin mixture (<
1% fibres in water) is put onto several continuously moving wire meshes.
As the water drains away through the wire mesh the fibres begin to 'set' and then each of
the sheets are brought together to form a continuous sheet of cartonboard.
This is then pressed between textile felts by large rollers to squeeze more water out and
then passed over steam heated cylinders to evaporate the remaining water.
When the cartonboard has reached the required moisture content, up to three layers of
coating (typically made of clay/kaolin or starch) are added to the surface of the board.
These coatings improve smoothness and gloss and are required to achieve the highquality
printing that is needed on cartons.
Modern cartonboard machines are large. Typically, they are about 100 metres in length,
about 6 metres wide and 25 metres high. They run 24 hours a day, 7 days a week and are
only stopped occasionally for essential maintenance.
Changes of the board to be made and changes of thickness or weight are carried out on
the run and the whole operation is controlled by computers to ensure consistency of
production quality. The effective production time on modern machines is in excess of
95%.
At the end of the cartonboard machine, the cartonboard is wound into huge reels which
are then moved to the finishing department. Here these reels are either cut into sheets of
the size the printer requires or into smaller reels that can be used directly on a reel fed
printing press. After cutting, the cartonboard is packed and dispatched to the carton
producers.
Modern cutting machines run continuously, have full computer control, automatic
counting and stacking of sheets onto pallets. Customer reels and pallets are wrapped in
moisture protective packaging and shipped to customers by ship, train or truck. The
mode of transportation is a balanced choice between degree of service to the customer,
cost and distance.
© RISE Research Institutes of Sweden