Paper / How is it made

Paper is made from the cellulose fibres contained in wood. When that fibre is used for the first time, it is called virgin fibre and when it is recovered through recycling and reused as raw material for papermaking, it is called recovered or recycled fibre. But in fact it is the same fibre at different times in its life cycle.

Cellulose

Starting from wood, first the fibres are separated (as they are bonded by a kind of glue called lignin) by "milling" the wood or dissolving the glue with heat and chemicals. It is similar to what bees do when they chew wood and make a paste with which they build their paper nests.

The paper machine

To make paper, cellulose fibres - virgin or recycled – are mixed with water in a large container called a pulper and the mixture or slurry runs through the paper machine. In the machine, the slurry of water and fibre is placed on a long band driven by rollers. Then the water is removed using several procedures: gravity, vacuum, pressure and drying. And finally an enormous sheet of paper is obtained that is then wound into a reel.

A modern papermaking line can measure 200 meters in length and occupy a surface area as big as two football fields. It has more power than 500 cars together. It has up to 5,500 km of cables, 100 km of pipelines and hundreds of valves. It is fully automatic and is handled by means of up to 50 computer screens and keyboards. Hundreds of state-of-the-art sensors and scanners handle the control processes.

Papermaking flowchart Zoom image

Recycling

Waste or used paper is collected in two ways: industrial collection (from large stores, companies, print shops, schools...) and municipal selective collection (blue bin, recycling centres, door-to-door collection from small retail outlets, offices and public buildings...).

The paper and board discarded by the citizen is placed in the blue bin, which is then emptied by a truck and taken to a paper or board recovery warehouse. The recovery company classifies it by grades, prepares it, puts it in bales and sends it to the paper mill.

This recovered waste paper enters the paper mill on belt conveyors. It is mixed with water in the pulper and agitated. The paper fibres are separated from staples, plastics...and fed into the paper machine to become new paper.

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