What happens to a bottle when you recycle it?

Every year the world produces roughly 150 million tonnes of plastic packaging, like bottles. Only 10% of that total is recycled, so there’s still a lot of potential for growth, and for recycled plastic to be used in new and different ways. Here’s the journey a plastic bottle undergoes on its way to a second life.

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If you live in a country with a formal recycling system, when you toss a bottle in the (correct!) bin, it gets collected, thrown in a truck, and sent to a sorting center, which recovers things that can be resold and discards the rest. At the sorting center, a giant crane tosses large amounts of waste onto a conveyer belt, which follows a mostly automated process, with a slight amount of human intervention, to end up sorted by commodity.

If you live in a country without a formal recycling collection system, much of this process is done by “waste-pickers,” who earn their livelihoods sifting through discarded waste and picking out the recyclables with resale value.

After being sorted, the various plastics get sent to a recycling facility, where metals are extracted (usually by magnets), thick plastics get compacted into wads by color, and plastic bottles are aggregated together.

Different destinations for recycled plastic

Most plastic bottles are made of a type of plastic called PET (Polyethylene terepthalate). PET is the easiest type of plastic to resell, because it’s easy to recycle and can be used over and over again. Every year, the world uses 100 billion tons of PET, 70% of which ends up in clothing or carpeting, and 30% of which becomes packaging material.

At recycling facilities, PET bottles are sorted by color, then immersed in a hot wash that causes labels and caps to fall away. Then, they get ground into flakes, washed, dried, heated to get rid of contaminants, and then shipped around the world for reuse. These plastic flakes eventually find their way into carpets, clothing, and other plastic products. However, because many of those products end up in landfills, groups like the Ellen MacArthur Foundation are calling for a greater focus on “circularity”, or making sure that packaging becomes a “closed loop” for materials, with the plastic from recycled bottles becoming new bottles many times over.

Bottles destined to become new bottles undergo extra steps: to meet food safety standards, the flakes are sterilized by being melted down, and then shaped into pellets from ribbons of liquid plastic. These pellets eventually get melted down again and injected into molds that will give them their ultimate shape as new bottles of other containers.

Many countries are experimenting with new ways to incentivize people to recycle. For example, in Beijing, it is possible to deposit plastic bottles into machines in subway stations and get subway tickets in return—one ticket costs 20 bottles!