Plastic waste is becoming a massive issue, and solutions to deal with 3D printer waste are emerging.
One approach was recently announced by Germany’s Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM). They observed that there are two types of waste:
Industrial waste that is generally homogeneous and easier to source
Consumer waste that is random, dirty, and mixed with other plastic materials
The latter is far more challenging to deal with, and this is why most waste recycling programs producing 3D printer filament tend towards the industrial sources.
IFAM took on the challenge of consumer plastic waste, and specifically attempted to produce usable polypropylene 3D printer filament.
As the source, they used a typical regional plastics recycling facility that accepts consumer waste. This service attempts to sort plastics into categories, including polypropylene.
However, the material from this source is not guaranteed to be pure. The sorters can make mistakes, and there will be residual amounts of other plastic materials mixed in. That generally prevents the use of this source of material to make proper 3D printer filament.
IFAM devised an interesting process to refine the sorting. The input material was ground up into more-or-less uniform small bits and washed. Then they used an infrared scanner to separate the non-polypropylene bits from the desired material.
The resulting material should have been near-pure polypropylene.
These bits were then used in a typical filament production process to produce spools of polypropylene filament. The filament was then tested in standard desktop 3D printers and found to be quite functional. In fact, they say the purity of the recycled polypropylene was 99.8%, and that’s as good as regular non-recycled polypropylene.
It’s not clear whether this is a financially feasible approach for large-scale polypropylene recycling, but it is a step in the right direction.
Can we do this for other plastics, too?
Via Fraunhofer
