Apr 13, 20232 min read

How And Why Is Cardboard Recycled?

Here in the UK, we use around 12.5 million tonnes of paper and cardboard each year. For context, that’s a lot of paper and cardboard!

In order to minimise the production of virgin materials and reduce our impact on the environment, it is crucial that as much of this cardboard is recycled as possible. That said, how is this done?

In the following blog post, we’ll run through the basics of the cardboard recycling process. Read on to discover more.

Sorting & Shredding

The first stage in the process of recycling cardboard involves sorting and shredding. Though it would be brilliant if all cardboard could be recycled at once, this isn't the case. Different boards are separated according to layer, corrugation and die cut features. This stage is crucial as different types of cardboard require different techniques to be properly recycled. For example, a single sheet requires far less processing than a die cut or corrugated box.

Shredding & Pulping

Once separated, the cardboard is shredded into manageable pieces before being mixed with water in purpose-built tanks. If you’ve seen soggy cardboard, you’ll have a good idea what this looks like. During this stage, the water breaks down the cardboard until it is a malleable pulp.

Filtration

Now that the waste cardboard is pulped, it is time for separation. As the cardboard that is brought to recycling plants is often contaminated, the purpose of this stage is to remove impurities such as staples, plastic and tape.

To filter the cardboard pulp, centrifugal systems are used. This simple yet effective process separates the materials based on their weight. Magnets may also be used to remove small metal items.

Rolling & Drying

Following the filtering process, the cardboard is ready to be rolled and dried. At this point, more water may be added to achieve the desired texture. By now, the mixture may be up to 90% water; vacuum rollers, conveyor belts and steam are used to treat the mixture.

Once the cardboard is appropriately rolled and dried, it bears a close resemblance to paper.

Cutting & Layering

Finally, the dried sheets of brown paper are ready to be cut and layered to form new cardboard. Typically, this involves the use of rollers to press multiple layers together. It is worth noting that different rollers can be used to achieve the desired effect.

Though the specifics of the process may vary from plant to plant, it is worth noting that the stages remain the same.