Pizza boxes. They’re cardboard, so they’re recyclable, right? Well, that’s only partially true, and despite what some reports would have you believe, you can recycle plenty of pizza boxes.
Takeaway pizza boxes are indeed cardboard, an almost universally recycled material. The problem with putting used ones in the recycling bin is that a greasy residue often clings to the corrugated card packaging.
This oil causes severe issues during the recycling process.
Plants reject tonnes of otherwise acceptable cardboard each year because of contamination with too much grease. Rather than being converted back into another useful resource, it often ends up being incinerated or piled onto the nearest landfill. This is a fate we are keen to avoid.
Recycled cardboard only consumes around 75% of the energy used to manufacture new cardboard from virgin pulp.
How do pizza boxes get recycled?
The mechanics behind it are quite simple. Once a batch of cardboard reaches a recycling plant or materials recovery facility, it is shredded and mixed with a solution of water, detergent, and bleaching agents to make a pulp. This can form dozens of new paper products, from newspapers and magazines to fresh cardboard boxes.
The technology exists to remove ink, staples and even sticky tape without too much of an issue.
However, oils are a much trickier problem to solve. The molecular structure of grease means it coats and clings to practically everything it encounters. This makes the strands of recoverable fibres much shorter than they would be otherwise, reducing the quality of any recycled paper so that it becomes practically useless.
It also has a detrimental effect on the equipment used during the process. As paper recycling uses cold water rather than hot, the grease is difficult to break down, and can build up to unmanageable levels.
This doesn’t mean your takeaway pizza box’s destiny is in the bin, though.