Cardboard is one of the most widely recycled materials in the UK, with every local council able to collect and recycle from homes and many businesses.
With today marking the start of Recycle Week 2017 in the UK, we thought this would be a great opportunity to look at what is an incredibly important topic for the packaging industry.
The cardboard recycling process
So what happens to the cardboard that you throw into the recycling bin once your bespoke Boxtopia box has done its job?
1. The cardboard is sorted and shredded
Cardboard needs some preparation before it can be recycled. The first step is sorting the different boards, with a distinction being made between boxboard (single-layer, like a cereal box) and corrugated (the kind we use for our single wall, double wall and die-cut boxes - two or more sheets sandwiching a creased layer).
Sorting is important because not all cardboard is created equally. Different types are made from different materials and processes, and those different types are only suitable to be recycled into certain products. Once it’s been sorted, the cardboard can be shredded into smaller pieces that work better in the later stages of the process.
2. It is mixed with water and pulped
The shredded material is poured into big tanks and mixed with water. This process, known as pulping, softens the cardboard and starts to make it into something that can be used as a material for new products.
3. The pulp is filtered
Waste cardboard is rarely 100% board. It nearly always gets mixed up with foreign materials like tape, staples and plastic packaging. A centrifugal systems are used to separate the various materials, based on weight. Magnets also help to remove metal items, however small.
Only after filtering is the pulp suitable to be stored for such a time as it is needed to make new cardboard in the future.
4. More water is added
When it’s required for manufacturing, the pulp is mixed with water again, pressed and stirred. This process helps get it to the right consistency for use further down the line. The length of this stage will depend on the kind of cardboard being manufactured and the materials being used. At this point, chemicals can be added to give the mix additional characteristics, like water-resistance.
5. The mixture is rolled and dried
At the start of this stage, the mixture can contain up to 90% water, so it has to be treated before it can turn into anything more useful. A range of techniques can help at this stage, including vacuum rollers, vibrating conveyor belts and steam heating.
Ultimately, pressing the sheet through rollers helps to turn the sheet into something starting to resemble paper. The rollers are also used to add additional layers to the cardboard, depending on how thick it needs to be.
6. Sheets are converted to new cardboard
The result of the process is huge reels of brown paper, weighing several tonnes. These can then be cut to size and layered to make thicker cardboard.
In the case of corrugated cardboard, the sheets for the central sections are taken through rolls with teeth rather than smooth surfaces, which gives them that crinkled, ridged shape, that will go on to provide additional strength to the kind of board that we use for our boxes.
The recycling processes can vary depending on the recycling plant and the paper factory, but the basic steps remain the same: sorting, shredding, pulping, filtering, drying, pressing and rolling.
Environmental benefits of cardboard recycling
Recycling cardboard is better for the environment in every way than making cardboard from new materials (‘virgin’ trees). Estimates vary on how much energy is saved by manufacturing cardboard from recycled materials, but the general consensus is somewhere between 25% and 50% saved. In addition, recycled cardboard means using between 70% and 100% less virgin material, and even up to 99% less water.
When manufactured in the UK, making cardboard from recycled material also saves on emissions from importing materials from overseas. The UK’s landmass is only about 12% forest and we can’t produce enough wood sustainably to manufacture the amount of paper and cardboard that we do. Recycling circumvents this problem, with the materials already being in the country.
We hope that gaining a little insight into how cardboard is recycled stops it being a mysterious, magical process and turns it into something that has a clear goal and benefit, both to the environment and to British industry. If your business doesn’t already recycle its cardboard, it’s never too late to start!