Home Modules Recycling of commercial and industrial packaging The second life of cardboard

The second life of cardboard

You sort and have your cardboard waste collected. But do you also know what happens to the cardboard afterwards? Recycling gives cardboard a second life and even more. By the way, did you know that cardboard has seven lives?

With its seven lives, cardboard comes close to cats with their nine lives.

Cardboard can be recycled several times, but the quality of the fibres decreases after each round of recycling. Therefore, the limit is between 5 and 7 times, depending on the original quality of the cardboard.

Paper and cardboard waste is not always sorted separately. This process must therefore be carried out before recycling. But pretreatment involves more than that:

  1. Firstly, the material passes through a (manual or mechanical) sorting chain, where paper and cardboard are separated from each other and impurities such as plastic, metal or wood can be removed.
  2. Some paper must be shredded in a shredder.
  3. The sorted and cleaned paper and cardboard is compressed into bales and sent in bulk to the paper mills.
Le Carton

The paper mills then incorporate the paper and cardboard into the production process of new paper or cardboard:

  1. The waste is separated in drums and mixed with hot water. A screening system and centrifuges enable all the impurities (metal, plastic, etc.) to be removed. If necessary, the ink is removed from the paper by adding chemical products.
  2. After that, new fibres (lignin) are added to the paper pulp. The ratio between the recycled fibres (of lower quality) and the new wood fibres determines the strength of the cardboard or the paper. If necessary, excipients and fillers will also be added.
  3. The paper pulp obtained is placed on a sieve. At this stage, the paper pulp contains 99% water and must be compacted until only 50% water remains.
  4. The paper and cardboard are then dried in cylinders which are heated by steam and if necessary, another layer can be applied (e.g. for printing at a later stage).
  5. The paper is rolled on a spool. The cardboard is cut into sheets.

Nothing is lost, everything is reused

There are many uses for recycled cardboard and paper, but the most common remains the production of corrugated cardboard.

This cardboard packaging consists of a corrugated paper sheet that is placed between two sheets of paper or cardboard (liner). The thickness of the ‘liner cardboard’ and the corrugated paper determines the strength and the insulating properties of the packaging.