This week we continued to work on our filament extruder. We spent time exploring the possibility of producing filament from other materials

Trial

We tested our filament extruder with ABS pellets and it was a resounding success so it was time to test the device with another material: the material of choice was PET. And PET is used in things like:

plastic bottles.

If it was possible to extrude filament using PET from the current model of the device we assembled, then it would present a great opportunity to use waste plastic bottles  and recycle them to make 3-D printer filament. The only potential pitfall was that our machine was not calibrated for producing filament plastic bottles.

We cut up a single bottle into smaller plastic pellets to see if it was possible to extrude at all. A small strand of filament was produced and we saw it fit to do a full scale testing.

 We would cut up the plastic bottles into small flakes like this.

 

Error

We then decided to do thorough testing with a much larger batch of PET. All seemed to be going well until in quick succession the machine start burning the plastic, producing inconsistent amounts filament and finally jamming.

It was fortunate that the  machine was not damaged and we were able to use the machine again with ABS.

Results

Although there still seemed to be some potential for using flakes of PET to produce filament it was clear it was not possible to do with our machine.

I still learnt a few things this past week and know that I clearly understand the operations of the filament extruder.

I also gained a better appreciation of plastic recycling and my interest in recycling things has also been stimulated. Well- whenever someone  looks at the bottom of a  bottle they have been drinking from and asks me what this symbol means:

I will say ” that’s the code for PET. You should recycle that”