One of the biggest appeals of custom cardboard boxes for many businesses is that they are not only beautiful, versatile, remarkably strong, able to be cut to any size and made into practically any shape, but they are also a highly sustainable packaging material.

Outside of tin cans, cardboard is the most widely recycled material in the world, and the UK has a particularly strong track record in recycling cardboard, with the overwhelming majority of cardboard being made from recycled materials.

One question that is often asked is whether cardboard can be recycled infinitely, the same way that tin cans or glass can. Whilst many parcel boxes are either retained or reused, sometimes cardboard needs to be outright recycled into new materials.

The answer is complex and varies depending on the original quality and strength of the cardboard itself. The reasons why can be found in the recycling method, what happens when boxes are recycled, how they are turned into more boxes and why they cannot necessarily last forever.

How Are Cardboard Boxes Recycled?

The process for recycling cardboard, card and paper is relatively simple, and anything from shipping boxes and boxes of cereal to copies of the fictional autobiography Bouncing Back by Alan Partridge can be recycled in much the same way.

This process, known as pulping, involves breaking down the cardboard material into a base material that can be mixed and used to create a range of paper and cardboard products.

The Cardboard Recycling Process

• Cardboard is taken to a cardboard recycling centre and sorted by grade and type. Corrugated board is typically recycled separately from boxboard.

• Cardboard is shredded and then mixed with water and softening chemicals to turn it into a slurry-like pulp.

• Following this, the cardboard pump goes through a number of processes to get rid of ink, plastic, tape, staples and other contaminants.

• Once the pulp reaches the end of this process, the consistency is tested, and new wood pulp is added, along with additional chemicals depending on the desired end products.

How Is Cardboard Recycled To Make New Cardboard?

Once you have the clean pulp ready, it can be pressed to remove any moisture and rolled out into sheets, layered and ultimately formed into cardboard sheets.

Because of how much cardboard we use in our everyday lives, both personally and professionally, much of the cardboard we interact with has some degree of recycled material.

Is Cardboard 100 Per Cent Recycled?

It is possible for cardboard to be made from pulp made entirely of 100 per cent recycled material, although most of the time, a small amount of virgin wood pulp is added for consistency, to increase strength and to add additional properties needed to make the cardboard more useful as a product.

How Often Can Cardboard Be Recycled?

Cardboard can be very easily recycled, but unlike tin foil and tin cans, which can typically be recycled forever, there is a limit on how many times cardboard can be recycled before it becomes unusable.

Paper and cardboard are made from wood, and they retain their structural integrity through the strength of long cellulose fibres. These fibres bond together and create a new layer of paper. These can then be layered and glued to form corrugated cardboard.

When they are pulped, the fibres gradually get shorter and weaker as a natural consequence of the water and chemicals used to form the slurry, as well as the physical shredding process and the sorting processes used to remove contaminants.

At some point, the fibres get so short and weak that they can no longer be used to make paper. Usually, it takes between four and seven cycles for the cardboard to reach that level, and virgin wood pulp is often added to maximise the strength of the pulp.

If it is no longer usable for paper and cardboard, it can end up being used in other ways or can be simply added to composters to make nutrient-rich soil. 

When Can Cardboard Not Be Recycled At All?

• If it gets too wet. Cardboard often gets heavier and starts to disintegrate when exposed to high amounts of moisture.

• If it is covered in glitter, foil, velvet and some types of shiny materials.

• Old-style Pringles tubes, although newer ones are almost entirely recyclable outside of the cap and the seal.

• If it is too greasy. Many pizza boxes can be recycled, but if there is too much grease soaked in them, the boxes can become contaminated.

• If it has a plastic seal that cannot be removed.