How many plastic cups do you need to recycle to generate one 3D printed ring? We often get this question at the events we visit with our Perpetual Plastic Project installation. Must be a lot, you’d say. Well, we would like to show you exactly how many plastic cups you need. The answer surprised even us. You actually do not need many cups at all.

Recycling plastic for 3D printing

For the following examples we calculate as if all of the waste material (used plastic cups or bottles) is transformed into a printed object. So the weight of the rings or other 3D printed items is the weight of plastic that we need out of plastic cups or bottles.

One plastic cup equals two rings

We’d explain this better by giving a few examples. As you can see in the image below, the weight of two of our 3D printed rings is 3 grams. One cup made of PS (polystyrene) is also 3 grams, so you can get two of the rings out of one plastic cup.


Phone case made out of bioplastic

You can print a phone case, like the Fairphone case you see in the image, out of recycled plastic (more about the Fairphone, The weight of the phone case is 22 grams. If you use cups of bioplastic of 6,5 grams each, you will need 4 cups to get one phone case. Think about it...just 4 used plastic cups and you have a perfectly fine new phone case!



Surf fin out of PET bottles

What if you lose or break your surfboard fin while surfing and you happen to have a 3D printer nearby? Wouldn’t it be great if you could just gather some PET bottles at the beach, which are usually scattered around sadly enough, and print your own! At least, that’s our vision for recycling plastic bottles in the future. 

As we mentioned before in a previous blog post about plastics that can be recycled for 3D printing, it is really hard to recycle PET into high quality filament. Recently we’ve managed to print the surfboard fin in the image from recycled PET filament. However, it is still tough to recycle PET for 100% and get good quality. In the industry they usually add virgin material. 
The surfboard fin weighs 87 grams. As a 1 liter PET bottle weighs 22 grams, you would in our envisioned future only need 4 PET bottles to print your own new surfboard fin.


So, how many cups do you need? The answer differs a little for every material, but in general we can say that you only need half a plastic cup to get one of our PPP rings. Now you know you’d better think twice before you throw away your seemingly worthless plastic waste, it might be just what you need.

PS. You might not know me yet, so let me introduce myself briefly. I'm  Eveline van Berchum. I'm an online communications specialist. Currently I'm helping out the guys from the Better Future Factory with their online communications. Thanks to them I'm also learning more about recycling plastics and 3D printing myself.