Precious plastic is an open source initiative started in 2013 by Dave Hakkens to encourage more plastic recycling around the world. As part of his internship for Production Technology at KEA, Dennis Simonsen built two of the four plastic recycling machines for Material Design Lab.

The world is drowning in plastic. One of the main characteristics that makes plastic such a popular material proves to be the major problem when it comes to the end of life of our products. It is a very slow to degrade. Even if we stopped using producing virgin plastic today, we still have over 50 years worth of this material sitting in landfills and polluting our oceans and streams. We need more solutions for what to do with all this waste.

Precious plastic was first started in 2013 by Dave Hakkens as his graduate project. It has since evolved and there is now an open source community of plastic recyclers growing and prospering around the world.

Material Design Lab had always been eager to get involved in the project but we lacked the time and skills needed to get the project off the ground. That is where our intern, Dennis Simonsen, came in. Dennis studied Production Technology at KEA and had to complete an internship as a part of his education. He had also been aware of the Precious Plastic community, loved the concept and so he was happy to be involved in starting up the machine building for us.

Precious plastic provides the blueprints for four machines on their website. We didn’t have the time or budget to build all four machines so we let Dennis pick the two machines he would like to work with in the 8 weeks he had for his internship. The two machines he choose were:


This is the first machine needed to shred the plastic into tiny flakes so that it can be transformed into a new material.  It is a good idea to sort and separate the different types of plastics before using the shredder. This will limit the amount of cross contamination early on and make it easier further down the line. All the plastic should have any labels removed beforehand and it will also needed to be washed to remove any residue from it’s former life. The machine should be cleaned out before a different grade of plastic is used.


 Injection molding is a common practice in the plastic industry, With this particular machine, the plastic flakes are heated up and pushed down into a mold. This machine is useful for producing small objects in large quantities. It is a good idea to spend the time and effort on making the molds as a good mold will last for many cycles.